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• du . --max-depth=1 -m -h : veure tamany directoris de primer nivell

• Les comandes de Caldera son a /usr/man/whatis. Compte : ocupa 107 K !
• Els paquets instalats de SuSE 7.2 tenen una entrada a /usr/share/doc/packages. Cada comanda es un directori, amb BUGS, INSTALL, MANUAL, etc. Per buscar una comanda o veure si es instalada, quan ocupará, es molt pràctic el "SuSE help-center".
• Els paquets instalats de Red Hat 7.2 tenen una entrada similar a /usr/share/doc/.
• Es molt interessant el fitxer /etc/fstab, que conté els perifèrics coneguts. Per exemple, s'hi pot comprovar que SuSE del floppy en diu /media/floppy a 7.2, en diu /floppy a 6.2, mentre RedHat n'hi diu /mnt/floppy.

  El fitxer /etc/mtab conté els perifèrics activats (muntats).

• Es també interessant el fitxer /etc/rc.d/rc.sysinit, que només s'executa un cop cada "boot". S'ha de mirar en paralel amb less /var/log/messages. Buscant millor, podem veure que rc.sysinit es crida des /etc/inittab. Aquí s'expliquen els runlevel, de 0 a 6. Per a més informació, fer man init, que jo diria que es de lectura molt recomenable. N'he fet una pàgina .
• Es impresionant ho bé que va el TAB, el vell tabulador. Proba-ho ! En una command-line, pica dues lletres ("st", per exemple) i després 2 cops TAB. Surtem totes les possibles comandes que comencen per "st". Si nomes n'hi ha una, te la posa directament a la command-line amb el primer TAB. Aixó també es vàlid per noms de fitxers ! Si hem de fer un "RPM", per exemple, només cal posar les primeres lletres en lloc de la ristra que hi ha al seu nom. Recorda : TAB.
• Fantàstic el servei proporcionat per el man
  Usualy under
  /usr/local/man /usr/share/man /usr/X11R6/man
  
  Sections :
  • man 1 intro - introduction to user commands
  • man 2 intro - introduction to system calls
    man 2 bind
    man 2 pipe
    man 2 socket
  • man 3 intro - introduction to library functions
    man 3 string
  • man 4 intro - introduction to special files
  • man 5 intro - introduction to file formats
  • man 6 intro - introduction to games
  • man 7 intro - introduction to conversions and miscelany section
  • man 8 intro - introduction to administration and privileged commands

• Al fitxer /etc/hosts hi posem els nicknames ( o aliases ) de les adreçes IP mes conegudes. Es fa servir si /etc/host.conf conté "order hosts,bind".

• When a program is executed, the process running the program opens three file descriptors, which are places the program sends its output and gets its input from :
  0 (standard input), 1 (standard output), and 2 (standard error).

  The redirect output symbol (>) is shorthand for 1>, which tells the shell to redirect standard output.
  Similarly, < is short for <0, which redirects standard input.
  The symbols 2> redirect standard error.

  cat x y 1> hold1 2> hold2 cat x y 1> hold 2>&1 file descriptor 2 to be duplicate of file descriptor 1. ls > dirlist 2>&1 direct both standard input and error to file dirlist ls >> dirlist 2>&1 direct both standard input and error to file dirlist in append mode both ls 2>&1 > dirlist only standard output to dirlist X > /tmp/x.out 2>&1 iwconfig 2> /dev/null ignore standard error program &>> result.txt equivalent to "program >> result.txt 2>&1" ping 8.8.8.8 &>> /dev/null ignore all output !

  See page 487 or LDP

  Defining log inside your code instead of crontab :
  Instead of putting

  &>> your_file.log

  ... behind a line in "crontab -e", I use

  #!/bin/bash exec &>> your_file.log

  ... at the beginning of a bash script.

  Advantage: you have the log definitions within your script. Good for Git etc.

• Es molt interessant el PERFIL, per personalitzar els alias de Linux, el PATH, etc.
  • Al Caldera ( amb BASH ) es el fitxer ".profile-private" del directori $HOME.
  • Al SuSE 7.2 ( amb BASH ) , per el (x)Terminal, es el fitxer /etc/profile.
  • On RedHat 7.2 ( with BASH ) , the environment is set at /etc/profile, and system wide functions and aliases are set at $HOME/.bashrc (even Xconsole), o /etc/bashrc.
  
  Per exemple, per modificar el $PATH, hi posem :
  PATH="$PATH:/home/usuari/funcions:"

  Tip for newcomers : learn the sequence of initialization files that occurs before you get to a command prompt, and understand the difference between profile/login initialization and rc subshell initialization.

  
  (from ~/.bashrc) Bash knows 3 shells :
  • login shell - ~/.profile
  • normal shell
  • interactive shell - ~/.bashrc

  See diferences at "man bash" at Knoppix ! (login shell and interactive shell)

• In bash, you can make the cd command a little smarter by setting the CDPATH environment variable. If you cd to a directory, and there's no directory by that name in the current directory, bash will look for it under the directories in CDPATH, as
  export CDPATH=$HOME/se:$HOME/se/selinux:$HOME/se/selinux/src

• Rexx per Linux : read here

• Engegar amb command line o X-windows ?
  Es tria al fitxer /etc/inittab, que pot tenir
  id:3:initdefault o id:5:initdefault

  I, cap el final

  x:5:respawn:/usr/bin/X11/xdm -nodaemon o x:5:respawn:/opt/kde/bin/kdm -nodaemon
  
  See page 147. Una manera mes dinàmica es :
  LILO: linux 5
• Hot Keys
  • stty -a displays actual settings
  • intr will become SIGINT
  • $ stty intr ^Q sets Ctrl-Q to generate SIGINT.
  • termios(3) explains some of the low level user programming used to associate terminal-generated control characters to signals. Lew Pitcher

• comandes interessants ...
  • top - list processes
  • df - local storage
  • ps -- running processes
  • free - free and used memory
  • lsblk - mounted devices
  • strace - trace system calls and signals

• Devices interessants i nomenclatura.

  Veure "device names", o man fdisk o hdparm

  • discs IDE : /dev/hd[a-h]
    • /dev/hda1 = primera partició primaria del primer disc IDE. In GRUB, it becomes hd0
    • /dev/hda5 = primera partició lògica del primer disc IDE.
    • /dev/hdb = segon disc IDE, slave disk on primary IDE controller.
    • /dev/hdc = tercer disc IDE, master disk on secondary IDE controller.
    • /dev/hdd = quart disc IDE, slave disk on secondary IDE controller.

  • discs SCSI : /dev/sd[a-p] Així, /dev/sda es el primer disc SCSI. /dev/sda1 = primera partició del primer disc SCSI.
  • discs ESDI : /dev/ed[a-d]
  • discs XTI : /dev/xd[ab]
  • CD-ROM : /dev/scd0, also known as /dev/sr0.
  • disc floppy : /dev/fd0
    Si a la comanda mount /dev/floppy ens dona el missatge only root can mount /dev/fd0 then include user in /etc/fstab, near noauto.
  • ports : /dev/ttyS0 = COM1 (0x03F8h, IRQ=4), /dev/ttyS1 = COM2 (0x02F8h, IRQ=3)
  • IDE : ide0 (0x1F0-0x1F7, 0x3F6, IRQ14) ide1 (0x170-0x177, 0x376, IRQ15)

• This should cause the modem (assuming it's on COM4 in Windows-speak) to dial the phone number 555-1234 :
  echo "ATDT555-1234" > /dev/ttyS3

• Una cosa curiosa es el directori proc.
  • cat /proc/cmdline : veure com s'ha arrancat el kernel,
  • cat /proc/interrupts | grep ide : see disk activity.
  • procinfo : display system status gathered from /proc
  • cat /proc/cpuinfo - veure CPU
  • cat /proc/meminfo - memoria, as top (més elegant)

• Kernel modules - are services that are included in the kernel as needed, and removed from memory when done. Have a look at /lib/modules

  Advantadges :

  • very convenient under tight memory constraints.
  • if the harware configuration is not known at boot time, then loading the drivers as modules allows to first query (or set) the hardware before loading the code.
  • modules are not bound by the GPL, so developers are free to create binary modules and distribute them without needing to release their source code.

  Related commands :

  • lsmod - list loaded modules.

  • rmmod - unload loadable modules. Used by kernel on modules loaded with the -k flag.

  • depmod - handle dependency descriptions for loadable kernel modules.
    Use depmod -ae to solve all dependencies.
    From "help depmod" : depmod creates a makefile-like dependency file, based on the symbols it finds in the set of modules mentioned in the configuration file. This dependency file is later used by modprobe to aumatically load the correct module or stack of modules

  • insmod - install loadable kernel modules.

  • modprobe - high level handling of loadable modules.
    Using modprobe eth0 rather than insmod 3c509 will try to use the alias in /etc/modules.conf rather than the real module name.
    modprobe functions in much the same way as insmod, but it also loads any other modules that are required by the module you want to load.

  • other : ksyms, modules, modinfo, modules.conf.

  • Very good on-line book.

  Resum :

  lsmod = display modules modprobe -r nom = remove module

• Kernel commands and utilities
  • klogd - kernel log daemon.
  • ksymoops - decode kernel Oops.
  • objdump - display information from object files.
  • Spend some time reading this book.

• Security bits.

  When a file is created, it is assigned security permissions. There are 3 levels of security : user, group and other. Also, file attributes are defined and may be modified using chmod :

  • 4000 - SetUID on execution (changes to userid 0 upon execution).
  • 2000 - SetGID on execution (changes to system group upon execution).
  • 1000 - Set the sticky bit (leave the program in swap space). Read wiki or linunix

  Useful commands :

  • chmod g=r filename : afegir permís de lectura pel grup (u/g/o/a, r/w/x)
  • $ chmod +x prog-name : make it executable
  • find / -perm +4000 : display all SUID files
  • find / -perm +2000 : display all SGID files
  • cd - : go to previous directory !
  • "sudo find ~/ -user root" - mostrar els fitxer dels que no es owner el usuari actual sino "root"

• file system structure
  • /bin - executables for every user
  • /boot - kernel images, system map, bootstrap, etc
  • /dev - special files that represent hardware devices
  • /etc - configuration files
  • /home - user's home directories
  • /lib - system libraries
  • /mnt - system mount points for other filesystems
  • /proc - virtual file system containing kernel and process info
  • /root - home directory for root user
  • /sbin - system admin executables, system scripts
  • /usr - Unix System Resources
    • /usr/src/linux - kernel source
    • /usr/doc - documents by package, as /usr/doc/x3270-3.1.1.9/Docs/Resources.
      Maybe under /usr/share/doc, look for index.htm under
      • /HOWTO/en-html
      • /FAQ/Linux-FAQ

  Another point of view : url

  • /bin (and /sbin) were intended for programs that needed to be on a small / partition before the larger /usr, etc. partitions were mounted.
    These days, it mostly serves as a standard location for key programs like /bin/sh, although the original intent may still be relevant for e.g. installations on small embedded devices.
  • /sbin, as distinct from /bin, is for system management programs (not normally used by ordinary users) needed before /usr is mounted.
  • /usr/bin is for distribution-managed normal user programs.
    There is a /usr/sbin with the same relationship to /usr/bin as /sbin has to /bin.
  • /usr/local/bin is for normal user programs not managed by the distribution package manager, e.g. locally compiled packages.
    You should not install them into /usr/bin because future distribution upgrades may modify or delete them without warning.
    /usr/local/sbin, as you can probably guess at this point, is to /usr/local/bin as /usr/sbin to /usr/bin.
  • in addition, there is also /opt which is for monolithic non-distribution packages,
    although before they were properly integrated various distributions put Gnome and KDE there.
    Generally you should reserve it for large, poorly behaved third party packages such as Oracle.

• partition planing
  • /
  • /home
  • swap
  • /boot (if you have cylinder problems)

  Others could be :

  • /var
  • /tmp
  • /usr

  Reasons :

  • Security : set /boot partition read-only
  • Isolating : /home and /var, so root partition doen't get filled.
  • Convenient : /home and /usr, so upgrades keep desktop info.

• arrencada del daemons
  • rpc.portmap - sota RH 6.2 des /etc/rc.d/rc3.d/S11portmap
  • rpc.mountd ?
  • rpc.nfsd ?

• how to restart a daemon :

  • syslogd (to read /etc/syslog.conf)

  • inetd (to read /etc/inetd.conf)
    # kill -SIGHUP inetd ( or # kill -HUP - SuSE 7.2)
    or
    # /etc/rc.d/init.d/inetd restart (reload ? SuSE 7.2)

• loopback device - ara l'estic estudiant.
  • man losetup
  • The Loopback Root Filesystem HOWTO
  • 127.0.0.1 is the loopback interface, which you will have even if you have no real network connection.
  • lo interface - this interface is for packets from a local process that are destined for a local process. See page 511.
  • En un Mailing List, he trobat
    It is configurable. options loop max_loop=n in modules.conf, or if youre using it builtin max_loop=n at kernel options.
  • Steps for loop mounting under Linux
    Loop mounting an ISO file under Linux allows you to view and use the ISO file as if you have burned it to a CD. No CD writer or blank CDs are required to do this. You must login as root to use the following commands.
    /mnt/path must exist (mkdir -p /mnt/path)
    To loop mount an ISO file using Linux run mount -t iso9660 openlinux.iso /mnt/path -o loop,ro
    After the ISO is mounted you can cd /mnt/cdrom to use the CD as if it was in your drive.
    When finished use the command umount /mnt/cdrom to unmount the ISO file.
    You cannot be in the /mnt/cdrom directory when you run these commands.

    Before : losetup /dev/loop0 /home/theISOS/rh7.3.1.iso
    After : losetup -d loop0

    We are assuming that you already have a CD/DVD in your SLED/SLES base machine. Now we want to create ISO image of that CD/DVD.
    Using DD command:

    person@NOVELLDESK:~> dd if=/dev/cdrom of=SLED.iso bs=4k status=progress

    Using the CAT command you can achieve same result:

    person@NOVELLDESK:~> cat /dev/cdrom > SLED.iso

    Lets use it. We are assuming that you are in same directory in which you have created the ISO of your CD/DVD. First create the mount directory. Second, mount it. Third, use it :

    person@NOVELLDESK:~> sudo mkdir /mnt/ISO person@NOVELLDESK:~> sudo mount SLED.iso -o loop /mnt/ISO

    url

• md5 - ara l'estic estudiant. Si anem a ftp://raleigh.linux.hal.com/pub/SuSE/i386/en/8.0 veurem que hi ha un fitxer de tipus md5.
  • Qué es ?
    When you download a file, you can use MD5 to guarantee that you have the correct, unaltered file by comparing its hash with the original. You are essentially verifying the file's integrity.
  • Com es fa servir ?
    • Baixem els 3, 4, o 5 CD's (*.iso) i un "*.md5".
    • El contingud del ".md5" es com això :
      ecc7b5c6b0025de6c0df63adebaa457e rh-6.2-es-i386-cd1.iso 8fc64afbded4685b82cf19b169fcb9cf rh-6.2-es-i386-cd2.iso
    • Verifiquem que el CD1 no ha tingut modificacions amb la comanda :
      md5sum -b rh-6.2-es-i386-cd1.iso
      i comprovant que coincideix amb la firma descrita (ecc7b5c6b0025de6c0df63adebaa457e).

