This is a list of things I either think are neat, or things I'm always Googling.

Locale Settings:

export LANGUAGE=en_US.UTF-8
export LANG=en_US.UTF-8
export LC_ALL=en_US.UTF-8

Process Tree:

pstree -p

Create a .gitkeep file in all empty directories:

find . -type d -empty -print0 | xargs -0 -I{} touch {}/.gitkeep

Remove all files in /tmp older than 2 days

find /tmp -maxdepth 1 -type f -mtime +2 -exec rm -i "{}" \;

Shell Startup Files:

• Linux/Bash/TTY:
  /etc/profile → first of ~/.bash_profile, ~/.bash_login, ~/.profile that exists

• Linux/Bash/XTerm:
  /etc/bash.bashrc → .bashrc

• Linux/Bash/Scripts (#!/usr/bin/env bash):
  looks for $BASH_ENV var and sources the expansion of that variable

• Linux/ZShell/TTY:
  /etc/zshenv → ~/.zshenv → /etc/zprofile → ~/.zprofile → /etc/zshrc → ~/.zshrc → /etc/zlogin → ~/.zslogin (/etc/z* is the default; however /etc/zsh/z* seems to be common (at least on Ubuntu))

• Linux/ZShell/XTerm:
  /etc/zshrc → ~/.zshrc

• Linux/ZShell/Scripts (#!/usr/bin/env zsh):
  /etc/zshenv

• OSX/Bash/TTY/XTerm:
  /etc/profile → first of ~/.bash_profile, ~/.bash_login, ~/.profile that exists

• OSX/Bash/Scripts (/usr/bin/env bash):
  looks for $BASH_ENV var and sources the expansion of that variable

• OSX/ZShell/TTY/XTerm:
  /etc/zshenv → ~/.zshenv → /etc/zprofile → ~/.zprofile → /etc/zshrc → ~/.zshrc → /etc/zlogin → ~/.zslogin

• OSX/ZShell/Scripts (/usr/bin/env zsh):
  /etc/zshenv

Setting your hostname—Debian and Ubuntu:

1. Edit /etc/hostname and add you unqualified hostname, e.g., echo "parabola" > /etc/hostname

2. Run hostname -F /etc/hostname to update your hostname

3. Edit /etc/hosts:

   127.0.1.1 parabola.tylercipriani.com parabola localhost

Cronjob Time Syntax:

• m h dom m dow <what_to_do>
  • m - minute(0–59)
  • h - hour(0–23)
  • dom - day-of-month(0–31)
  • m - month(0-11)
  • dow - day-of-week(0–6)
  • <what_to_do> - anycommand

Send mail

echo "Message Body" | mail -s "Mail Subject" [email protected]

Send mail to multiple people:

echo "Message Body" | mail -s "Mail Subject" -c "[email protected] [email protected]" [email protected]

Git show contents of stash

git stash show -p stash@{1}

IPTables

• Block an IPAddress

  iptables -A INPUT -s "$BLOCK_THIS_IP" -j DROP
  

• Insert a rule to allow inbound tcp traffic on port 8000 (puts the rule at the top)

  iptables -I INPUT -i eth0 -p tcp --dport 8000 -j ACCEPT
  

Tar (Tape Archive Utility)

• Create gzipped tar from file or directory

  tar -cvzf tarfile.tar.gz directory file otherfile
  

• Create bzipped tar file from file or directory

  tar -cvjf tarfile.tar.bz2 directory file otherfile
  

• List contents of tar.gz file

  tar -tvzf tarfile.tar.gz
  

Wget/cURL

• Rip a whole site with wget:

  wget --recursive --no-clobber --page-requisites --html-extension --convert-links --restrict-file-names=windows --domains <domain-name> --no-parent http://<domain>
  

• Upload file via cURL

  curl -X 'POST' -H 'Accept: application/json' -F 'file_name=Test File' -F 'file_contents=@/path/to/file.type' www.example.com/file/add
  

• Fill login form via cURL

  curl -X 'POST' -F 'username=tyler' -F 'password=pass123' www.example.com/login
  

MySQL

• Single DB Dump

  mysqldump --compress -h localhost --quick --single-transaction [db_name] > [dumpfile]
  

• Nice DB Dump

  mysqldump -h localhost -u [username] -p --add-drop-database --skip-comments --routines --compress --quick --single-transaction --databases [db_name] > [dumpfile]
  

• Dump tables that match pattern:

  mysqldump -h localhost --quick --single-transaction [db_name] `mysql -ND [db_name] -h localhost -e "show tables like '[pattern]'" | awk '{ printf $1" " }'` > dumpfile.sql
  

Debug bash scripts, add:

set -x

Forward new port in existing SSH session:

<newline>
~C
ssh> ?

List currently established, closed, orphaned and waiting TCP sockets:

ss -s

netstat -tlnp vs ss -ln

$ time netstat -tlnp                                                                                                   127 ↵
netstat -tlnp  0.00s user 0.02s system 97% cpu 0.016 total

$ time ss -ln       
ss -ln  0.00s user 0.00s system 83% cpu 0.005 total

Check disk I/O:

vmstat 1 10

What's using disk I/O:

dstat --top-io --top-bio

Show io per-device (needs sysstat package on debian):

iostat -sk 2

Linux Fun Crap

• Generate a list of your most used commands—

  history | sed "s/^[0-9 ]*//" | sed "s/ *| */\n/g" | awk '{print $1}' | sort | uniq -c | sort -rn | head -n 100 > commands.txt

• The Useless Use of cat Award (partmaps)

• Terminal Keynote (Ruby) (github)

• Boom. Motherfucking Text Snippets on the command line (zachhholman)

• Spark sparklines for your shell (zachholman)

• Lolcat (github)

• cowsay (github)

• Ponysay (github)

• FIGlet (figlet)

• Libcaca (caca.zoy)

• Toilet (caca.zoy)

• Boxes (thomasjensen)

• Cadubi (perl) (langworth)

• img2txt (hit9)

• Nyancat (klange.github)

• CMatrix (asty)

• janbrennen rice (github)

• dotshare.it (dotshare.it)

• linux logo (freecode)

• bb (aa-project)

• Powerline Font symbols (powerline)

• Stupid Programmer Tricks/Starwars gifs (rarlindseysmash)