All commands

Select a file/folder at random.

grep '^[^#]' sample.conf

\__/ |||| \_________/

| |||| |

| |||| \- Filename

| ||||

| |||\- Only character in group is '#'

| |||

| ||\- Negate character group (will match any cahracter *not* in the

| || group)

| ||

| |\- Start new character group (will match any character in the

| | group)

| |

| \- Match beginning of line

|

\- Run grep

Empty lines will also be not matched, because there has to be at least one non-hash-sign character in the line.

Remove your BASH history and then link it to /dev/null

Shows the status of SElinux.

-- fir3net.com --

Simplicity tends to win out on commandlinefu.com Also, why type multiple filenames when range operators work too. Saves finger abuse and time and reduces the chances for mistakes.

Tail is much faster than sed, awk because it doesn't check for regular expressions.

convert your text to ascii art

WARNING! This command may set an invalid permission under your current directory.

This command will set the 0755 permissions to all directories under your current directory. An alternative version of this command is: find ~/.ssh -type d -exec chmod 0700 {} \;

Ever need to output an entire directory and subdirectory contents to a file? This is a simple one liner but it does the trick every time. Omit -la and use only -R for just the names

this command shows the space used in postgres directory.

If you edit your .profile you need to refresh it for changes to take place. Simple way to refresh is logout and login. This command is the quickest way to do it.

If you're deleting some variables, they would not get nulled with this command but just removed.

This will create a new directory called MyProject with a pom.xml and the following tree structure:

MyProject

|-->pom.xml

|-->src

| |-->main

| | |-->java

| | | |-->my

| | | | |-->work

| | | | | |-->App.java

| |-->test

| | |-->java

| | | |-->my

| | | | |-->work

| | | | | |-->AppTest.java

Will rot 13 whatever parameter follows 'rot13', whether it is a string or a file. Additionally, it will rot 5 each digit in a number

Use optimized sed to big file/stream to reduce execution time

Use

insted of sed

if you want to replace "foo" with "bar" in all files in a folder, and put the resulting files into a new subfolder

Finds a string in files recursively below the current directory on systems without the "egrep" and its "-r" functionality.