• modem - ara l'estic estudiant. Few PPP scripts.

Configuració i visualitzacio dels parametres del(s) disc(s) dur(s).

• fdisk - display the partitions and details like file system type, but it does not report the size of each partitions.
• sfdisk - similar to fdisk, it can display the size of each partition.
• cfdisk - linux partition editor with an interactive user interface based on ncurses.
• parted - another command line utility to list out partitions and modify them if needed.
• df - prints out details about only mounted file systems.
• pydf - improved version of df, written in python, it prints out all the hard disk partitions in a easy to read manner.
• lsblk - lists out all the storage blocks, which includes disk partitions and optical drives. Details include the total size of the partition/block and the mount point if any.
• blkid - prints the block device (partitions and storage media) attributes like uuid and file system type.
• hwinfo - a general purpose hardware information tool and can be used to print out the disk and partition list.
• inxi - can display information about various hardware components present on the system. To display information about the disk drives and storage devices use the "-D" option.

binary tides -

fdisk is the partition table manipulator

S'hi ha de tenir molt de compte. La part "descriptiva" es la comanda fdisk -l, que treu un llistat de tots els discs i les seves particions. Per exemple :

La llista de possibles tipus de particions és :

El disk de guindows amb NTFS es veu com fuseblk a Ubuntu

7 ways to determine the file system type in Linux

• df -Th
• fsck -N /dev/sda3
• lsblk -f
• mount | grep "^/dev"
• blkid /dev/sda3
• sudo file -sL /dev/sda3
• cat /etc/fstab

Fem servir la comanda :

Verificar i reparar el sistema de fitxers (as chkdsk) : fsck (root only).

Read tecmint

Dont run it on disk but on partition :

The correct command would be:

That would feed the first partition of first sata hard drive, not the first sata disk itself.

fsck cannot check root partitions on a running machine since they are mounted and in use. However, even Linux root partitions can be checked if you boot into recovery mode and run the fsck check. To do so :

1. power on or reboot your machine through the GUI or by using the terminal:
   ubuntu@ubuntu:~$ sudo reboot
2. press and hold the shift key during boot-up. The GNU GRUB menu appears.
3. select Advanced options for Ubuntu
4. then, select the entry with (recovery mode) at the end. Let the system load into the Recovery Menu.
5. select fsck from the menu.
6. once finished, select resume at the recovery menu to boot up the machine.

ask ubuntu

Try testdisk :

url

20210827, 4TB :

• bad jump in fat partition
• bad number of sectors per cluster

mount USB official guide

• MBR (ntfs)
• GUID partition table (ext4)

If you require Guindows compatibility, use NTFS

If not, use ext4 (it has journaling)

how to geek

Read ext4 docu

You got caught by ext4lazyinit

ext4 doesn't format the disk per se. It just lays down an image of a block and marks some super blocks, then after 'formatting' is complete, ext4lazyinit kicks in and formats the drive in the background.

For a 4TB drive, this will take a significant amount of time and it will impact write speed unless you up the priority of the task with:

If you want to use ext4 on large external drives, it pays to be aware of this gotcha and to keep an eye on the ext4lazyinit task so that you can use the drive when it's finished.

By default the mkfs.ext4 runs with the lazy_itable_init and lazy_journal_init enable. You can run the command

to force the full initialization before the command returns back to the shell. Mind you this take a while on a 4TB file system.

linux mint forum

To pass the SMART commands through to the hard drive SAT (SCSI ATA Translation) is used.

So you can use Windows XP and HDDScan

There are at least 6 separate command line tools used to label a partition - the program used depends on the partition's filesystem type:

• for FAT16 and FAT32 partitions, use mlabel from the mtools package
• for NTFS partitions, use ntfslabel from the ntfs-3g package
• for ext2, ext3, or ext4 partitions, use e2label
• for JFS partitions, use jfs_tune
• for ReiserFS (v3) partitions, use reiserfstune
• for XFS partitions, use xfs_admin

superuser

• list network interfaces :
  $ ip link show

  PCI devices : see new naming - enpXsY signifies that it's a pci device (from the p), on pci bus X, in slot Y

• display PCI (internal) wireless adapters :
  $ lspci ; look for "Network controller" or "Ethernet controller"

  Display kernel module in use (Broadcom BCM4318) :

  $ lspci -nnkd 14e4:4318

• verify wifi is not disabled :
  $ rfkill list ; hardware switch !

• display USB wireless adapters :
  $ lsusb ; look for "wireless", "WLAN", "wifi" or "802.11"

• check devices are recognized properly
  $ lshw -C network

Network troubleshooting, [netfix]

ifconfig -a see own devices, IP + broadcast address, mask, etc. [root] ifconfig eth0 down bring down the ethernet interface ifconfig eth0 up bring up the ethernet interface ping localhost verificar accés al protocol ping <IP propia> verificar accés a la interficie ping -f [host] : flood ping route view routing table and gateway ping <IP GW> verificar accés al gateway (default router) ping www.cdrom.com verificar accés al DNS netstat display the status of all TCP/IP network services traceroute maps out the route a packet takes to the target host tcpdump packet sniffer RH6.2 - tcpdump-3.4-19.rpm Better is snort. whois as whois seattlewireless.com strobe try to open every socket sequentially nmap utility to scan the port use {use with sudo always} fuser identify the process using a file or a socket lsof list of open files lsof -i -n -P arp -a display what machine has a given MAC, manage the ARP cache nslookup / dig convert IP to name, veure qui té una adreça IP - gethostbyaddr (?) getent get entries from administrative database

Al SuSE 6.4, el tamany màxim del ping es 65467.
Al Caldera 2.4, 65.469 diu "too large", però 65.468 (i 65.466) fa un "dump", i 65.467 (i 65.465) senzillament no va.

169.254.64.0 is a network reserved for autoconfiguration

Top

Personal Computer Memory Card International Association

• cardctl config -
  SuSE RH Socket 0 no pcmcia driver in /proc/devices not configured (no card) Vcc 3.3V Vpp1 3.3V Vpp2 3.3V interface type is "cardbus" irq 5 [exclusive] [level] function 0: io 0x0100-0x017f [32 bit]

• cardctl status -
  SuSE RH Socket 0 no pcmcia driver in /proc/devices no card (no card) 3.3V CardBus card function 0: [ready]

• cardctl ident -
  SuSE RH Socket 0 no pcmcia driver in /proc/devices no product info available product info: "IBM", "10/100 EtherJet CardBus", "IBMC-10/100", "1.04" manfind: 0x00a4, 0x0113 function: 6 (network) PCI id: 0x115d, 0x0003

• lsmod -
  SuSE RH af_packet 11648 (autoclean) pcmcia-core (only) ds 6896 i82365 23440 pcmcia_core 43936 [ds i82365] ipchains 33408 (unused) *** no card *** tulip_cb 33440 cb_enabler 2784 [tulip_cb] af_packet 11648 (autoclean) ds 6896 [cb_enabler] i82365 23440 pcmcia_core 43936 [cb_enabler ds i82365] ipchains 33408 (unused) *** eth0 *** serial_cs 5664 tulip_cb 33440 cb_enabler 2784 [tulip_cb] af_packet 11648 (autoclean) ds 6896 [serial_cs cb_enabler] i82365 23440 pcmcia_core 43936 [serial_cs cb_enabler ds i82365] ipchains 33408 (unused) *** eth0 + mdm ***

• lspci - list all PCI devices. El mode "super-verbose" es lspci -vvx.

• modprobe /lib/modules/2.4.7-6/kernel/drivers/pcmcia/yenta_socket.o

• modprobe i82365

• insmod ./xircom_tulip_cb.o

• /etc/rc.d/init.d/pcmcia stop - shut down the PCMCIA system

• /etc/rc.d/init.d/pcmcia start - (re)start the PCMCIA system

• configuració PCMCIA
  RH : /etc/sysconfig/pcmcia SuSE : /etc/rc.config PCMCIA=yes START_PCMCIA="yes" PCIC=yenta_socket i82365 PCMCIA_PCIC_OPTS=""

• /etc/pcmcia/config.opts

• /lib/modules/2.4.7-6/pcmcia/*.o - all modules

• /var/lib/pcmcia/stab - device info for each socket

Top

• Recuperar el Main Boot Record (SuSE 7.2) : lilo -u /dev/hda

• Shell commands (use "help" at bash)
  alias /unalias bg / fg cd echo eval exec exit export help popd pushd pwd set / unset type umask

• Si has fet un cat de un fitxer binari, et pot quedar la configuració de la pantalla en modus gràfic. Per recuperar-lo, es pot fer un reset.

• Veure els processos que consumeixen CPU : top (root only).

• how to set the date :
  p9111-520:~ # date 11241431 { means MMDDhhmm - no Year ? } Wed Nov 24 14:31:00 CET 2010 p7029-6E3:~ # date -s "11 NOV 2011 12:35:00" Fri Nov 11 12:35:00 CET 2011
• muntar CD o DVD :
  # mkdir /mnt/cdrom # mount -t iso9660 /dev/scd0 /media/cdrom
• Esborrar el LILO del MBR ( Master Boot Record ) : boot a DOS floppy with FDISK.EXE and run FDISK /MBR.

• Network configuration, files and programs
  resolv.conf configures the DNS client. Not present => disabled. modules.conf configure the devices

• nombre de fitxers oberts :
  ps -ef | grep -v grep | grep nodejs ; get process ID sudo lsof -i -n -P | grep nodejs ; lsof command

  Display max value at system configuration : "ulimit -a"

  nicolau@mars:~$ ulimit -a ... open files (-n) 1024 #

• Text-mode browser : lynx
  Configuration file : /usr/lib/lynx.cfg (SuSE 7.2)
  So, to install Nessus, we can use :
  lynx -source http://install.nessus.org | sh

  Or, to convert HTML to ASCII, use :

  lynx -dump source.html > ascii.txt

  See the /etc/lynx.cfg file !

• *** Get a network sniffer for ETH0 LAN ***

• Veure els processos actius : ps -A o pstree -d o top La comanda que segueix es kill.

• Veure qui hi ha conectat i que fa : w. La comanda who treu informació similar.

• Veure el LOG del sistema : dmesg. Una manera mes pràctica es dmesg | less.
• Veure el LOG del sistema dinàmicament : tail -f /var/log/messages. I anem a un altre command-line i fem l'acció que volem monitoritzar.
• Símbols de la imatge del VMLINUZ : /boot/System.map

  Símbols dels mòduls del kernel : ksyms (su only). Pots veure els de SuSE amb PCMCIA i TCP/IP funcionant.

• ldd - "List Dynamic Dependencies", print shared library dependencies.

• ldconfig - determine run-time link bindings. Rebuilds the cache. Result is /etc/ld.so.conf
  The directory in which a (new) dynamic library is installed must /etc/ld.so.conf, and ldconfig must be run after that.

• ln - make links between files.
  ln [option] <target file> <link name>

  Samples :

  ln /usr/local/bin x (hard link) ln -s /etc/init.d/pcmcia S08pcmcia (soft link)

  If some program (as rpm) has problems following links, use namei to display the real path.

• tar utility - Manual (1 big page).
  -t : list contents -c : create -x : extract -f : filename follows -u : update -v : verbose -z : use gzip tar -czf tot.tar *.c = create tar -xzf foo.tar.gz blah.txt = extract the file blah.txt from foo.tar.gz

  Compte si volem guardar el PATH sencer !

  cd /home/sebas/cmds tar -cvzf /home/sebas/prova/uno.tgz * tar -tf uno.tgz aturar_VMX.sh crear_backup.log

  No se ha guardat el path. Si el volem guardar, hem de fer aixi

  tar -cvzf dos.tgz /home/sebas/cmds/* tar -tf dos.tgz home/sebas/cmds/aturar_VMX.sh home/sebas/cmds/crear_backup.log

  Compte que si escollim nomes alguns fitxer amb la extensio, no hi ha recursivitat de subdirectoris :

  tar rvf nom.tar /home/nicolau/sebas/sag/*.txt

  Si ho volem fer, ho podem fer directe (pocs fitxers) o amb un fitxer intermig : stackoverflow

  tar -cf my_archive `find ./ | grep '.php\|.html'` ; mind (`) and (') ; find ./ -type f -name "*.php" -o -name "*.html" -exec tar uvf myarchives.tar {} + find . \( -name "*.php" -o -name "*.html" \) -print > files.txt tar cfh my.tar -I files.txt ; use -I or -T depending on the version of tar you use
  tree - visualizador de directorios. Get it here by selecting tree-1.2.tgz

  rdev - query/set image root device, swap device (swapdev, rdev -s), RAM disk size (ramsize, rdev -r), video mode (vidmode, rdev -v) or rootflags (rootflags, rdev -R). (root only)

  This is, rdev outputs /etc/mtab for the current root file system.

  .iso - what to do with an ".iso" file

  Jo tinc "Adaptec Easy CD Creator" versió 3.01a (284), i faig "File" + "Create CD from Disk Image" ... fàcil ! You can use it, without burning a CD !

  To create a ".iso", see mkisofs ! Thanks, Albert.

  dd - convert and copy a file

  Per crear una imatge de un diskette en 1 sol fitxer, fem :

  [sebas@mitp img] dd if=/dev/fd0 of=pm60_1.img

  El tamany ha de ser de 1.474.560, que son 1440 de 1024 bytes.

  Per inicialitzar un DASD (esborrant el vell contingut), es millor fer servir :

  [sebas@s390] dd if=/dev/zero of=/dev/dasdf

  motd - message of the day. The text in file /etc/motd is displayed after a successful login.

  envir seting to edit cmd line:

  set -o vi set -o emacs

  The "^M" things are from dos/windows files: DOS carriage returns are "\n\r", unix "\n". The extra character shows up as "^M".
  Use dos2ux (or dos2unix depending on your flavor of unix) to convert windows text files.

  Manegament de usuaris ( es recomena linuxconf )

  • useradd (low level) or sudo adduser nomusuari, user friendly (interactive)

    Es crea un usuari (fent servir /etc/adduser.conf) amb la clau bloquejada - use passwd
    Use "useradd -D" to display the options to be used - they come from /etc/default/userad
    the mail spool file will be created when the first email comes in - useradd will not create the file

  • userdel/deluser - remove a user.

    Use sudo userdel -r nomusuari to remove its directory and mail spool (/var/mail/old_user)

  • passwd

    Si volem desbloquejar la password d'un usuari, fem passwd -u -f sebas. Després, el usauri ferà passwd per posar-s'en una.

  • force user to change the password : chage -M 0 nomusuari

  • Manual RH 7.0

  mkfs and mkswap - create File System and Swap.

  The bogomips (bogus Meaningless Indicator of Processor Speed) I have got.

  Fes cat /proc/cpuinfo i mira la darrera línia, o bé dmesg | grep Bogo o lscpu

  IBM 9595 (DX2 25 MHz)	24,88
  IBM 330 (DX2 60 MHz)	33,28
  Pentium 90 MHz	35,84
  TP 760 ED (Pentium 133 MHz)	52,84
  S/390 (9672 R74)	301,46
  T30 + Knoppix, 1,8 MHz CPU	3.578,26
  P4 2.519,184 MHz CPU	5.020,05
  T60, cpu 997 MHz	3.324,93
  Raspberry 3B	38,40
  MINIE Ryzen 9	16 x 6587,55

  
  Want to know what it is ? Read this mini-HOWTO or /usr/doc/HOWTO/mini/BogoMIPS under Red Hat.

find - find files

Ignore "find" errors :

Here's a good intro, and here is another.

