Comandos Útiles

Convert a flv video file to avi using mencoder

mencoder your_video.flv -oac mp3lame -ovc xvid -lameopts preset=standard:fast
    -xvidencopts pass=1 -o your_video.avi

Mail with attachment

tar cvzf - data1 data2 | uuencode data.tar.gz | mail -s 'data' you@host.fr

Show the UUID of a filesystem or partition

sudo vol_id -u /dev/sda1

Send pop-up notifications on Gnome

notify-send ["

Change Gnome wallpaper

gconftool-2 -t string -s /desktop/gnome/background/picture_filename

Send a .loc file to a garmin gps over usb

gpsbabel -D 0 -i geo -f "/path/to/.loc" -o garmin -F usb:

Grep colorized

grep -i --color=auto

Convert a SVG file to grayscale

It requires inkscape 0.46 and lxml packages

inkscape -f file.svg --verb=org.inkscape.color.grayscale --verb=FileSave
    --verb=FileClose

Watch Network Activity in Real-time

lsof -i

Burn CD/DVD from an iso, eject disc when finished.

cdrecord dev=0,0,0 -v -eject yourimage.iso

Backup your CD/DVD making a iso file

dd if=/dev/cdrom of=image.iso

Launch a VirtualBox virtual machine

VBoxManage startvm "name"

Delete an hard disk entry in Virtualbox registry

sed -i '/Centos/d' VirtualBox.xml

Find and delete oldest file of specific types in directory tree

find / \( -name "*.log" -o -name "*.mylogs" \) -exec ls -lrt {} \; | sort -k6,8 | head -n1 | cut -d" " -f8- | tr -d '\n' | xargs -0 rm

Remove all backup files in my home directory

find ~user/ -name "*~" -exec rm {} \;

Recursivly search current directory for files larger than 100MB

find -size +100M

Print basename of files

find . -name '*.deb' -printf "%f\n"

View the system memory in clear text

 hexdump -e '90/1 "%_p" "\n"' /dev/mem | less

Convert a file from ISO-8859-1 (or whatever) to UTF-8 (or whatever)

tcs -f 8859-1 -t utf /some/file

Find UTF-8 text files misinterpreted as ISO 8859-1 due to Byte Order Mark (BOM) of the Unicode Standard.

find . -type f | grep -rl $'\xEF\xBB\xBF'

Montar una Carpeta remota de Windows usando Samba

mount -t smbfs -o username=usuario,group=dominio //servidor/carpeta /media/APPL/

List all PostgreSQL databases. Useful when doing backups

psql -U postgres -lAt | awk -F\| '$1 !~ /^template/ && $1 !~ /^postgres/ && NF > 1 {print $1}'

Postgresql SQL to show count of ALL tables (relations) including relation-size

SELECT relname, reltuples, pg_relation_size(relname) FROM pg_class r JOIN pg_namespace n ON (relnamespace = n.oid) WHERE relkind = 'r' AND n.nspname = 'public' ORDER BY relname;

Convert all files in a dir of a certain type to flv

for f in *.m4a; do ffmpeg -i "$f" "${f%.m4a}.flv"; done

For all flv files in a dir, grab the first frame and make a jpg.

for f in *.flv; do ffmpeg -y -i "$f" -f image2 -ss 10 -vframes 1 -an "${f%.flv}.jpg"; done

Backup with SSH in a archive

PRIVATEKEY - Of course the full path to the private key

HOST - The host where to get the backup

SOURCE - The directory you wish to backup

DESTINATION - The destination for the backup on your local machine

 ssh -i $PRIVATEKEY $HOST -C 'cd $SOURCE; tar -cz --numeric-owner .' | tee $DESTINATION/backup.tgz | tar -tz

Otra forma:

ssh user@host 'cd dir; tar zcf - .' > file.tgz

Email HTML content

mailx bar@foo.com -s "HTML Hello" -a "Content-Type: text/html" < body.htm

Send a binary file as an attachment to an email

uuencode archive.tar.gz archive.tar.gz | mail -s "Emailing: archive.tar.gz" user@example.com

Delete Empty Directories

find . -type d -exec rmdir {} \;

Add -depth to prevent find complaining (it will ensure empty trees are deleted, too) and --ignore-fail-on-non-empty to stop rmdir (gnu version) complaining:

find . -depth -type d -exec rmdir --ignore-fail-on-non-empty {} \;

Of course for efficiency, you can use xargs:

find . -depth -type d -print0 | xargs -0 rmdir --ignore-fail-on-non-empty

Search and replace in multiple files and save them with the same names - quickly and effectively!

for files in $(ls -A directory_name); do sed -i 's/search/replaced/g' $files; done;

O también :

find . -name "*.php" -exec sed -i 's/old/new/g' {} \;

Using scanner device from command line

scanimage -d mustek_usb --resolution 100 --mode Color > image.pnm

Extract track 9 from a CD

mplayer -fs cdda://9 -ao pcm:file=track9.wav

Record a screencast and convert it to an mpeg

ffmpeg -f x11grab -r 25 -s 800x600 -i :0.0 /tmp/outputFile.mpg

Find broken symlinks and delete them

Using the -L flag follows symlinks, so the -type l test only returns true if the link can't be followed, or is a symlink to another broken symlink.

find -L /path/to/check -type l -delete

If you don't want to delete them, but just want to list them, do

find -L /path -type l

If you want to delete them with confirmation first, do

find -L /path -type l -exec rm -i {} +

Alias para obtener la clave OpenPGP keys para PPAs de Launchpad en Ubuntu

alias launchpadkey="sudo apt-key adv --keyserver keyserver.ubuntu.com --recv -keys "

Uso : launchpadkey 4E5E17B5

Para montar una imagen iso

mount image-file.iso /mnt/cdrom -o loop

Crear una imagen iso de un CD o un DVD

 mkisofs -r -o imagen.iso /cdrom/

Reemplazar los espacios en blanco por guiones de subrayado en el nombre de varios archivos

rename 'y/ /_/' *

Cambiar permisos solo a archivos

find . -type f -print0 | xargs -0 chmod -x

Simple list of apache2 virtualhosts

/usr/sbin/apache2ctl -S

Restart apache only if config works

alias restart='apache2ctl configtest && apache2ctl restart'

Save man pages to pdf

man -t man | ps2pdf - > man.pdf

Print man pages to PDF

man -t [command] | lp -d PDF -t [command].pdf

Update twitter from shell

curl -u user:pass -d status="Tweeting from the shell" http://twitter.com/statuses/update.xml

Convert an avi video to mp4

ffmpeg -i tuvideo.avi -s 480x320 -aspect 16:9 -b 768k -ab 64k -ar 22050 -r 30000/1001 tuNuevoVideo.mp4

Chequear si el sistema es de 32bits o 64bits

getconf LONG_BIT

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