Commands

Tab should list more files How to list only directories

Disk Utilization: du

-h human readable
-s summary

Examples:
du -sh    =>   total size of current directory human readable

File Count using find

This counts all of the files in the current directory and all children directories:

find . -type f | wc -l

Find

The basic syntax of the find command is:

$ find . -name foo.bar

This will recurssively search starting in the current directory (.), and all subdirectories of the current directory, for the file named <filename>.


To filter out "Permission Denied" messages, use:

$ find . -name foo.bar -print 2>/dev/null

 

What version of Linux am I running?

uname -a 

chmod

permissions are represented by 3 digits

ugo => u=owner, g=group, o=otherw

1=execute, 2=write, 4=read

chmod 664 file => read and write access for the owner and group, read only for all others. 

 chmod 0 => removes all priveledges for all

chmod -R 755 => recursive, read+write+execute for owner, read+execute for group and others

chown

chown -R apache:apache drupal

grep

Generalized Regular Expression Parser

grep string file => finds all occurances of <string> in <file>

-i => ignore case

-w => whole word

-l => list file name only

grep -r 'searchstring' /home => recursive - search all files

find /somedir -name '*.doc' -print | xargs grep 'somestring' /dev/null =>

recursive - specify specific file pattern

 

tar

To create a compressed tar file: tar -cvf

To uncompress a tar file: tar -xvf

c=compress x=extract z=zip-format v=verbose (optional) f=file (must be last)

Examples: Create:

tar -czvf mystuff.tgz mystuff/

tar -cvzf file.tar.gz inputfile1 inputfile2

Extract: tar -xzvf mystuff.tgz tar -xvzf file.tar.gz

whereis

Handy way to find a file or directory: Example: whereis mysql