Esborrar tots els fitxers de una certa extensio, recorrent subdirectoris :

"locate" reads through the mlocate.db database file which contains all file paths in your system.

grep - print lines matching a pattern.
The command takes the form :

Main flags recognized by grep :

Es a dir, el grep fa búsqueda dins de fitxers.

To display all lines in the file1 file that match either the abc or xyz string, enter:

To find the text "pandas" in all "*.py" files from here "." and all subdirs bellow :

"grep" errors :

Use "file <name>" ... and save as UTF-8

Use this syntax :

Busquem "in<TAB", texte "in" seguit de tabulador :

grep uses a dollar sign as a special character matching the end of a line.
So if you actually want to search for a dollar sign, you have to precede it by a backslash (and include the whole search string in single quotes).

You should avoid using egrep and fgrep because they are deprecated commands.
Using grep -E and grep -F is the way forward - linuxhandbook.com

But fgrep lets you just type in that dollar sign :

And you can also use fgrep to match for a dot or a caret without having to precede it with a backslash — which does make things more readable

Si no volem que la shell amb la busqueda surti com a resultat, posarem "sqare brackets" en alguna lletra del pattern : ... then it matches "portmap", but it does not match "por[t]map", One from O'Reilly "Essential System Administration".

Una altra solució :

Buscar un texte en tots els fitxers :

Buscar el texte "logger" a tots els fitxers a partir del directori actual :

Buscar una URL en tots els fitxers :

Stack Overflow

A chroot jail is a way to isolate a process and its children from the rest of the system.

Use the ts tool !

Install it by

• ls -alt = dir /od
• ls -alrS = dir /os
• ls -lb : print octal escapes for nongraphic characters
• what is "total" in "ls -al" ?
  It is the total number of file system blocks, including indirect blocks, used by the listed files. If you run "ls -s" on the same files and sum the reported numbers you'll get that same number.
• ls -s : print the allocated size of each file, in blocks
• ls -d /* : list only directories

Si volem guardar tots els fitxers "*.py" farem :

Used in "/home/sebas/backups/minie/0_fer_3_zips.sh" called by "/home/sebas/eines/0_salva_2_usb.sh"

Display Managers gráficos mas conocidos :

• GNOME Display Manager (GDM)
• KDE Display Manager (KDM)
• Light Display Manager (LightDM)
• LXDM

makeuseof

Display actual display manager :

Use inxi command :

X-Windows started out as one man's project in an office on the fifth floor of MIT's Laboratory for Computer Science. A wizardly hacker, who was familiar with W, a window system written at Stanford University as part of the V project, decided to write a distributed graphical display server.
The idea was to allow a program, called a client, to run on one computer and allow it to display on another computer that was running a special program called a window server.
The two computers might be VAXes or Suns, or one of each, as long as the computers were networked together and each implemented the X protocol.

X has switched the meaning of client and server.
In all other client/server relationships, the server is the remote machine that runs the application (i.e., the server provides services, such as database service or computational service).
For some perverse reason that's better left to the imagination, X insists on calling the program running on the remote machine "the client". This program displays its windows on the "window server."
We're going to follow X terminology when discussing graphical client/servers.
So when you see "client" think "the remote machine where the application is running," and when you see "server" think "the local machine that displays output and accepts user input."

unix haters

stackexchange :

• “X11” is, strictly speaking, a communication protocol

• X11 is also a OSI level 7 protocol ie the format of the datastream over the network and its semantics

• some concepts:

  • X Windows System
    Windowsing system - make it possible for moving windows on display device and interacting with mouse and keyboard

  • X.Org Server
    An open-source implementation of X Windows System by X.Org Foundation.

  • xterm - terminal emulator for X Windows System

  • X Client: an application runs on an X server

Configuration file : there is none. Use "X -configure" to display detected values

You can create it ! xorg.conf documentation

Display actual screen size :

Another way : (xdpyinfo - display information utility for X)

More complete :

Verify using a browser : de.piliapp.com !

How to set a custom screen resolution in Ubuntu desktop :

Try to restart X11 server by "Control" + "Alt" + "Backspace" - much better is sudo startx

Running process :

Log : by defalut X11 log is /var/log/Xorg.n.log, where n is the display number of the Xorg server

Nice error on R0 :

Reconfigure Xorg.conf :

Few interesting commands

How to find video driver in use

• video 2 Linux devices - structure of a V4L driver
• the v4l-utils are a series of packages for handling media devices
• Video for Linux API version 2 (V4L2 API) specification

vi - Linux editor. See man vi for syntax highlighting. See "vi --version"
vi is in one of two modes : text (input) or command. You can enter command mode by hitting ESC.

How do you search for special characters in vi?
Certain special characters ( / & ! . ^ * $ \ ? ) have special significance to the search process and must be “escaped” when they are used in a search.
To escape a special character, precede it with a backslash ( \ ).

Refining the Search - You can make searches more precise by tagging the string with indicators for the following characteristics:

• beginning of line - start the search string with a caret (^)
• end of line - end the search string with a dollar sign ($)
• beginning of word - type "\<" at the beginning of the string
• end of word - type "\>"" at the end of the string
• complete word - /\<myword\>
• wildcard characters - to match any character, type a period (.) in the string at the location to be matched

docs.oracle

• CoolEdit - Linux editor. Download at SourceForge or Home.

• Hex editors :
  • od -h hda_mbr.img (*** warning : swaps bytes ***)
  • khexdit hda_mbr.img (*** best, GUI ***)
  • emacs hda_mbr.img (not yet in hex)
  • hexdump hda_mbr.img (*** best, command line ***)

Top

Read wikipedia startup and init and Systemd

Can be

• Sys V / BSD - /etc/inittab

• systemd - replaces the UNIX System V and BSD init systems - wikipedia

The "rc.local" file on Debian is mostly for compatibility with non-init style systems. forget rc.local

"man init" o "man systemd"

systemd is a Linux bootstrapping system used to start and manage system processes.

In systemd, the target of most actions are “units”, which are resources that systemd knows how to manage. Units are categorized by the type of resource they represent and they are defined with files known as unit files. The type of each unit can be inferred from the suffix on the end of the file.

For service management tasks, the target unit will be service units, which have unit files with a suffix of .service.

Units are representations of resources that systemd knows about.

To verify which "system manager" are you using, do :

How to list (user) services

• wikipedia
• man page
• documentation
• linux logging with systemd +
• good intro on systemd
• systemd syntax
• systemd service details

• unit
• service
• install

uTube

(6) service types

Sometimes we need to ask a "oneshot" service to "Stay" (RemainAfterExit=yes, as leer_cada_5_segundos.py at R4) or we want to run a service at shutdown ...

trstringer

how to use systemctl

systemd offers users the ability to manage services under the user's control with a per-user systemd instance, enabling users to start, stop, enable, and disable their own units.
This is convenient for daemons and other services that are commonly run for a single user, such as mpd, or to perform automated tasks like fetching mail.

The systemd user instance is started after the first login of a user and killed after the last session of the user is closed.

All the user services will be placed in ~/.config/systemd/user/

All the system services are located at /etc/systemd/system

If you want to run services on first login, execute systemctl --user enable service_name for any service you want to be autostarted, as "mars_start.service"

If you want a user service to be run at system boot, use "loginctl enable-linger USERNAME"

*** wiki systemd user services *** writing unit files

If you specify the user/group in the unit file then you should start the service as a system service.
If you want to start the service as a user service then the User/Group is not needed and can be removed from the unit config. You simply start the service when logged in as the current user passing the --user flag to systemctl.

The complete list of options can be read by

By example, the details about "StandardOutput="

If we want to redirect output, the proper way is like this :

Another way to catch all the "echo" lines is by

If we define the StdOutput in the service unit like this :

Then we can read it like this :

I enable MARS start service and verify its status after reboot :

If we are not logged as service "owner", we get "Failed to connect to bus" message

A more complete service could be

If we want a "silent" service, this is the way :

• dont use "nohup"
  The parent is PID 1; it survives as long as the system is booted; there is no end that needs to be survived.
• dont use "&"
  Similarly, you should stay in the foreground; do not try to daemonize.
• do not wrap your script in another script.
  Doing either of these first two things stops systemd from detecting when your program crashed and restarting it, and the third complicates signal handling.
• dont use filename extensions
  .sh is bad practice, IRC channel
• dont use "one" "big" startup service to start few "small" startup services
• "oneshot" is exactly the wrong thing for anything you want to run forever -> use "simple"
• DO use Restart=always.
• DO create an Install section, and configure your service to be a dependency of a target that is started on boot.
• other "process supervisors" : runit (collection of run scripts) or s6

Charles Duffy

First we try to use "network-online.target" in the .service file:

To list we use :

An intermediate solution is (github)

A definitive solution is to use (stackexchange)

Environment variables for a service can be set explicit or in a file

Lets display a list of all runlevels and services used by them:

We do "enable" it by

We can see its contents by

And finally we start it :

"user" and "group" are not needed if it is a "--user" service - url

If you want the service to be started before the user login, don't forget to run:

Docu loginctl

• unix sysadmin - magnific article
• systemd System and Service Manager , syntax , service details
• arch Linux
• loginctl
• how to list services

LinuxJournal, How-To,

Definim la feina a fer a /etc/init.d - "the scripts for controlling the system are placed in /etc/init.d/":

I la activem:

Que llença "S88sebas" ? /sbin/init -> /etc/inittab "si::nom:/etc/init.d" -> /etc/rc.d/rc

init script human descriptions

Place it in /etc/rc.d/rc.local, as:

When executing a script at startup, make sure that the script ends with "exit 0".

On System V based OS’s the /etc/rc.local file is executed by the init process at the end of the systems boot process.

Forget about rc.local

Read UbuntuBootupHowto, include "Writing Services"

Starting Your Software Automatically on Boot using /etc/init.d

If we want to run a command when Ubuntu starts, we edit crontab "crontab -e" and enter this line :

Better dont use @reboot

To execute a script at shutdown or reboot:

1. save your script in /etc/rc6.d
2. make it executable: sudo chmod +x K99_script

Notes:

1. the script in rc6.d must be with no .sh extension
2. the name of your script must begin with K99 to run at the right time.
3. the scripts in this directory are executed in alphabetical order.

Si a /etc/rc.local tenim un print .... on surt ?

• if your command runs an infinite loop, you must be sure to fork the process by adding an ampersand to the end of the command, and prefixing it by "nohup"

• be sure to reference absolute filenames

Few URLs :

• stackoverflow
• cersimple
• medium - create a Linux service with systemd

Les diferències entre Systemd i SysVinit (també conegut com System V Init) són bastant importants, especialment en la manera com gestionen el procés d’arrencada i els serveis en sistemes Linux. Aquí tens un resum :

• 🧱 1. Arquitectura i disseny SysVinit: És seqüencial: executa scripts d’arrencada un darrere l’altre. Utilitza scripts sh (shell scripts) situats a /etc/init.d/. Basat en runlevels (nivells d'execució del sistema). Systemd: És paral·lel i basat en dependències: pot iniciar diversos serveis alhora, segons les seves dependències. Utilitza unitats (*.service, *.target, etc.) situades a /etc/systemd/, /lib/systemd/, etc. Basat en targets, que són més flexibles que els runlevels.
• ⚙️ 2. Gestió de serveis SysVinit: Per iniciar/aturar serveis: service nom_servei start/stop. No té control avançat del servei un cop llançat. Systemd: Usa systemctl per controlar serveis (systemctl start nom.service, systemctl status, etc.). Pot monitorar serveis, reiniciar-los automàticament si cauen, i més.
• ⏱️ 3. Rendiment SysVinit: És més lent en arrencar, perquè fa servir una execució seqüencial. Systemd: Més ràpid, gràcies a l'execució paral·lela i a la gestió més intel·ligent de dependències.
• 🛠️ 4. Diagnòstic i registres SysVinit: Fa servir syslog o altres sistemes de registre externs. Systemd: Té el seu propi sistema de registre: journald (journalctl per veure els logs). Molt útil per veure què ha passat amb un servei (journalctl -u nom.service).
• 📦 5. Adopció i compatibilitat SysVinit: És més antic i encara es troba en sistemes més lleugers o minimalistes (com Alpine Linux). Systemd: És el predeterminat en la majoria de distribucions modernes: Ubuntu, Fedora, Debian, Arch, etc.

When Ubuntu restarts, the very first line in syslog is :

En el Chrome, en veure videos de YouTube ...

Algu ens espatlla el fitxer :

The file starts with non-text data, hence grep is treating the file as binary. This is confirmed by the "file" filename output

systemd-journald is a system service that collects and stores logging data.
It creates and maintains structured, indexed journals based on logging information that is received from a variety of sources:

• kernel log messages, via kmsg
• simple system log messages, via the libc syslog(3) call
• structured system log messages via the native Journal API, see sd_journal_print(3) and Native Journal Protocol
• standard output and standard error of service units.
• audit records, originating from the kernel audit subsystem

free desktop

Query the systemd journal

Nice filter :

20230520 MARS has 4,1 G journal

• display used disk -
  nicolau@mars:~$ journalctl --disk-usage Archived and active journals take up 80.0M in the file system.
• change configuration
  1. edit "/etc/systemd/journald.conf" to
  2. set "SystemMaxUse=100M" and
  3. activate new configuration by "service systemd-journald restart"
• remove old data (from man journalctl)
  • sudo journalctl --vacuum-size=100M retain the most recent 100M of data
  • sudo journalctl --vacuum-time=10d delete everything but the last 10 days
• verify, modify & fix errors :
  nicolau@mars:~$ journalctl --verify nicolau@mars:~$ systemctl status systemd-journald Warning: Journal has been rotated since unit was started. Log output is incomplete or unavailable. nicolau@mars:~$ sudo systemctl restart systemd-journald
• If systemd-journald.service is restarted using systemctl restart or equivalent operation instead of a pair of separate systemctl stop and systemctl start commands (or equivalent operations), these stream connections are not terminated and survive the restart. It is thus safe to restart systemd-journald.service
  free desktop

ask ubuntu

See its foss - 7 Simple Ways to Free Up Space

Top

• How to know if the kernel is 32-bit or 64 bit ? Per veure-ho es pot fer uname -m
  • if "i386" or "i686" then 32 bit
  • if "x86_64" then 64 bit
  • if "ppc64" then 64 bit - wiki.

