This document provides a collection of tips and shortcuts for using Linux, including commands for system maintenance, file management, backups, updates, networking, and more. Some key tips include using sudo rm -rf ~/.local/share/Trash/files/* to empty a stuck trash, fsck to check the file system, and fdisk -l to view disk partitions. It also lists many keyboard shortcuts for navigating desktop environments and applications.

1. Algunos trucos sencillos.
Para ir terminando este curso, les dejo algunos trucos, que me son muy útiles, y algunas hojas,
llamadas cheats, que son los viejos trencitos del liceo... o sea, cartas u hojas con recordatorio de los
comandos más usados en linux.
Muchas veces algo se queda atorado en la papelera y no se quiere ir, entonces corremos:
sudo rm -rf ~/.local/share/Trash/files/*
y listo.
Fsck – comprobar si el sistema está ok, o en su defecto arreglar problemas de archivos corruptos.
Para ejecutar el comando debemos arrancar el sistema en el modo “recovery mode” -> desmontar
las particiones : tanto / como /home ( o solo la partición raiz / si /home no es una partición, sino
un directorio dependiente de / ) -> ejecutar fsck
1- Para saber que particiones hay en el sistema, se ejecuta el comando fdisk -l ( desde recovery
mode no hace falta poner sudo porque ya estas con permisos de root; desde la sesión normal si que
habría que poner: sudo fdisk -l ) te dice el sdaX y el sdaY: Lista las tablas de particiones: las
particiones son usualmente de uno de los siguientes tipos: /dev/hda /dev/hdb ( /dev/hd[a-h]
para discos IDE, ) , o /dev/sda /dev/sdb ( /dev/sd[a-p] para discos SCSI, ) , /dev/ed[a-d]
para discos ESDI, /dev/xd[ab] para discos XT).
2- Una vez hemos sabido cual es la partición-es donde esta el sistema, ( para verificar un sistema de
archivos es muy aconsejable hacerlo mientras éste está desmontado), si por ejemplo la partición raiz
/ esta en /dev/sda1 y la partición /home en /dev/sda2 las desmonto con sudo umount /dev/sda1
sudo umount /dev/sda2
3- Ejecuto el comando sudo fsck -c -y /dev/sda1 /dev/sda2 Se tardan un poco, pero te dejan los
discos y el sistema super finos
Sacado de http://hatteras.wordpress.com/2009/04/21/fsck-file-system-consistency-check/
(mucho ojo con fsck, pueden quedarse sin nada en el home si no desmontan primero, están
avisados...)
Hacer un backup de un dvd, o sea copiarlo a disco duro...
dvdbackup -M -i /dev/dvd -o /donde/quieras/ponerlo
Keyboard shortcuts (Atajos de teclado)
Ctrl+A = Select all (In Documents, Firefox, Nautilus, etc, not Terminal)
Ctrl+C = Copy (In Documents, Firefox, Nautilus, etc, not Terminal)
Ctrl+V = Paste (In Documents, Firefox, Nautilus, etc, not Terminal)
F9 = Toggle Sidebar
F2 = Rename
Ctrl+Shift+N = Create new folder
Ctrl+N = New (Create a new document, not in terminal)

2. Ctrl+O = Open (Open a document, not in terminal)
Ctrl+S = Save (Save the current document, not in terminal)
Ctrl+P = Print (Print the current document, not in terminal)
Ctrl+E = Send To... (Send the current document to an email recipient or remote location, not in
terminal)
Ctrl+W = Close (Close the current document, not in terminal)
Ctrl+Q = Quit (Quit the application, not in terminal)
Ctrl+H = Show hidden files
Ctrl+F = File browser
Ctrl+T = Move to trash (dangerous)
Ctrl+L = Open location (folders, files, URLs, etc)
Ctrl+Alt+F1 = Switch to the first virtual terminal
Ctrl+Alt+F2(F3)(F4)(F5)(F6) = Select the different virtual terminals
Ctrl+Alt+F7 = Switch to current terminal session with X
Ctrl+Alt+L = Lock screen
Crtl+Alt+Delete = Log out
Ctrl+Alt+D = Hide all windows and focus desktop
Alt+F1 = Launch applications menu
Alt+F2 = Launch "run application" dialogue
Alt+F7 = moves the current window (can be moved with mouse OR KEYBOARD)
Alt+F8 = resizes current window (again, with mouse OR KEYBOARD)
Alt+F9 = minimizes current window
Alt+F10 = maximizes current window
Alt+Space = brings up that funny window menu with with 'Always on Top' and 'Minimize' and
'Maximize' and all that jazz
Alt+F5 = returns window to 'normal' or previous size
Alt+F4 = closes window (usually)
Alt+Home = jump to home folder
Alt+Enter = file / folder properties
Ctrl+Alt+Backspace = Kill X server
Alt+Tab = Switch between open programs
Printscrn = Print screen
<+Space = scrolls current tab/window down
<+Backspace = scrolls current tab/window up
Ctrl+Alt+Right/Left Arrow = Move to the next virtual desktop
Ctrl+Alt+Shift+Right/Left Arrow = Take current window to the next virtual desktop
Command line / Terminal shortcuts
Ctrl+C = Kill process (Kill the current process in terminal, also used to copy elsewhere)
Ctrl+Z = Send process to background
Ctrl+D = Log out from the current terminal. In X, this may log you out after a shuting down the
emulator.
Ctrl+A = Home (Move cursor to beginning of line)

