Bash

#remove all .svn directories
find -type d -name '.svn' -exec rm -rf {} \;

#automatically sanitize file names, renaming the strange characters
detox -r directory


#rename all files and folders to lowercase
find my_root_dir -depth -exec rename 's/(.*)\/([^\/]*)/$1\/\L$2/' {} \;

# run top and log the output for 10 hours:
top –b –n 12000 > myprocesslog

# limit CPU usage
cpulimit -e firefox -l 30
cpulimit -p 1313 -l 30

# combine nice and ionice together.  Avoid disk intensive process to use too much disk cycles:
nice -n 19 ionice -c2 -n7 /path/to/shell.script

#Perl compatible GREP
pcregrep 'Apr\s+(29|30)' /var/log/messages.1

# simply build a mplayer playlist.  -shuffle option to randomize play
find . -name "*.mp3" > files.list
mplayer -shuffle  -playlist files.list


#Opens midnight comander via ssh
mc /#sh:user@192.168.1.23


# LFTP via SSH
lftp sftp://user@example.com

#Usage: mirror [OPTS] [remote [local]]
#When using -R, the first directory is local and the second is remote.
#mirror -R test/


# amazon S3  s3cmd
s3cmd  sync s3://subdomain.domain.com/download/somedir  ./

#sftp to another port different than default 22
sftp -oPort=2222  user@192.168.1.23

#Lazy umount -  to unmount a dead NFS connection.
 sudo umount /media/backup1

umount.nfs: /media/backup1: device is busy
umount.nfs: /media/backup1: device is busy

sudo umount -l /media/backup1

# check what package a command belongs
dpkg -S $(which ls)
coreutils: /bin/ls

# list all files contained in a package
dpkg -L coreutils


# Convert wav to mp3
ffmpeg -i REC014.wav   -ar 44100 REC014.mp2
lame -V2 REC014.mp2   REC014.mp3


# delete all  empty directories  (it works because it will refuse
#to delete directories containing files)
find . -depth -type d -exec rmdir {} \; 2>/dev/null

# delete all empty files or directories in current directory
find . -empty -delete

#The "-empty" option matches either empty files or directories, but since we're
#specifying "-type d" as well, we'll only match empty directories (though you
#could leave off the "-type d" and remove zero length files as well, and possibly
#clean up even more directories as a result). The "-delete" option removes any
#matching directories. What's cool about "-delete" is that it automatically
#enables the "-depth" option so that we don't have to specify it on the command
#line.

# delete empty directories
find . -type d -empty -delete

####################  Images ##############
# Generate an image thumbnail with Image Magic
convert -size 240x180 image.jpg -thumbnail 120x90 thumbs/image.gif

# Mogrify generates thumbnails for an entire directory of images, but be careful
# not to overwrite the images you want to conserve
mogrify -path thumbs -format gif -size 240x180 -thumbnail 120x90 '*.jpg'

## Full Documentation www.imagemagick.org/Usage/thumbnails
convert -size 600x400 maby002.png -thumbnail 300x250 maby002.gif


################## Networking
## restart network card

sudo ifconfig eth1 down
sudo ifconfig eth1 up 192.168.1.2
sudo /etc/init.d/networking restart

sudo route -n
ping 8.8.8.8
sudo vim /etc/resolv.conf