• How to know the kernel version you are running. Per veure-ho es pot fer uname -a
  • cat /proc/version
  • cat /etc/issue {the best, IMHO}
  • ls -al /boot
  • ls -al /lib/modules

• kernel versions related to distribution versions

  Caldera 2.2	2.2.5 (Apr 99)
  Caldera 2.3	2.2.10 (Sep 99)
  Caldera 2.4	2.2.14
  Caldera 3.1	2.4.2-11 (Jul 01)
  Caldera 3.1.1	2.4.13-9
  Debian 1.1 Buzz
  Debian 1.2 Rex	2.0.27
  Debian 1.3 Bo
  Debian 2.0 Hamm
  Debian 2.1 Slink	2.0.36
  Debian 2.2 Potato	2.2.19 (Aug 00)
  Debian 3.0 Woody	2.n.nn (Jul 02)
  Knoppix 3.3	2.4.22 (24092003)
  Knoppix 3.7	2.4.27 & 2.6.9 (08122004)
  Mandrake 6.1 Helios	2.2.13 (Sep 99)
  Mandrake 7.0 Air	2.2.14 (Jan 00)
  Mandrake 7.1 Helium	(Jun 00)
  Mandrake 7.2 Odyssey	2.2.17-21.mnk (Oct 00)
  Mandrake 8.0 Traktopel	2.4.3-20mdk (May 01)
  Mandrake 8.1 Vitamin	2.4.8 (Sep 01)
  Mandrake 8.2 Cooker	2.4.18 (Mar 02)	mini system (65 MB)
  Mandrake 9.0
  Mandrake 10.0	2.6.3 (Jun 04)
  Mandrake 9.1	2.4.21 (Mar 03)	KDE 1.3, Gnome 2.2, Apache 2, Mozilla 1.3, OpenOffice 1.0.2
  Mandriva Linux 2007 Spring		KDE 3.5.6, GNOME 2.18, Firefox and Thunderbird 2.0 Metisse, the most innovative accelerated 3D desktop technology; open source telephony with WengoPhone; Google desktop applications including Picasa and Earth;
  Red Hat 1.0 Mothers-Day	1.2.11
  Red Hat 1.1 Mothers-Day	1.2.11
  Red Hat 2.0	1.2.13 (Fall 95)
  Red Hat 2.1	1.2.13-1
  Red Hat 3.0.3	1.2.13-2
  Red Hat 3.0.4 Rembrandt	2.0.10 (Aug 96)
  Red Hat 4.0 Colgate	2.0.18-5
  Red Hat 4.1 Vanderbilt	2.0.27 (Jan 97)
  Red Hat 4.2 Biltmore	2.0.30-2
  Red Hat 5.0 Hurricane	2.0.32-2
  Red Hat 5.1 Manhattan	2.0.34-0.6
  Red Hat 5.2 Apollo	2.0.36-0.7
  Red Hat 6.0 Hedwig	2.2.5-14
  Red Hat 6.0 Lorax (beta)	2.2.12 (Jun 99)
  Red Hat 6.1 Cartman	2.2.12-20
  Red Hat 6.1.92 Piglet (beta)	2.2.16-17 (Feb 00)
  Red Hat 6.2 Zoot	2.2.14-5
  Red Hat 6.9.5 Pinstripe (beta)	2.2.15-2.5.0 (Jul 00)
  Red Hat 7.0 Guiness	2.2.16-22 (Sep 00)
  Red Hat 7.0.90 Fisher (beta)	2.4.0 (Jan 01)
  Red Hat 7.0.91 Wolverine (beta)	2.4.1 (Feb 01)
  Red Hat 7.1 Seawolf	2.4.2-2
  Red Hat 7.1.93 Roswell (beta)	2.4.6-3 (Jun 01)
  Red Hat 7.2 Enigma	2.4.7-6 / 2.4.7-10 / 2.4.9-13
  Red Hat 7.3 Valhalla
  Red Hat 8.0 Psyche	2.4.18	gcc 3.2, glibc 2.2.90, GNOME 2.0, KDE 3.0.3, XFree86 4.2.0
  Slackware 3.0	1.2.13 / 1.3.18
  Slackware 3.1 Slackware96	2.0.27
  Slackware 3.9	2.0.37 (May 99)
  Slackware 4.0	2.2.6 (May 99)
  Slackware 7.0	2.2.13 (Oct 99)
  Slackware 7.1	2.2.16 (Jun 00)
  Slackware 8.0	2.2.19 / 2.4.5
  SuSE 4.2	1.3.97
  SuSE 5.0	2.0.30
  SuSE 5.1	2.0.32
  SuSE 5.2
  SuSE 5.3	2.0.35
  SuSE 6.0	2.0.36
  SuSE 6.1	2.2.5 (Apr 99)
  SuSE 6.2	2.2.10 (Aug 99)
  SuSE 6.3	2.2.13 (Dec 99)
  SuSE 6.4	2.2.14 (Apr 00)
  SuSE 7.0	2.2.16 / 2.4.0_test1
  SuSE 7.0 s/390	2.2.16
  SuSE 7.1	2.2.18 / 2.4.0
  SuSE 7.2	2.4.4-17
  SuSE 7.3	2.4.10
  SuSE 8.0	2.4.18 (Apr 02)	KDE 3.0, Apache 1.3.23, Samba 2.2.3
  SuSE 8.1	2.4.19 (Oct 02)	gcc 3.2, KDE 3.0.3, GNOME 2.0, Apache 2.0.40, Samba 2.2.5, ext3, USB 2.0, WEP
  SuSE 8.2	2.4.20 (Mar 03)
  SuSE 9.0	2.4.21 (Sep 03)
  SLES 9	2.6	SUSE Linux Enterprise Server
  SuSE n.n	2.6.nn (mes 0n)	BlueZ (Bluetooth protocol stack)

  Linux HQ kernel
  The current Linux kernel versions are here (helsinki), and also kernel version numbering scheme. The also hold Linux FAQs and LDP ! Remember :
  Versions r.x.y, where x is an even number, are stable versions, and only bug fixes will be applied as y is incremented. So from version 2.0.2 to 2.0.3, there were only bug fixes, and no new features. Versions r.x.y, where x is an odd number, are beta-quality releases for developers only, and may be unstable and may crash, and are having new features added to them all the time.
  
  For Red Hat names, look here. And old releases here.
  Few distributions have their kernels are listed here.

• URL últimas versiones : Kernel / intranet

• Links distribucions :

  • Caldera
  • Debian
  • Knoppix - Linux Live CD. Usar "knx-hdinstall" desde consola root
  • Linex
  • Mandarke
  • Red Hat
  • TurboLinux
  • Ubuntu - Debian based - (Hoary Hedgehog, Breezy Badger, Dapper Drake) - funded by the South African internet multimillionaire and occasional cosmonaut Mark Shuttleworth. Article

    Sites :

    • Guia oficial
    • Live CD [*] download, releases : 6.06.2 LTS (Dapper Drake), 6.10 (Edgy Eft), 7.04 (Feisty Fawn), 7.10 (Gutsy Gibbon), 8.04.1 LTS (Hardy Heron).
    • Re-Mastering; Keeping your LiveCD settings to a USB stick : LiveCDPersistence.
    • Ivan
    • Notes

    What happened to Live CD ?
    While Ubuntu 5.10 (Breezy Badger) had a Live CD (an Ubuntu CD that runs directly off your Memory and the Disc, without installing anything to hard-disk) and an Install CD, Ubuntu 6.06 'Dapper Drake' and later versions have a "Desktop" and an "Alternate" CD. The Desktop CD contains a Live session with an installer, once started up; it does not have the classical text installer. The Alternate CD has the old text-installer, with no Live session available.

  Un lloc que mesura les distribucions, etc : DistroWatch.

Top

In the PS1 environment variable, you can directly execute any Linux command, by specifying in the format $(linux_command) :

url, "bask cookbook" by Carl Albing, JP Vossen and Cameron Newham ; pdf

server fault, stack overflow

Top

{20211210} no puc fer SCP de R3 a Mars ni al inreves.

Configurem :

... and restart FTP server :

Use SSH !

FTP server (wu-ftpd) is no longer available with xinetd. It has been replaced with vsftp and can be started from /etc/init.d/vsftpd as in the following:

If you want the vsftpd service to start and stop when recycling (rebooting) the machine, you can create the following symbolic links:

If FTP into your machine fails after a large timeout (client sees connected, but not FTP server ready), you have a problem with /etc/resolv.conf. Thanks again, Albert.

If /var/log/secure contains

FTP service is controlled from the /etc/inetd.conf file. The line looks like

... and is automatically invoked whenever someone connects to the FTP port. Ports are logical associations from a network connection to a specific service. See the /etc/services file for the complete list. FTP uses port 21. When a connection is detected, the FTP daemon /usr/sbin/in.ftpd is invoked and the session begins. Before you are asked for a user, ftpd is started.
The ftpdaemons (a wu) are initiated as root (try opening an ftp connection from command prompt) before you log-in, the process will be running as root, but as soon as you log-in as a user, the ftpd will be suexeced to your username. You can easily monitor the process with ps aux | grep ftp[d] and see how it happens.
/etc/ftphosts file which lists hosts that *are not* allowed to use ftp.
/etc/ftpusers file which lists users that *are not* allowed to use ftp.
All ftpd files come from wu-ftpd package (RH 6.2).

Top

SELinux (Security Enhanced Linux) is a mandatory access control security mechanism implemented in the 2.6 kernel, and has two major components on your system.
There's the kernel mechanism which is enforcing a bunch of access rules which apply to processes and files.
And secondly, there's file labels.
Every file on your system has extra labels attached to it which tie-in with those access rules. Run ls -Z and you'll see what I mean.

To disable SELinux, edit /etc/selinux/config and change the SELINUX line to SELINUX=disabled

disable selinux

Top

Usual install tool is yast, but yum is very interesting too !

Services : chkconfig

See configuration in /etc/yum.conf and directory /etc/yum.repos.d/ (rh-64b)

To display the current values of global yum options, that is, the options specified in the [main] section of the /etc/yum.conf file, run

Yum repositories commonly provide their own .repo file. To add such a repository to your system and enable it, run the following command as root:

For MQTT :

For mongo-db :

Repos we have:

Before next command, run as root

• yum clean all
• yum install mongo-10gen mongo-10gen-server

url

An interesting sequence:

URL

1. define dvd
   cat /etc/fstab /dev/dvd /media udf,iso9660 noauto,user,ro 0 0

2. mount dvd
   mount /media

3. setup repository - to get yum use the DVD as a repository, add a file rhel-dvd.repo in /etc/yum.repos.d with the following content:
   [dvd] name=Red Hat Enterprise Linux Installation DVD baseurl=file:///media/Server enabled=0 gpgcheck=0 // dont verify signatures

4. use new repos
   # yum install --enablerepo=dvd packagename

   Sample

   # yum provides --enablerepo=dvd */uuencode Loaded plugins: product-id, security, subscription-manager Updating Red Hat repositories. sharutils-4.6.1-2.x86_64 : The GNU shar utilities for packaging and unpackaging shell archives. Repo : dvd Matched from: Filename : /usr/bin/uuencode

   This shows the package sharutils contains a file /usr/bin/uuencode

15 yum commands

The magic word in the X window system is DISPLAY. A display consists (simplified) of:

• a keyboard
• a mouse
• and a screen

A display is managed by a server program, known as an X server. The server serves displaying capabilities to other programs that connect to it.

The remote server knows where it have to redirect the X network traffic via the definition of the DISPLAY environment variable which generally points to an X Display server located on your local computer.

The value of the display environment variable is "hostname:D.S", where:

• hostname is the name of the computer where the X server runs. An omitted hostname means the localhost.
• D is a sequence number (usually 0). It can be varied if there are multiple displays connected to one computer.
• S is the screen number. A display can actually have multiple screens. Usually there's only one screen though where 0 is the default.

Configuració : system-config-packages - requires $DISPLAY !

New User : useradd + passwd. See /home/<user>/ directory is created.

"xterm -x" or (putty) Connection -> SSH -> X11 : "Enable X11 forwarding"

RPM based distributions (RHEL, Fedora Core, Cent OS, Suse Linux etc) - use rpm command to get list of all installed software:

To install all software:

url

documentacio

To run it daily:

Or :

To read config file :

The default MDA on Red Hat Linux systems is procmail. Postfix Installation on RH, and how to remove "sendmail" :

If you have local access (as wget) but not remote, then stop firewall using:

• chkconfig --list | grep iptables
• service iptables stop
• chkconfig iptables off

Aux commands:

• service iptables status
• chkconfig iptables
• chkconfig iptables on
• service iptables start
• systemctl status iptables.service
• journalctl -xn
• netstat -lnp | grep service name

Hostname & Default Gateway: edit /etc/sysconfig/network file to set HOSTNAME=thename and GATEWAY=<ip>.

DNS and Domain: edit /etc/resolv.conf file to set NAMESERVER=thename and DOMAIN=thename.

The most important option in resolv.conf is nameserver, which gives the IP-address of a name server to use. If you specify several name servers by giving the nameserver option several times, they are tried in the order given.

Two other options, domain and search deal with default domains that are tacked onto a hostname if BIND fails to resolve it with the first query. The search option specifies a list of domain names to be tried, separated by spaces or tabs. If no search option is given, a default search list is constructed from the local domain name by using the domain name itself, plus all parent domains up to the root. The local domain name may be given using the domain statement.

IP por DHCP :

IP fixe o estàtica :

Amb Network Manager (manage using nmcli) :

No controlem el nom que fa servir:

Network Manager - rh docu.
Disable it :

DHCP client:

Visualitzem el default Gateway amb:

I les dades del DHCP amb:

IP estàtica:

Display all IP data {with a parse pending...} :

Display own IP:

Use conky + "${addr eth0}"

Network restart :

xInetd :

ifdown/up :

url

yum install samba & vi /etc/samba/smb.conf
Creer le share public

Alors

Et voila!

Use Remote VNC at Windows, and configure access at RH via System -> Preferences -> Remote desktop (remove "Ask for your confirmation").
Descripcio. Read RedHat. Download.

Hi tenim el DVD per instalar RPMs :

rpmfind

Verificar si ja hi es instalat:

El instalem :

In Red Hat Enterprise Linux, vsftpd only allows anonymous users to log in by default. To allow authenticated users to log in, edit /etc/vsftpd/vsftpd.conf as the root user. Make sure the local_enable=YES option is uncommented:

Run "service vsftpd start" as the root user to start vsftpd. If the service was running before editing vsftpd.conf, run "service vsftpd restart" as the root user to apply the configuration changes:

uDev & IP's & MAC's:

SLES 11 firewall :

Fem

Comandes service & chkconfig : url

Redhat 9 comes with the ftp server vsftpd. This is installed by default, but does not run at boot up.
To run vsftpd type:

Restart:

To run vsftpd at bootup type, edit /etc/rc.local to insert a line like :

Verification - run "ftp localhost" as the user you are currently logged in with. When prompted for your name, make sure your username is displayed. If the correct username is displayed, press Enter, otherwise, enter the correct username

En el nostre cas

Read test wiki {internal}

See your system https://surprise.raleigh.ibm.com/rhn/

• configure RHEL : # wget -qO- --no-check-certificate https://surprise.raleigh.hal.com/pub/bootstrap/bootstrap.sh | /bin/bash
• register to the new RHN satellite : # rhnreg_ks --force --username=user@<country-code>.hal.com --password=your_ftp3_passwd
• system update : yum update {large !}
• package install : yum install gcc apr httpd
• package removal : yum remove pidgin
• find your system on RHN : https://surprise.raleigh.ibm.com/rhn/Login.do; + FTP3 credentials

vesoares@linux.hal.com

Top

Configure (command line) using yast from root. SLES 10 Install & Admin doc.

Interesting files for troubleshooting :

An interesting file executed at end /etc/init.d/halt.local :

Admin Guide. Forum Novell.

