Backup

'''Backup Script'''
located at /usr/local/sbin/backup_vtiger"
scheduled to run at 3:00 AM every day.
creates a zip file of everything in "/var/lib/mysql"
zip file created in "/backup/vtiger_backups"
log file in "/backup/vtiger_backups.log" with output from the script

The backup script checks for both the Apache and MySQL daemons, shutting them down if they are running. Then it creates the zip backup file, after which it restarts the MySQL and Apache daemons. However, it is intelligent enough NOT to restart the daemons if they weren't running in the first place -- that way, if you shut down either or both of the daemons for maintenance, they won't get accidentally restarted by this backup script. Currently, the backup script takes about 15-16 seconds to run, and creates a backup file of about 3.7 MB in size.

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

Imaging for Windows

VI Editor

Goto:

: => line mode, operates on current line unless specific line numbers are specified

^ or 0 ==> beginning of line
$ ==> end of line

:0==>beginning of file
G ==> end of file

nG ==> go to line n
:n ==> go to line n

Return ==> first non-blank char

H ==> top line on screen
L ==> last line on screen
M ==> middle of screen
Ctrl+L ==> Redraw screen??
b              beginning of previous word
w              beginning of next word
e              end of current/next word
0 (zero) or ^ beginning of line
$              end of line
(              beginning of current/previous sentence
)              beginning of next sentence
{              beginning of current/previous paragraph
}              end of current paragraph
H              top line on screen
M              middle line on screen
L              bottom line on screen

Search and Replace

The search command is /.  
/hello => search for "hello"
n repeats the search in the same direction
N repeats the search in the opposite direction

:s/search_string/replacement_string => global search and replace

:s/search_string/replacement_string/g => global search and replace


:s/search_string/replacement_string/gc => global search and replace with confirm

Yank (copy) and Put (paste)

yw yank rest of word
y$ yank rest of line
yy yank entire line
Y yank entire line

p put yanked/deleted text before cursor
P put yanked/deleted text after cursor

ln

A symbolic link, also known as a soft link or symlink, is a special type of file that points to another file or directory.

ln -s {target} {symlink name}

For, to example create a symlink for /home/domain/mydomain:

ln -s /home/domain/mydomain mydomain