Handy Linux Commands

gistfile1.md

Get just the IP of a hostname

• dig +short A <hostname>

Find the 10 largest files on the disk

• du -a / | sort -n -r | head -n 10

Find/Replace text in files

• sed -i 's/old-word/new-word/g' *.txt

Copy a file/directory into multiple dirs at the same time

• echo *.*/public_html/ | xargs -n 1 cp -R dir_to_copy/

Helpful CD commands

• cd (with no directory) takes you to your home dir (ie: cd ~)
• cd - (with a hyphen) takes you back to the last directory you cd'd to

Re-run the previous command as sudo

• sudo !!

Rename the file extensions of all the files in a directory

• rename 's/.html$/.php/' *.html

Tunnel Traffic Over SSH

• ssh -ND 9999 user@server.com

Once you enter your password, nothing will happen. This is because the -N switch tells SSH to (N)ot open an interactive session TIPS: Use the -C switch to enable compression

Quickly share files via python's simplehttpserver

• cd /dir/with/files/ && python -m SimpleHTTPServer 8000

Starting a command with a space will exclude the command from history

• <space>command

Use Brace Expansion to quickly rename/copy files

• cp /var/www/foo.php{,.bak}

Is the same as: cp /var/www/foo.php /var/www/foo.php.bak

Get the 10 most popular commands

• history | awk '{print $2}' | awk 'BEGIN {FS="|"}{print $1}' | sort | uniq -c | sort -nr | head

Convert MKV to MP4

Note: requires libav-tools (sudo apt-get install libav-tools)

• avconv -i filename_in.mkv -codec copy filename_out.mp4