3. Ctrl+E = End (Move cursor to end of line)
Tab = List available commands from typed letters (Ex: type iw and click tab, output = iwconfig
iwevent iwgetid iwlist iwpriv iwspy)
Ctrl+U = Delete current line
Ctrl+K = Delete current line from cursor
Ctrl+W = Delete word before cursor in terminal (Terminal only, also used to close the current
document elsewhere)
Arrows up and down = Browse command history
Ctrl+R = History search (Finds the last command matching the letters you type)
Shift+PageUp / PageDown = Scroll terminal output
Ctrl+L = Clears terminal output
Shift+insert = Paste
Ctrl+Shift+C = Copy
Ctrl+Shift+V = Paste
Mouse
Mousewheel click or 3rd mouse button = Paste selected text (Select any text in any window and
paste where you want. Terminal / Firefox / Gnome apps)
Crear un shortcut propio
To make a shortcut in Gnome, run gnome-keybinding-properties or goto System->Preferences-
>Keyboard Shortcuts
Ubuntu linux cheatsheet - Apache
htdocs folder
/var/www
apache configuration files
/etc/apache2/
vhosts definitions
/etc/apache2/sites-available
Create a link to each definition in /etc/apache2/sites-enabled: ln -s /etc/apache2/sites-enabled/
mysite.lnk /etc/apache2/sites-available/mysite
Or with newer versions of Ubuntu: a2ensite mysite for enabling and a2dissite mysite for
disabling
start/stop/restart apache
sudo /etc/init.d/apache2 start/restart/stop
Logs
/var/log/apache2
PHP
php ini
/etc/php5/apache2/php.ini
Sessions temp dir
/var/lib/php5

4. Pear and all of that stuff
/usr/share/php5
mysql
config file (my.cnf)
/etc/mysql/my.cnf
Delete tables with a certain pattern (drop tables like)
mysql –user=theuser –password=thepassword -N -e "show tables like 'whatever%'" db_name |
perl -e 'while(<>){chomp; push @tables, $_;}print "drop table " . join ("," ,@tables) . "n";' | mysql
–user=theuser –password=thepassword db_name
Archivos
Find files which have been modified today
find . -mtime -1 -print
Find all backup files in a directory
find . -name *~ -print
Find all backup files and delete them!
find . -name "*~" -exec rm {} ;
Change permissions for all folders only
find . -type d -exec chmod g+x {} ;
Set the group id bit (so files created later in the folder belong ot the folder's group)
chmod g+s directory
Uncompress lots of zips with just one line of terminal commands
find *.zip -exec unzip {} ;
Find only files
find . -type f
Find only files … and delete them!
find . -type f -delete
Recursively find files which contain a given text
grep -lir "a given text" *
Available space in disk
df -h (in fact this return available space in each mount in the system)
Show differences between two files without taking into account whitespace (very useful when line
returns and spaces/tabs are messing up normal diffs)
diff -w file1 file2
Backups
archive and compress a whole directory
tar cvfz archive.tar.gz dname
backup a database
mysqldump db_name –user=username –password=password > database_dump.sql
backup all databases
mysqldump -u username -p –all-databases >/tmp/databases.dump
All-in-one: get a remote database dump, compress it, download and uncompress in your local
machine
ssh your_host "cd dumps_dir; mysqldump –user your_user –password=your_pass –host=db_host
database_name | gzip > database_name.gz"
scp your_login@your_host:dumps_dir/database_name.gz ./sql/
gunzip ./sql/database_name.gz

5. Compress a file with zip
zip outputfile.zip file1 file2 file3… fileN
Download a remote directory to current directory
scp -rv yourlogin@yourhost:~/web/public_html .
Updates
Remove unused packages
sudo apt-get autoremove
Manually update greyed out entries in the update manager
Go to Synaptic Package Manager, order by the status column (i.e. the first one), select all the
packages with a star (*) over a green background, and select "Mark for upload".
Distribution update
sudo apt-get dist-upgrade
sudo gksu "update-manager -c"
Crisis!! X server doesn't work after updating the distribution - boot in safe mode and run
sudo apt-get install –reinstall xserver-xorg
sudo dpkg -reconfigure xserver-xorg
System
Turn off
sudo shutdown
Reboot
sudo reboot
List mounted devices and disks and other info
sudo fdisk -l
Static file system information
/etc/fstab
Fcsk - boot from live CD (it won't allow you to fsck a mounted drive)
open a console with ctrl+alt+f1
then sudo fsck /dev/sdb, etc
Another option: sudo e2fsck -p -f -v /dev/sda
Force fsck on boot
sudo touch /forcefsck and reboot!
Xorg
Restart xorg
press ctrl+alt+backspace
Redes
Download a file with curl
curl -o outputfile source_url
Subversion
List info for a remote repository
svn info svn://repository_url (or http://repository_url, etc)
svn info also works with local resources: svn info . lists info for current directory
List files in a repository path

6. svn list svn://repository/path
VirtualBox
Recompiling kernel module after upgrading the kernel:
sudo aptitude install linux-headers-$(uname -r)
sudo /etc/init.d/vboxdrv setup
Some people suggest using "sudo aptitude install virtualbox-ose-modules-generic" which is "a
metapackage". I haven't tested it.
PulseAudio
Stop and restart
pkill pulseaudio; pulseaudio &
PGP & co
Clearsign a file with a non-default key
gpg –default-key [KEYID] –clearsign [FILENAME]
Y con esto y las Cheats tienen para entretenerse, y empezar a aprender...
Muchas gracias a todos.
Daniel Mato – 27.7.10