/etc/init.d/before.local = user defined resource control script which should be executed _before_ runlevel is entered.
/etc/init.d/after.local = user defined resource control script which should be executed _after_ runlevel is entered.

Download (FTP3) : /suse/release_cds/sles-10-ppc - Power PC.

To have a graphical envir into P9111, do :

1. on T400, edit X0.hosts to include p9111's IP.
2. on T400, start Xming (a small icon appears in tray area).
3. on p9111, do export DISPLAY="<T400.IP>:0"
4. on p9111 now you launch the command "xeyes &" and "xterm &" and SaX2 & (under root) ... but the window shall open on T400 desktop !

Nowell documentation.

Configurador / instalador / updater (!) : "yast". GUI Control Center : "yast2".

Instalador : zypper

Servicios : chkconfig

SuSEconfig - configure system from variables set in /etc/sysconfig/ files

SuSE (auto) Yast : /root/autoinst.xml

/root/autoyast.xml

/var/adm/autoinstall/cache

Cloned SUSE 11 virtual machine does not have network connectivity after reboot.

zypper manual, another by SuSE

List repositories:

Global configuration file : /etc/zypp/zypp.conf

Directory containing repository definition : /etc/zypp/repos.d

Search for packages/repositories

. . . pending . . .

Quin port fan servir ? By default BIND listen DNS queries on port 53

Required packages :

• DHCP : dhcp-server
• DNS : bind

SolutionBase: Configuring a DHCP server with SuSE's YaST ; Configuring a DNS server with SuSE's YaST ;

DNS & SLES.

In file /etc/sysconfig/network/config, set

Hostname : edit /etc/HOSTNAME (mind UpperCase) file to set the_name.

Static IP : edit /etc/sysconfig/network/ifcfg-eth<id> to set IPADDR='1.2.3.4' and BOOTPROTO=static

Dynamic IP :

Default Gateway :

To display it, use:

To restart communications (the ones that have "ONBOOT=yes" in ifcfg-ethx), use

DNS & domain :

DNS cfg : /etc/named.conf + 1 text file by zone

DHCP cfg :(port 67)

To use a USB disc on SuSE, do :

• connect the USB disc to SuSE system
• tail -f /var/log/messages for device, as sdb: sdb1
• mkdir /tmp/USB
• mount /dev/sdb1 /tmp/USB

Edit "/etc/ssh/sshd_config". Scroll down until you find "PermitRootLogin" and change it to PermitRootLogin no.

Reload the SSH server config using /etc/init.d/sshd reload

VSFTPD url, doc.

Standalone : edit /etc/vsftpd.conf, and verify:

Start FTP daemon manually:

If we want to run FTP daemon from xinetd, then

a) remove "LISTEN=YES from /etc/vsftpd.conf :

b) then, verify /etc/xinetd.conf :

c) create ftp in /etc/xinetd.d and observe /var/log/xinetd.log:

Restart xinetd using /etc/init.d/xinetd restart and try ftp localhost.

De nou, la magnifica url

Configure

Verify remote access:

Per instalar Filezilla a SuSE 10, fem :

• anar a SuSE Search + select "SuSE SLE 10" + posar "Filezilla" -> baixar FileZilla-3.1.0.1-4.1.i586.rpm
• rpm -ivh FileZilla-3.1.0.1-4.1.i586
• Filezilla available at "Computer" + "Favorite Applications / More Applications"

Based on www.server-world.info :

Install :

How to install MySQL through YaST

See here to know how to fix it. Then :

Details on usual operations can be found here

Detailed apache mysql page

• how to reset lost root password on SLES

Top

Wiki

Community

Ubuntu Guide

Ubuntu Geek

Instalació VMWare Server, 8.04

• Ubuntu 9.04 @ RAP
• Ubuntu 12.04 LTS @ 6Q
• Ubuntu 14.04 LTS @ T60 {20160111}
• Ubuntu 16.04 LTS @ T60 {20181007}
• 20180907 says 18.04 available - requirements :
  • 2 GHz dual core processor : T1300 1,66 Ghz {sudo lshw | grep -i cpu} {cat /proc/cpuinfo} {lscpu}
  • 2 GB system memory : 3,018 GB {cat /proc/meminfo}
  • 25 GB of free hard drive space
  
  20190204 - I install Bionic Beaver on T60
• 2020 : 18.04 on MARS

Tenim un portatil vell HP Pavilio ZD7000, harman/kardon (F10 to enter BIOS)

• CPU : Intel Pentium 4 a 3,06 GHz
  Instruction set : 32-bit
• RAM 512 MB
  use Xubuntu or Lubuntu

Hi volem posar un Ubuntu i fem :

1. on PC, we get LTS 16.04.5 Server (32-bit) : 874.512.384 ubuntu-16.04.5-server-i386.iso
2. we get an old 8 GB pen drive
3. on PC, we install win32 disk imager
4. on PC, we write Image File to Device
5. al portatil, revisem la BIOS per admetre botar des USB
6. al portatil botem Ubuntu Server des el USB i l'instalem al disc dur si ens agrada

Tambe tinc un USB amb Lubuntu 18.04 LTS 32-bit ! 749.731.840 lubuntu-18.04-alternate-i386.iso

No sap botar de USB -> comprem Raspberry !

Ubuntu doc : system-wide values are set in /etc/environment :

Logging out and back in would apply the changes ...

Can set some in /etc/profile, as url indicates :

• whoopsie & how to remove it

• gio (part of glib2) - gio is a utility that makes many of the GIO features available from the commandline
  sebas@minie:~$ gio version 2.72.4 sebas@minie:~$ gio help trash Usage: gio trash [OPTION…] [LOCATION…] Move/Restore files or directories to the trash. Options: -f, --force Ignore nonexistent files, never prompt --empty Empty the trash --list List files in the trash with their original locations --restore Restore a file from trash to its original location (possibly recreating the directory)

• xdg-mime - command line tool for querying information about file type handling and adding descriptions for new file types
  nicolau@mars:~$ xdg-mime query default x-scheme-handler/magnet smartcode-stremio.desktop
  nicolau@nicolau-desktop:~$ gio mime x-scheme-handler/magnet Default application for “x-scheme-handler/magnet”: smartcode-stremio.desktop

  how to change from "stremio" to "transmission" ?

  1. download "any" torrent file, as "nobody.torrent"
  2. go to the file (probably nom/Downloads/torrents)
  3. right-click on the file
  4. select "open with another application"

  If we are using Opera :

  1. make sure you are NOT running the snap version of Opera, because snap apps do not have access to the system's associations for protocols like magnet://, mailto://, tel:// and so on.
     If so, uninstall it and install the deb version of it.
  2. top-right, open "Easy Setup"
  3. activate "Show Sidebar"
  4. on sidebar on the left, click on "Settings"

  forums opera

  xdg-mime default transmission-gtk.desktop x-scheme-handler/magnet --- set Transmission xdg-mime default deluge.desktop x-scheme-handler/magnet --- set Deluge xdg-mime default qBittorrent.desktop x-scheme-handler/magnet --- set qBittorrent

  ask ubuntu

  Done on MARS

  nicolau@mars:~$ xdg-mime default transmission-gtk.desktop x-scheme-handler/magnet nicolau@mars:~$ xdg-mime query default x-scheme-handler/magnet transmission-gtk.desktop nicolau@mars:~$ gio mime x-scheme-handler/magnet Default application for “x-scheme-handler/magnet”: transmission-gtk.desktop

  Test your magnet association : *** magnet test ***

• System Monitor :
  • gnome-system-monitor GUI Task Manager
  • htop { "htop -u sebas" to display only my processes - or press 'u' key to select a user }

• "Print Screen" goes to "Pictures" directory with a timestamp ...

  Screenshot locations (not in 18.04)

  nicolau@mars:~/.config$ cat user-dirs.dirs # This file is written by xdg-user-dirs-update # If you want to change or add directories, just edit the line you're # interested in. All local changes will be retained on the next run. # Format is XDG_xxx_DIR="$HOME/yyy", where yyy is a shell-escaped # homedir-relative path, or XDG_xxx_DIR="/yyy", where /yyy is an # absolute path. No other format is supported. # XDG_DESKTOP_DIR="$HOME/Desktop" XDG_DOWNLOAD_DIR="$HOME/Downloads" XDG_TEMPLATES_DIR="$HOME/Templates" XDG_PUBLICSHARE_DIR="$HOME/Public" XDG_DOCUMENTS_DIR="$HOME/Documents" XDG_MUSIC_DIR="$HOME/Music" XDG_PICTURES_DIR="$HOME/" -> add Pictures or "scsh" XDG_VIDEOS_DIR="$HOME/Videos"

  Test function is available using "gnome-screenshot" url
  Then assign "Save screenshot to SCSH directory" to a key using "Settings" + "Devices" + "Keyboard"

Edit the line in /usr/share/applications/smartcode-stremio.desktop

reddit

Reboot computer {MARS 20211030}

MARS :

1. sudo mkdir /etc/lightdm/lightdm.conf.d

2. sudo nano /etc/lightdm/lightdm.conf.d/50-myconfig.conf
   [SeatDefaults] autologin-user=USERNAME

Push the "Super" key, also "Windows" key

Has a nice log in /var/log/apt/history.log and terminal output with any warning messages in term.log - askubuntu

What is initramfs ?

Dangerous command : update-initramfs

Select "Resources" for a nice graph

The shell program /bin/bash uses a collection of startup files to help create an environment.

An interactive login shell is started after a successful login, using /bin/login, by reading the /etc/passwd file. This shell invocation normally reads /etc/profile and its private equivalent ~/.bash_profile upon startup.

The file ~/.bash_logout is read and executed when a user exits from an interactive login shell.

url [*****]

An interactive non-login shell is normally started at the command-line using a shell program (e.g., [prompt]$/bin/bash) or by the /bin/su command. An interactive non-login shell is also started with a terminal program such as xterm or konsole from within a graphical environment.
This type of shell invocation normally copies the parent environment and then reads the user's ~/.bashrc file for additional startup configuration instructions.

A non-interactive shell is usually present when a shell script is running. It is non-interactive because it is processing a script and not waiting for user input between commands. For these shell invocations, only the environment inherited from the parent shell is used.

• login shells execute ~/.profile, which executes ~/.bashrc (unless you remove the linking from .profile yourself)
• non-login shells will only execute ~/.bashrc

Every shell where you type your user name & password to log in is a login shell.

url

How to remove it ?

On MARS I find

I la comanda sorprenent és

Tampoc esta malament eixa :

Eixa es la eina :

It means you got more software installed from containers. Each loop device is a snap install.

Snap is a software deployment and package management system.

/dev/loop* are loop devices making plain files accessible as block devices.

Loop Device files are used to make a block device to access regular files.

Bottom-line: by using Snaps for having up-to-date software, we end up paying for it with higher network traffic, more disk usage and slower boot time. If you do not want to use Snaps at all, then remove them with sudo apt-get purge snapd, or better disable it !

Available commands :

Display version :

Nice snap use page

On MARS, trash icon is gone as 20201019

First, locate all the Trash folders :

our trash on ext3 partitions should be in ~/.local/share/Trash/Files

Open Gnome configuration editor (Alt+F2, "gconf-editor"), go to the section /apps/nautilus/desktop and enable the "Trash_icon_visible" checkbox - I dont have "Nautilius"

Launch Tweaks, go to "Desktop" and select what icons you want on the desktop - I set "trash" to "on" but it does not come up.

Launch "sudo dconf-editor", go to "/org/gnome/nautilus/desktop" and set "trash-icon-visible = ON" - the same

Using "gsettings"

GUI : "System -> Administration -> Update Manager"

Command line (see "apt-get help") or apt-get howto, apt's diferencies, (en)

Typical :

Un error curios :

Solució (url)

Una mica de detall : url

• sudo apt-get update

  apt-get upgrade actually installs newer versions of the packages you have. After updating the lists, the package manager knows about available updates for the software you have installed. This is why you first want to update.

• sudo apt-get dist-upgrade

  apt-get dist-upgrade, in addition to performing the function of apt-get upgrade, also intelligently handles changing dependencies with new versions of packages and will attempt to upgrade the most important packages at the expense of less important ones if necessary. Thus, the apt-get dist-upgrade command may actually remove some packages in rare but necessary instances.

Actions of the apt-get command are logged in the /var/log/dpkg.log log file.

An interesting message :

If dpkg is interrupted, you need to run

Download Ubuntu.

Installing VMware Player or Server [***] on Ubuntu
Has patch + shell !

Activate Telnet.

Install SSH. Doc (gracias, Bruno !)

Verify it works :

Install sendemail (in debian lenny) :

Using askubuntu :

We do

python 3.7 apparently broke "sudo apt-get update" - superuser

The commands are :

remove is identical to install except that packages are removed instead of installed. Note that removing a package leaves its configuration files on the system.

purge is identical to remove except that packages are removed and purged (any configuration files are deleted too).

diferencies

• check which desktop environment you are using
  nicolau@mars:~$ echo $XDG_CURRENT_DESKTOP ubuntu:GNOME

• remove MATE :

  I got a problem : cant open a desktop folder :

  nicolau@mars:/usr/share/dbus-1/services$ slog Jun 5 19:26:11 mars nautilus-deskto[4775]: cannot open folder on desktop, freedesktop bus not ready

  Remove service from dbus :

  sudo rm -f /usr/share/dbus-1/services/org.mate.freedesktop.FileManager1.service

  Remove package :

  sudo apt-get remove mate-desktop sudo apt-get remove --auto-remove mate-desktop sudo apt-get purge mate-desktop sudo apt-get purge --auto-remove mate-desktop

url

I want it to start "full screen" (as F11)

What's the difference between full screen and maximized ?

Ubuntu uses apt for package management. APT stores a list of repositories or software channels in the file

... and in any file with the suffix .list under the directory

In the "sources.list.d" we have all PPA , Personal Package Archive

Use

• hit "Windows" key - it opens "Unity Dash"
• search for "Software Sources"

Display Ubuntu release current version you have :

Remember to retrieve updated package lists by issuing a sudo apt-get update when you're done editing sources.list.

help ubuntu repositories

Missatge de error "i386 not supported" :

Networking configuration using command line :

• /etc/network/interfaces [***] - good doc, with commands as "sudo lshw -class network" and "sudo ethtool eth0", and "/etc/udev/rules.d/70-persistent-net.rules" description
  • loopback interface - by default, there should be two lines in /etc/network/interfaces responsible for automatically configuring your loopback interface. It is recommended that you keep the default setting.
    auto lo iface lo inet loopback

  • DHCP :
    auto eth0 iface eth0 inet dhcp

  • static IP :
    sebas@T60ubuntu:/etc/network$ cat interfaces auto eth0 iface eth0 inet static address 192.168.1.60 netmask 255.255.255.0 gateway 192.168.1.1 dns-nameservers 8.8.8.8 8.8.4.4

    Another

    auto eth0 iface eth0 inet static address 10.0.0.100 netmask 255.255.255.0 gateway 10.0.0.1 network 10.0.0.0 broadcast 10.0.0.255

  • second IP :
    auto eth0:1 iface eth0:1 inet static address 192.168.1.60 netmask 255.255.255.0

• default gateway :

  To set it :

  mate@punt-omnia:~$ cat /etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). source /etc/network/interfaces.d/* # The loopback network interface auto lo iface lo inet loopback # LAN Interface (and Gateway) auto enp4s0 iface enp4s0 inet static address 192.168.1.254 netmask 255.255.255.0 broadcast 192.168.1.255 network 192.168.1.0 gateway 192.168.1.1 dns-nameservers 8.8.8.8 8.8.4.4 post-up iptables-restore < /etc/iptables.up.rules

  display default gateway :

  guifi@torrelles:~$ route -n {from 10.139.130.34} Tabla de rutas IP del núcleo Destino Pasarela Genmask Indic Métric Ref Uso Interfaz 0.0.0.0 10.139.130.33 0.0.0.0 UG 0 0 0 eth0 10.139.130.32 0.0.0.0 255.255.255.224 U 0 0 0 eth0

  Again, more explicit :

  guifi@torrelles:~$ route Tabla de rutas IP del núcleo Destino Pasarela Genmask Indic Métric Ref Uso Interfaz default 10.139.130.33 0.0.0.0 UG 0 0 0 eth0 10.139.130.32 * 255.255.255.224 U 0 0 0 eth0

  Another command :

  guifi@torrelles:~$ ip route show default via 10.139.130.33 dev eth0 10.139.130.32/27 dev eth0 proto kernel scope link src 10.139.130.34

• restart networking : sudo /etc/init.d/networking restart
  Or "sudo ifdown -a" + "sudo ifup -a"

• set hostname : sudo vi /etc/hostname

• DNS : edit /etc/hosts for static lookups

• DNS : edit /etc/resolv.conf to provide server

• proxy - to set it system-wide, edit /etc/environment to include
  http_proxy=http://192.168.43.100:3128/ https_proxy=https://192.168.43.100:3128/

help ubuntu tcpip

Comanda per agafar IP del DHCP : sudo dhclient
Comanda per ficar IP fixe : sudo ifconfig eth0 192.168.3.4 netmask 255.255.255.0 up {NO sobreviu a restart}
Ubuntu & Default GW : sudo ip route add default via 192.168.1.254
To register to DNS : in /etc/dhcp3/dhclient.conf set send host-name "<my_hostname>"; : the hostname needs to be updated in DNS (to use nslookup)

Display local open ports :

Install server by :

1. create /etc/ssh/my_banner.txt with desired text
2. modify /etc/ssh/sshd_config to contain "Banner /etc/ssh/my_banner.txt"
3. restart sshd service by "sudo service sshd restart"
4. test "ssh user@ip" to see welcome message before entering the password, but after the user

Run the ssh command in "triple verbose" mode:

This will show you diagnostic messages from the ssh command.

You can also tail /var/log/messages and /var/log/secure on the r0 server as you are trying the ssh command.

• ifconfig -a
• iwconfig wlan0 essid name key password

Got "failed to download package files" message

1. press "Alt+F2" and type software-properties-gtk
2. change the download location to Main Server
3. run sudo apt-get update again

fix

The main directory is /var/lib/apt/lists/ (including "partial" sub-dir)

Very interesting Package Manager troubleshooting procedure :

Ubuntu 18.04 uses netplan instead of /etc/network/interfaces.
netplan gives a central location to describe simple to complex networking configurations

We do (url)

1. Install :
   1. sudo apt remove ifupdown
   2. sudo apt-get update -y
   3. sudo apt-get install -y netplan.io
   4. echo "ENABLED=1" | sudo tee /etc/default/netplan

2. configuration file : .yaml under /etc/netplan, as /etc/netplan/config.yaml

3. see network interface cards :
   $ ip a

4. configure local network :
   $ cat /etc/netplan/10_local_net.yaml # sebas 20200521 network: version: 2 renderer: NetworkManager ethernets: eth0: addresses: [192.168.1.60/24] gateway4: 192.168.1.1 nameservers: addresses: [8.8.8.8,8.8.4.4] dhcp4: no wlan0: addresses: [192.168.1.121/24]

5. sudo netplan generate = validate the configuration, as for invalid IP range

6. sudo netplan try = revert in 120 seconds

7. sudo netplan apply

8. verify we have correct gateway :
   $ route -n

9. verify the DNS is correct :
   $ systemd-resolve --status eth0

10. bring interfaces up or down - dont use "ifconfig" or "ifup" nor "ifdown"
    $ ip link set eth0 up $ ip link set wlan0 down

11. deconfigure an interface : remove from the .yaml file and run "sudo netplan apply"

netplan FAQs, reference

If network status displays a "question mark" even it is working, it means the internal connectivity test fails.

This new feature works by pinging the http://connectivity-check.ubuntu.com URL, time to time, in order to detect a captive portal.

It is managed by "Settings" + "Privacy" : "Connectivity Checking" on/off

Have a look at

While trying to access Wifi facility at coffee shops, airports, business centers, hotel lobbies, etc, we find ourselves landing on a webpage that asks for authentication, payment, and/or acceptance of terms of the agreement. Only when we provide the required information are we able to access the Wifi facility. The Login page of this sort is called a Captive Portal. Before Ubuntu 17.10, the Ubuntu server was not too good with connecting to these Captive portals so a Connectivity Checking feature was introduced - url

nmcli -

nmtui - Text User Interface for controlling NetworkManager

nmcli commands I use are :

• to see list of saved connections, use (<SavedWiFiConn>) : nmcli c
• to see list of interfaces (<WifiInterface>) : ifconfig -a

Example of a typical configuration of /etc/resolv.conf for a server on the domain "example.com" and using two public DNS servers.

The search option can also be used with multiple domain names so that DNS queries will be appended in the order in which they are entered. If you have multiple domains you wish to search, your configuration might look like the following.

If you try to ping a host with the name of server1, your system will automatically query DNS for its Fully Qualified Domain Name (FQDN) in the following order:

If no matches are found, the DNS server will provide a result of notfound and the DNS query will fail.

url

To add a link to the left pane, go to the desired directory and hit "CTRL" + "D"

Tinc un parell de webcam de la marca "Logitech", una vermella i una grisa, "QuickCam Messenger", model UBC40

• grisa :
  • P/N = 860-000049, part number
  • M/N = V-UBC40, model number
  • windows drivers

Bon tutorial

• Find PN i MN : support.logi.com - etiqueta al final del fil, vora USB

• Find software : support.logi.com

• Logitech webcam support in Ubuntu :
  USB id : 046d:08da ; driver : spca5xx ;
  Gutsy: works out of the box with amsn.
  Edgy: requires updated spca5xx driver, easy to get with module-assistant. Only works with amsn or luvcview not ekiga or camorama or gqcam

• skype :
  driver : gspca ; Works but without internal microphone.
  Switch to an external microphone.

We have to have :

Llocs per provar si funciona :

• https://webcammictest.com/
• https://www.onlinemictest.com/webcam-test/

• start VLC
• choose 'Open capture device' from the "Media" menu
• set "Video device name" to "/dev/video0"
• click "Play" - you must see a video

But cheese does not work :

What is guvcview ?

Ubuntu gnome howto

Open gnome settings by

1. "Show Applications"
2. (gnome) "Tweaks"

go there and click "CTRL" + "D"

askubuntu

You can control how the file manager displays captions under icons.

Click the menu button in the top-right corner of the window and select Preferences, then select the Views tab.

... or, ... click Files in the top bar, pick Preferences and select the "Display" tab.

help gnome

Using "Files" app, display/hide files starting with . or end with ~ using "CTRL" + "H"

super user

1. install and start dconf
2. Change icon size in icon view: “org/gnome/nautilus/icon-view/default-zoom-level”
3. Change icon size in list view: “org/gnome/nautilus/list-view/default-zoom-level”

handbook

ST tricks

Compte : el ST detecta que es un fitxer python, pero posa TAB en el lloc de 4xSB !

1. Update the apt package list and install the dependencies necessary to fetch packages from https sources:
   sudo apt update sudo apt install apt-transport-https ca-certificates curl software-properties-common

2. Import the repository’s GPG key using one of the following commands:
   curl -fsSL https://download.sublimetext.com/sublimehq-pub.gpg | sudo apt-key add - wget -qO - https://download.sublimetext.com/sublimehq-pub.gpg | sudo apt-key add - Key is stored in legacy trusted.gpg keyring (/etc/apt/trusted.gpg) wget -qO- https://myrepo.example/myrepo.asc | sudo tee /etc/apt/trusted.gpg.d/myrepo.asc wget -qO - https://download.sublimetext.com/sublimehq-pub.gpg | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/sublimehq-archive.gpg > /dev/null # correct way ! sebas@minie:~$ sudo apt-get update Reading package lists... Done

3. Add the Sublime Text APT repository to your system’s software repository list by typing:
   $ sudo add-apt-repository "deb https://download.sublimetext.com/ apt/stable/" # old way $ echo "deb https://download.sublimetext.com/ apt/stable/" | sudo tee /etc/apt/sources.list.d/sublime-text.list # new way

4. Once the repository is enabled, update apt sources and install Sublime Text 3 with the following commands:
   sebas@minie:~$ sudo apt-get update sudo apt install sublime-text

5. That’s it.

linuxize

If it’s asking you for a license key, you’re trying to run a development build.

Verify it is installed :

To remove SublimeText and reinstall it:

1. download sublime_text_build_4121_x64.tar.xz from https://www.sublimetext.com/download

2. extract
   nicolau@mars:~/eines/ST$ ls -al /home/nicolau/Downloads/su* nicolau@mars:~/eines/ST$ tar -tf /home/nicolau/Downloads/sublime_text_build_4121_x64.tar.xz nicolau@mars:~/eines/ST$ tar -xvf /home/nicolau/Downloads/sublime_text_build_4121_x64.tar.xz sebas@minie:~/eines/ST$ tar -xvf /home/sebas/Downloads/sublime_text_build_4189_x64.tar.xz

3. restart editor

You record a macro, but it stays in memory until "Tools" + "Save macro" write it into a file into directory /home/nicolau/.config/sublime-text-3/Packages/User

You assing it a key-shortcut using "Preferences → Key Bindings - User"

It crashes with "segfault" at libc-2.31.so if installed from snap

stackOverflow

1. sudo add-apt-repository ppa:pi-rho/security
2. sudo apt-get update
3. sudo apt-get install wireshark
4. usermod -a -G wireshark <your user>
5. newgrp
6. sudo wireshark &

Read docs

url :

Zeitgeist is a service which logs the users’s activities and events, anywhere from files opened to websites visited and conversations.

Display packages on the system :

Remove packages :

To select what App to use to view a video, do :

1. find the video file using "Files"
2. right-click and select "Properties"
3. select "Open with" and choose al App
4. select "set as Default"

The desktop has 3 main parts :

• Main Desktop
• Unity Launcher
• Top Menubar

Display complete clock :

• use gsettings set org.gnome.desktop.interface clock-show-date true

  url or install dconf

• use Gnome shell extension clock override

Mind the format of the timestamp - use Tweaks !

Follow these steps :

1. press "Alt"+"F2" to get "Enter a Command" prompt
2. type dconf-editor to start settings editing interface
3. go to org -> gnome -> gnome-screenshot
4. enter the path to your folder

Via command line :

url

1. start it, as /usr/bin/firefox
2. on the run-time icon, click right button
3. select "Lock to Launcher"

Install details

ask ubuntu :

Real VNC viewer

• enable vino : gsettings set org.gnome.Vino enabled true
• gsettings set org.gnome.Vino prompt-enabled false
• gsettings set org.gnome.Vino require-encryption false
• start vino : export DISPLAY=:0.0 && /usr/lib/vino/vino-server
• see all configs available : gsettings list-keys org.gnome.Vino

url

1. sudo vino-preferences : enable "Allow other users to view your desktop"
2. /usr/lib/vino $ ./vino-server

No se puede establecer una conxion a VNC Server con la configuracion de segurirad que ha seleccionado. Actualice VNC Server a una version mas reciente o seleccione un grado de cifrado menos estricto.

1. install the Ubuntu Desktop environment: sudo apt-get install ubuntu-desktop
2. install XRDP : sudo apt install xrdp
3. add port 3389 to Security Groups
4. start the XRDP Application: sudo /etc/init.d/xrdp start
5. sudo adduser USERNAME sudo + su USERNAME + nano .xsession : gnome-session –session=Ubuntu-2d
6. {win} : mstsc

url

Now from Ubuntu Community () ubuntu 18.04:

url

Tired Ubuntu asks for an Admin password every time ? Tired of using sudo ?

You can modify /etc/sudoers - find the line:

Change it to:

Use this command :

After changing /etc/sudoers to 666, I had to reinstall Linux (on Raspberry)

To make a user a sudoer, use "sudo usermod -a -G sudo <username>"
Dont use "visudo"

• reboot machine - after BIOS, hold shift key to enter GRUB menu
• select 2nd entry, the one with recovery mode in the description to enter recovery menu
• scroll down to root shell - get a root prompt. We have a read-only filesystem.
• mount -rw -o remount / - remount it with write permissions
• set new password : paswd sebas
• reboot to use new usr/pwd

Few steps to include a new disk in an existing Ubuntu :

1. sudo apt-get update - update local software
2. sudo lshw -C memory - display available memory
3. sudo lshw -C disk - display disk info
4. sudo blkid - display block id, used in FSTAB
5. sudo fdisk -l - display visible disks
6. sudo dd if=/dev/zero of=/dev/sda - clear disk
7. sudo apt-get install gparted - install package to create partitions using GUI
8. sudo gparted - run it
9. sudo mkdir /mnt/hdd-80GB - create a mount point in filesystem
10. sudo mount /dev/sbd1 /mnt/hdd-80GB - mount new disk and test it works
11. chown /mnt/hdd-80GB -R sebas.sebas - change ownership
12. cat /etc/mtab - display mount info, to inlcude it in FSTAB
13. sudo vi /etc/fstab - edit FSTAB to include new disk forever
    # old disk, 150GB UUID=42d5af35-d271-4431-b746-c778acc6a37f / ext4 errors=remount-ro 0 1 # swap was on /dev/sda5 during installation UUID=58b10253-3b03-4d8b-80f6-91f2a930f414 none swap sw 0 0 # new disk, 80 GB UUID=d4072bf2-564e-459b-a821-8fccfcce6714 /mnt/hdd-80GB ext4 rw 0 0
14. final status, after reboot
    sebas@T60ubuntu:~$ sudo fdisk -l Disk /dev/sda: 80.0 GB, 80026361856 bytes 255 heads, 63 sectors/track, 9729 cylinders, total 156301488 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000505e8 Device Boot Start End Blocks Id System /dev/sda1 2048 156301311 78149632 83 Linux Disk /dev/sdb: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000dab5f Device Boot Start End Blocks Id System /dev/sdb1 * 2048 310503423 155250688 83 Linux /dev/sdb2 310505470 312580095 1037313 5 Extended /dev/sdb5 310505472 312580095 1037312 82 Linux swap / Solaris

We create a new (extended) partition, create a filesystem, make a directory to mount it, and mount it.

Maybe we want to mount it at system boot, so we edit /etc/fstab:

yolinux

1. insert the USB into v2 plug
2. identify the USB drive : lsblk
3. unmount your USB drive's partition : sudo umount /dev/sdb1
4. erase all of the data on the drive : sudo dd if=/dev/zero of=/dev/sdb bs=4k status=progress && sync
5. create a new partition table : sudo fdisk /dev/sdb
6. press "o" to create an empty partition table
7. press "n" to create a new partition
8. press "w" to write the table and exit
9. view your new partition : lsblk
10. format your new volume as FAT32 : sudo mkfs.vfat /dev/sdb1
11. eject your drive when finished : sudo eject /dev/sdb

url

1. locate the drive, ie: /dev/sdc1, by using sudo fdisk -l
2. umount /dev/sdc1
3. reformat the flash-drive : sudo mkfs -t vfat /dev/sdc1

Lets scan BISC for vulnerabilities and BISC@hal for WAS'es !

Start nessus :

Update plugins:

Configure Nessus [/]:

docu

Last minute : use mutt

Install PostFix, default MTA for Ubuntu.

Here it is (pomnia)

1. insert CD
2. an icon is placed on the desktop, labeled "Audio Disc"
3. right-click on "Audio Disc"
4. select "Open with other applications"
5. select "RhytmBox"

To stop it, just kill the PID :

More in detail, using the following procedure, exactly the same ISO image that was used for burning the CD or DVD can be read from a CD or DVD:

1. Reading the block size and the volume size:
   [root@testserver ~]# isoinfo -d -i /dev/cdrom | grep -i -E 'block size|volume size' Logical block size is: 2048 Volume size is: 327867
2. Running dd with the parameters for block size and volume size, with progress indicator:
   [root@testserver ~]# dd if=/dev/cdrom of=test.iso bs=<block size from above> count=<volume size from above> status=progress

thomas krenn

1. find device name using dmesg
2. create ISO : sebas@T60:/tmp/musica $ dd if=/dev/sr0 of=./compay.iso bs=2048
3. burn ISO :

20200829 - try to use Brasero +

20210119 - K3B works perfect :

1. start k3b
2. select "Tools" + "Copy Medium"
3. insert source CD
4. "Source Meduim" goes "Audio CD"
5. click "Start"
6. maybe you have to kill "gvfsd-cdda" - k3b can do it !

Read audio CD creation

20200708 - tried to use Brasero without success. K3B works at second try.

Fix : url :

intro

Aquest mon és una font de entrepussades :

What is the "i" flag ?

Try changing [ifupdown] managed=false to true in /etc/NetworkManager/nm-system-settings.conf
Restart network manager : sudo /etc/init.d/network-manager restart

url.

Solucio :

• temporal : "~$ sudo rm /var/crash/*"
• service : "~$ sudo service apport status", then "stop"
• forever : disable Apport : itsfoss
  edit "/etc/default/apport" and set "enabled=0"
• "sudo dpkg-reconfigure Plymouth" - askubuntu

vitux

Ubuntu webmin how-to

1. get 18.04 LTS desktop (1,9 GB)
2. using Rufus, copy ISO into USB - url
3. boot USB

Help" + "Create a startup disk"

In this context a startup disk is a USB flash drive from which you can startup and install Ubuntu. The capacity of the USB flash drive must be at least 2 GB. Any data on the USB flash drive will be lost when you create the startup disk. It's assumed that you have downloaded an Ubuntu ISO image.

To create a startup disk from an Ubuntu ISO image:

1. open Startup Disk Creator via the Activities search bar.
2. if the ISO image is in your Download folder and there is just one ISO image, Startup Disk Creator will have selected it, otherwise select the correct ISO image.
3. if your computer has just one USB flash drive, Startup Disk Creator will have selected it, otherwise select the correct drive.
4. click Make Startup Disk.
5. click Yes to confirm. The process should take ten minutes or less.
6. when the "Installation Complete" window opens click Quit.

The network installer lets you install Ubuntu over a network. It includes the minimal set of packages needed to start and the rest of the packages are downloaded over the network. Since only current packages are downloaded, there is no need to upgrade packages immediately after installation.

The network installer is ideal if you have a computer that cannot run the graphical installer, for example, because it does not meet the minimum requirements for the live CD/DVD, or because the computer requires extra configuration before a graphical desktop can be used. The network installer is also useful if you want to install Ubuntu on a large number of computers at once.

1 + 2

wiki , HowTos

Usa una partición FAT16 y puede reconfigurarse con sólo editar un fichero de texto

Para ubicar SYSLINUX en la partición FAT16 de su memoria USB, instale los paquetes syslinux y mtools en su sistema, y escriba

La partición no debe estar montada cuando ejecute SYSLINUX. Este procedimiento escribe un sector de arranque en la partición y crea el fichero ldlinux.sys que contiene el código del gestor de arranque

• open File Manager from command line : nautilus --browser . (alias "fm")

• minimize all windows : CTRL + "windows" + "D"

• open Terminal from desktop (command line, shell) : Ctrl + Alt + T
  Ctrl+L – clear the screen

• Alt+F2 - run console command

• Ctrl+Shift+"drag" = create a link to a file or folder

• switch to a virtual terminal (Ctrl+Alt+F1)

• use "CTRL" + "ALT" + "F3" to go to "terminal 3"
  use "ALT" + "F2" to return to exactly where you were

• CTRL + ALT + BACKSPACE : exit X server

• CTRL + ALT + "+" : change video resolution

• files starting with "." are not displayed by Nautilus, by default, they are "hidden".
  Change this setting by "CTRL" + "H" or select 3 horizontal bars (top right) + check "Show hidden files"

• add a shortcut to a directory on left pane of "Files" : go to sirectory and hit "Ctrl+D"

• Ctrl + Esc = process table
• Ctrl + Tab = switch between desktops
• Alt + Tab = switch between applications
• Alt + F4 = close window
• "lletra" = seleccionar la icona del escriptori de nom que comença amb la lletra
• moure cursor amb el teclat : Shift + Alt + NumLock + "cursors"

Read navigating using keyboard only

En detall :

20231128 - no tinc resposta a comandes del snap :

Solucio : restrart Ubuntu

• las claves SSH son credenciales que se utilizan para que el protocolo SSH (Secure Shell)

• el protocolo SSH utiliza una técnica de criptografía llamada encriptación asimétrica

• el cifrado asimétrico es un sistema que utiliza un par de claves : la clave pública y la privada

• creacion de las claves :
  $ ssh-keygen -t ed25519 -C "kinstauser@kinsta.com"

  este comando genera dos archivos en el directorio que hayas seleccionado (normalmente ~/.ssh):
  la clave pública con la extensión .pub, y la privada sin extensión.

• añadir las claves al agente :
  nicolau@mars:~$ eval `ssh-agent` Agent pid 8180 nicolau@mars:~$ ssh-add ~/.ssh/id_ed25519

• Añadir la clave SSH a la cuenta de GitHub :

• Probar la conexión SSH con un "repo push" :

kinsta

1. generar clau publica :
   nicolau@mars:~$ ssh-keygen Generating public/private rsa key pair. Enter file in which to save the key (/home/nicolau/.ssh/id_rsa): Enter passphrase (empty for no passphrase): Enter same passphrase again: cebas,2023 Your identification has been saved in /home/nicolau/.ssh/id_rsa. Your public key has been saved in /home/nicolau/.ssh/id_rsa.pub. The key fingerprint is: SHA256:3XA3jprF7ZTv9tXvq1cv32Xhy104aOSS2V3yEKiHKAk nicolau@mars The key's randomart image is: +---[RSA 2048]----+ | | | . | | E . o + | | . . o B = + | | o S + B B..| | . @ =.B+| | * = =.@| | o o=@| | .oO@| +----[SHA256]-----+
2. id_rsa es la clave privada, que permanecerá en la máquina local.
   id_rsa.pub es la clave pública, que se tiene que copiar al servidor remoto al que se quiere acceder.
3. moure-la al servidor : email "public_key_string" + "echo public_key_string >> ~/.ssh/authorized_keys"
   nicolau@mars:~$ cat ~/.ssh/id_rsa.pub > public_key_string

Network Configuration

Cremo 7.2 en un CD, en ser prou petit.

Que hi ha ?

Esborrem el Guindows ...

20161004 - en Albert m'explica que el Linux Lite te un bon paquete de Ofimàtica, Libre Office, i en Jordi fa poc em demanava un recanvi pel XP.

Install: to create a bootable Live USB, use Win32DiskImager, and then run it using the (968 MB) ISO
Image file := nom.iso ; Device := <lloc usb>;

Specs : Linux Lite 3.0 32bit - 1st June, 2016
FILENAME: linux-lite-3.0-32bit.iso
LIVE USER: Login to the live desktop is automatic
BASE: Ubuntu 16.04 LTS

Lots of software : Menu + System + Lite Software

If you want to restore Windows Bootloader and for some reason cannot use the windows installation cd, there is a simple way to do it:

• 1) make sure you have internet working
• 2) Boot with Ubuntu Live CD or Linux Mint Live CD
• 3) Enable the 'universe' repository :
  • System -> Administration -> Software Sources
  • click on the Box next to "Community-maintained Open Source Software (universe)
  • click on Close (twice)
• 4) On the terminal:
  sudo apt-get update sudo apt-get install ms-sys
  then
  *** ubuntu@ubuntu:$ sudo ms-sys --mbr /dev/hda Windows 2000/XP/2003 master boot record successfully written to /dev/hda ***
• 5) Reboot.

Doc, Doc, Doc

Un altre mètode (després de botar Live CD) :
grub-install copies GRUB images into the DIR/boot directory specified by --root-directory, and uses the grub shell to install grub into the boot sector.

grub-install man

Un altre mètode :
You can try SuperGrub live cd to fix your the MBR of your disk : url, WiKi, homepage, get the ISO...

Top

How to get to the GRUB menu at boot-time ?

Hold "Shift" during loading Grub, if you boot using BIOS. When your system boots using UEFI, press "Esc".

Ask Ubuntu "

Top

• list of all installed packages : rpm -qa
  "l /var/log/YaST2/" for a list of YaST2 logs

• verificar requisits d'un paquet : rpm -i --test nom_paket.rpm

• posar un paquet : rpm -ivh nom_paket.rpm

• posar un paquet i els seus requisits (via FTP o HTTP) : rpm -ivh --aid ftp://hostname/pub/redhat/nom_paket.rpm

• treure un paquet : rpm -e nom_paket.rpm

• per saber de quin paquet ve un executable:
  [david@jupiter ~] which cat cat is /bin/cat [david@jupiter ~] rpm -qf /bin/cat coreutils-4.5.3-19

• per saber quines comandes ha instalat un package:
  [sebas@rhv6-64b php]$ rpm -q --filesbypkg php-cli-5.3.3-3.el6.x86_64 php-cli /usr/bin/phar php-cli /usr/bin/phar.phar php-cli /usr/bin/php php-cli /usr/bin/php-cgi

• per saber que conté un package no instalat:
  [sebas@rhv6-64b php]$ rpm -qpl nom.rpm

• software install guide

RPM commands

If you run a 32-bit application, as "install" here, that requires 32-bit libraries, you shall get (if they are missing) :

How to use yum, how to install DVD repo

Network Time Protocol (RFC 1305) & SNTP (RFC 4330)
Server's list NTP : SNTP
I shall use (0..3).europe.pool.ntp.org or (0..3).pool.ntp.org or time.nist.gov

Mitra router comes with 10.27.128.1

Use this url !

Amb una IP especifica :

Nice CMD to Resync :

A Shell to resync shall be:

A list of commands:

• ntpq -p will print out your system's current time status.
• ntpdc -c loopinfo will display how far off the system time is in seconds, based upon the last time the remote server was contacted.
• ntpdc -c kerninfo will display the current remaining correction.
• ntptime is a slightly more different version of "ntpdc -c kerninfo"
• ntpdate -d is another way to see how well NTP is working. This will contact an NTP server and determine the time difference but not change your system's time.
• ntptrace : watch the system synchronize
• ntpdate remote-servername will force a synchronization if you need your system time synchronized immediately. No waiting!

SysAdmin for novices - NTP toolkit

Lets do it:

More Linux commands

Per automatitzar-ho:

Weird error message

Solution : add "localhost" to /etc/hosts !

Dont know how often sync is done:

NTP debug

linux home networking

User can press Ctrl+Alt+Left/Right on keyboard to switch workspaces, or Ctrl+Alt+Up to see all workspaces in overview, with add/remove buttons.

fostips

• use GDB
  • we get a core file
  • determine its type using file core
  • use gdb -c core to fix it

• use strace. See this HOW TO.
  Also ltrace can help (library calls) : wiki, man.

Top

• create a boot disk
  # uname -r 2.2.14-5.0 # mkbootdisk --device /dev/fd0 2.2.14-5.0 ; mkbootdisk-1.2.5-3 (RH 6.2) ; pre-requisit : mkinitrd => mkinitrd-2.4.1-2 (RH 6.2)
• save your configuration files. Here is a list of valuable files you should save.
  /etc/fstab /etc/hosts /etc/hosts.allow /etc/host.conf /etc/hosts.deny /etc/inetd.conf /etc/inittab /etc/lilo.conf /etc/networks /etc/resolv.conf # DNS client. See page 333. /etc/smb.conf # Samba configuration. See page 391.
• engegar en modus "safe mode" o "single user"

  LILO boot : linux single o LILO boot : linux 1

  Això és el que es fa quan els comptes de usuari (inclòs root) expiren.

  User acoount has expired

  També es pot fer

  LILO: {image name} init=/bin/sh rw

  Ara només cal fer /sbin/mount -a (or mount -rw /dev/hda1 /mnt) per muntar la resta de particions i poder fer servir passwd i linuxconf.

  You can also try to erase the password field in the file /etc/shadow. The password is crypted and is between the first and second ":".

  You must end up with a line like this :

  root::11825:0:10000::::

  Then, use passwd to change root password.

  Un altre sequencia es :

  1. boot Toms floppy. Get it now !
  2. after fdisk -l, mount the original root partition on /mnt, as  mount -t ext2 /dev/hda1 /mnt 
  3. edit /mnt/etc/shadow so the root password is removed
  4. umount /mnt
  5. shutdown
  6. reboot and set new root password

• Rescue Packages
  • Ibiblio
  • tomsrtbt Linux on a fpy ( pkunzip + restart in DOS mode + install )
    At P90, use
    boot: bz2bzImage ide1=0x170,0x376,15 or modify the lilo append in buildit.s to make it permanent.

    See "Chapter 7, Customizing" in FAQs. Thankx, Tom (Oehser).

• Rescue floppy list. Each PC should have an associated floppy box containing :
  • Windows rescue floppy
  • BootMagic recovery floppy
  • Linux boot floppy
• verify your system is not "0wn3d"
  • "netstat" - see recent connections
  • "rpm -V" - verify MD5 that have changed

Top

Basic

Medium

Complete - mutt allows "attachments"

URL

Using smtp-client.pl :

It can also authenticate with a Gmail username and password among other things.

To reconfigure it, do :

1. edit sendmail.mc
2. rebuild sendmail.cf : m4 sendmail.mc > /etc/sendmail.cf
3. restart daemon : /sbin/service sendmail stop and /sbin/service sendmail start

The contents of /etc/motd are displayed by login after a successful login but just before it executes the login shell.

Can be a soft link (Debian) :

Debian has a peculiar way of handling /etc/motd. The motd is updated at every reboot, as

Since /etc/motd is a symlink to /var/run/motd in Debian, this works.
How to update your /etc/motd : since /etc/motd basically gets overwritten at every reboot, you need to instead update /etc/motd.tail

On Debian GNU/Linux, dynamic content configured at /etc/pam.d/login is also displayed by pam_exec.

Ubuntu : customize the MOTD via scripts located within the /etc/update-motd.d directory - url

See "man bash".

• interactive login shell :
  1. /etc/profile, if that file exists, then
  2. ~/.bash_profile,
  3. ~/.bash_login, and
  4. ~/.profile

  When a login shell exits, bash reads and executes commands from the file ~/.bash_logout, if it exists.

• when an interactive shell that is not a login shell is started, bash reads and executes commands from ~/.bashrc, if that file exists.

Per verificar que /etc/passwd i /etc/shadow son consistents, fem servir

"watch" is used to run any designated command at regular intervals.

You can run two commands if you quote it properly :

watch at linfo

Cron is a daemon that executes scheduled commands.

Crontab is the program used to install, deinstall or list the tables used to drive the cron daemon.

Verify it is installed and running :

Files and directories at /etc:

• cron.d {directorio}
• cron.daily / cron.allow {?}
• cron.deny
• cron.hourly
• cron.monthly
• cron.weekly
• crontab - te les comandes per executar cron.daily, etc (see bellow)

En detall :

Reload it after a change using

Important differences are that not all distributions support /etc/cron.d, and that the files in /etc/cron.d have to meet a certain number of requirements (beyond being valid cron jobs): they must be owned by root, and must conform to run-parts’ naming conventions (no dots, only letters, digits, underscores, and hyphens).

Sample :

Debug it by

Easy to manage

Some detail :

crontab -l reports on cron entries in /var/spool/cron/crontabs/ - i.e. the per "user crontabs"

/etc/crontab and /etc/cron.d files are "system crontabs" and are not reported by crontab -l

To disable a job in /etc/cron.d, put a dot in its name, as

"crontab -l" and "crontab -e"

The char ";" means

The char "||" - double pipe "||" is logical OR operator in shell expression

The double-ampersand (&&) can also be used in the "command" section to run multiple commands consecutively, but only if the previous command exits successfully. A string of commands joined by the double-ampersand will only get to the last command if all the previous commands are run successfully. If exit error-checking is not required, string commands together, separated with a semi-colon (;).

Sample :

ubuntu

Display previous jobs using "crontab -l"

Each entry must end in a newline character. If not present, no error is displayed but the command will not run.
The best choice is to ensure that your crontab has a blank line at the end.

Compte q esborra el que hi habia a "crontab -l" !

And verify it is active using

Quite a fancy selection

This line executes the disk usage command to get the directory sizes every 2am on the 1st through the 10th of each month.
An e-mail is sent to the email addresses specified with the MAILTO line.
The PATH is also set to something different.

Diferencia entre "&&" i ";" :

Compte : "&&" allows the execution of second command (second operand, to the right of &&) only if the first command executed successfully (exit status 0)

croninfo

De fet el millor es ficar la comanda complexa en un shell i engegar-lo des "crontab -e"

cron runs commands in a limited environment. Only a few environment variables are automatically set. It loads the environment specified by /etc/environment and /etc/security/pam_env.conf, but not about the environment variables you might have set in your .bashrc or .profile

Set the crontab entry

... to take a look at what environment variables are actually set.

Receiving "old style" errors in mail ?

Mind "crontab -e"

Try to use "rm /var/spool/cron/crontabs/root"

Restart

Status

New format :

• user crontabs : 5 fields + command
• system wide /etc/crontab and /etc/cron.d fragments : 5 fields + user + command

Verify format :

Force execution :

Debug :

• check mail - you can specify MAILTO
• capture your ouput : "cmd &> /path/to/output/file"
• check syslog
• check cron is running : "ps -ef | grep cron | grep -v grep"
• provide the full path to your command
• provide a suitable PATH in the crontab file
• insert an empty line at the end
• cron.daily & similar :
  • name without dots
  • execute permission
  • insert she-bang
  • owned by "root"
  • only be writable by "root"

serverfault

One thing that always gets me: You have to leave a blank line at the end of the crontab file. Cron will not run the last line of the crontab! url

• Pi0 crontab
• crontab R3
• crontab R4
• MARS crontab

Overview of the main elements in an LVM system:

url

Useful commands :

• lvm pvdisplay ; physical volume
• lvm vgdisplay ; volume group
• lvm lvdisplay ; logical volume

nohup : keep processes running after you exit from a shell.

myprocess.out & would run the process in background using a subshell. If the current shell is terminated, all subshells are also terminated so the background process would also be terminated.

When running a command using &: and exiting the shell afterwards, the shell will terminate the sub-command with the hangup signal (kill -SIGHUP &pid>). This can be prevented using nohup, as it catches the signal and ignores it so that it never reaches the actual application.

wiki

Another difference is that & alone doesn't redirect the stdout/stderr so if there are any output or error, those are displayed on the terminal. nohup on the other hand redirect the stdout/stderr to nohup.out or $HOME/nohup.out

smartctl : control and monitor utility for SMART Disks

smartd dæmon that does regular monitoring. Configuration file is /etc/smartd.conf. Logs his information with SYSLOG in /var/log/messages
{RH} /etc/rc.d/init.d/smartd start and /etc/rc.d/init.d/smartd stop can be used to start and stop the dæmon

Top

ncurses (new curses) is a programming library providing an application programming interface (API) that allows the programmer to write text-based user interfaces in a terminal-independent manner.

ncurses programming howto

1. open the image with ImageMagick (color depth=16)
2. left button -> Transform -> Crop
3. select a rectangle -> Crop
4. File -> Save -> provide filename

(1) from the imagemagick package, use the convert command:

askubuntu

(2) edit the Imagemagick /etc/ImageMagick-6/policy.xml file to uncomment this line:

... and change it from rights="none" to rights="read|write"

stackoverflow

Top

wiki - formerly an acronym for Common UNIX Printing System

how to disable CUPS :

18.04, 20.04

Install via normal :

Requirements : 4 GB USB

Steps :

1. download ISO
2. from Ubuntu, launch Startup Disk Creator
3. insert new USB
4. select source (iso) and destination (usb) and click "write disk"
5. boot USB in destination computer

Tools by tecmin (Rufus, UNetbootin)

Top

• unmount the unresponsive DVD drive
• get your screen back when it's hosed
• collaboration with screen
• get back the root password
• SSH back door
• remote VNC session through an SSH tunnel
• checking your bandwidth
• command-line scripting and utilities
• spying on the console
• random system information collection

DeveloperWorks

addictive tips, how 2 shout

Start it :

Now its time to configure conky :

To start it with Ubuntu :

To stop the auto-start : "X-GNOME-Autostart-enabled=false"

• gdb
• strace
• nmon
• lsof

Linux Foundation

Install CYGWIN64, users guide

1. run C:\cygwin\setup-x86_64.exe
2. "Install from Internet"
3. root directory "c:\cygwin64\"
4. local package directory : "c:\cygwin"
5. use "System Proxy" settings
6. choose download site -
7. View := Full ;
8. Search := new package name, as "fdisk"

homepage,

I have them at \\w500\C:\Program Files (x86)\GnuWin32\bin>

1. Inkscape ( Vector Graphics Editor )
2. 7-Zip ( Archiver )
3. VLC ( Media Player )
4. VirtualBox ( Virtualization )
5. Miro ( Internet TV )
6. TrueCrypt ( Disk Encryption )
7. Calibre ( eBook Converter and Reader )
8. GnuCash ( Financial Management )
9. GIMP ( Graphics / Simple Photo Editing )
10. Audacity ( Sound Editor / Recorder )

url

Few more :

• Firefox 3.x - nuff said!
• Thunderbird 2.x - Another amazing software from the Mozilla with tons of plug-ins for email client.
• OpenOffice - Great Microsoft Office replacement.
• Pidgin - IM all your friends in one place.
• MPlayer - Now supports most of the Bluray and HD-DVD codecs.
• nmap - The ultimate network exploration and security auditing tool.

Got some Ubutnu restating when playing a video - solution :

1. Tools
2. Preferences
3. Video
4. Output : Automatic -> X11 Video Output (XCB)

3 methods (from here) :

• wine
• dual boot
• VM

VM : this process involves installing a copy of Windows in a “virtual machine” program like VirtualBox, VMware, or Linux’s built-in KVM (Kernel-based Virtual Machine) solution.

VB + wiki, KVM + wiki, VMware + wiki

• mars:\\/home/nicolau/VirtualBox VMs
• /home/nicolau/Downloads/Win10_1909_English_x64.iso
• shared folder : /home/nicolau/sebas/VM_share

FJD 20200110 - url

A Flatpak is a technology for distributing and running applications on Linux, designed to work consistently across different distributions. It packages applications with their dependencies in a "sandbox" environment, promoting both application isolation and cross-distribution compatibility. {Gemini}

Flatpaks are containerized applications.
They require more space because the bring along their own versions of their dependencies instead of relying on system versions.

While a single application will have greater space requirements, the base images [and potentially overlays] will get shared between them and each successive flatpak will potentially require less overhead.

Pros :

• flatpaks are often more current than their distribution packaged versions and they are somewhat isolated from the base system.
• consistency: applications behave the same way regardless of the Linux distribution.

Cons : they're not managed with the rest of your system packages, can have slower start times, occasionally have permissions issues, and take up more space.

Docu

/home/sebas/dades/llibres/informatica/Linux From Scratch systemd.pdf

Albert : buildroot.org tool to generate embedded Linux

• "chroot jail"
• Frozen Bubble game
• Wmaker - NeXTstep-like X window manager.
• how to switch from KDE to Gnome (on the fly ?)
• how to emulate Win/DOS "start ." ?
• guindous migration to Linux :
  • SG24-6380
  • empresa USA ?
• ubuntu - how to move icon using keyboard
  To be used in case screen resolution failure and some icons are not visible, but accessible with "right arrow", that goes from one icon to next

  We can move an open window using "ALT"+F7+"cursors" and ending with "Enter", but not the icon.

Top

• The One Page Linux Manual homepage and pdf.

• A practical guide to Linux
  Mark G. Sobell
  Addison Wesley, 1999 (9th printing)
  ISBN 0-201-89549-8
  

• Red Hat Linux 6 Unleashed
  David Pitts and Bill Ball
  Sams, 1999
  ISBN 0-672-31689-7
  

• Linux complete
  LDC compiled by Grant Taylor
  Sybex, 1999
  ISBN 0-7821-2567-0
  

• Linux Device Drivers
  Alessandro Rubini and Jonathan Corbet
  O'reilly, 2001
  ISBN 0-59600-008-1
  Available on-line both in html and pdf

  Here's also an image

• Using Samba
  Linux Tricks & Tips : numéro spécial Samba

• All docu !
• Nice Install Guide, all RHL-9 manuals : getting started, customization, reference, security, sys admin, glossary ... RHEL5 Administration.
• ifcfg-eth0 keywords & values
• LVM (rh), LVM How-To.
• RHEL v4 SysAdmin guide; all manuals v4. RHEL v4, v5.
• Red Hat Linux 9 - Reference Guide

• SysAdmin for novices - about.com, large and detailed pages

• RH magazine
• linux-mag : how-to articles, tech support, guru guidance, etc - bona revista
• Linux Insider
• Linux Journal, as share a disk between Ubuntu and XP (FAT32-VFAT).
• Linux Gazette - Chung

Top

• Linux FAQ's - una bona llista de preguntes "clàssiques". Home page. Com quan el Linux et diu
  "You dont exist. Go away."

• How to connect Ubuntu to Internet

• RPM finder - quan hem de buscar a quin RPM pertany una comanda. Home page.

• Documentació de aplicacions i buscador.

• Kernel internals (mirror)

• Busca la resposta als grups de Google

• Busca software per Linux a FreshMeat.net i SourceForge

• Some less frequent Linux commands

• Linux programming tips

• Linux requirements

• Linux admin certification prep

• SuSE 8.1 details

• Sota S/390, amb el SuSE 7.0

• En un Netvista A22p / A30p

• Coses de Lilo

• A lite one

• Imprescindible per a portàtils i portàtils i portàtils

• Red Hat customization guide. Document molt extens.

• Llista de eines

• Get Tiny Floppy Linux

• Single IBM site (links to all IBM Linux sites), and a IBM's Howto

• Linux on a Xbox or here

• Linux on a Game Cube

• Cookbook and LDP : The Linux Documentation Project.

  Al LDP hi ha un munt de guies :

  • User's
  • System Admin
  • Programmers Guide

  Good LDP and Programming Doc index ! See "Kernel Internals" doc !

• Linux documentation

• Linux resources on the web

• Linux certification prep.
  LPI certification process : level 1 exam details : exam 101, exam 102, etc
  Also here

• IBM links :
  • tools : X3270, Global Dialer, ILC.
  • And Window Managers.
  • Linux portal
  • Linux client for e-bussiness
  • C4EB RPMs
  • LTC

• Real time Linux

• Nessus homepage

• Forensic PC replication

• Bluez : linux Bluetooth protocol stack.

• Linux in business and for enterprises

• Linux en Extremadura

• Xavi's Application : "VNCVIEWER corrent al damunt el escritori X"

• Linux find apps, as nmap, linpopup, etc

• SuperComputer out of a PS/2 uses Linux

  The supercomputing center scientists said they had chosen the PlayStation 2 because Sony sells a special Linux module that includes a high-speed network connection and a disk drive.

  By contrast, it is almost impossible for researchers to install the Linux system on Microsoft's Xbox game console.

  Using a network of machines is not a new concept in the supercomputing world. Linux, which plays a major role in that world, has been used to assemble high-performance parallel computers built largely out of commodity hardware components. These machines are generally called Beowulf clusters.

• Linux common mistakes

• Mallorquí

• EGB Linux links :
  • LTC
  • White papers
  • ISO images and mirrors. All servers

• Intranet Forums mirror

• Intranet Download FTP3, expire info

• LTP homepage - Linux Test Project !

• Linux en català, català (feb'07) : GNU Linux cat.

• Rosetta : command line for any OS ...

• Guindows-like desktop

• Techno-Fobia : BabelLinux : homepage

• Linux library.

• Linux memory model

• Things I can do on Linux (not on windous)

• BERYL vs Vista desktop

• ELF format - EXE format comparison. Win32 EXE format : exefmt.exe tool.

• Reiser interview & wiki.

• Download any Linux : ArchLinux, Debian, Fedora, Gentoo, Knoppix, Libranet, Lycoris, Mandrake, RedHat, slackware, SuSE, TurboLinux, Yellow Dog.

• Dougie Lawson : Linux for S/390. Good links.

• RH updates (internal)

• directori de foros

• cheat sheet

• xorrades de informàtica

• administrar qualsevol Linux - WebMin - super facil

• The Art of Unix Programming by Eric Steven Raymond (pdf)

• install Sublime Text under Ubuntu (stable, not "dev") : sublimetext

• Ubuntu live with persistent storage, {RRG, 2021/11}

• gaia sky - un google earth de la via lactea

• bginfo alternatives for Linux

• test Linux distros online - VM's in cloud

• Back to main page

• Site map

• Escriu-me !