How do you run a script on login in *nix?

I know I once know how to do this but... how do you run a script (bash is OK) on login in unix?

From stackoverflow Nate

• The script ~/.bash_profile is run on login.

  From William Keller

• Place it in your bash profile:

  ~/.bash_profile

  From gbjbaanb

• If you are on OSX, then it's ~/.profile

  William Keller : On OS X with bash, ~/.bash_profile works fine.

  Craig B. : Yes, but ~/.profile already exists.
  From Craig B.

• From wikipedia http://en.wikipedia.org/wiki/Bash

  When Bash starts, it executes the commands in a variety of different scripts.

  When Bash is invoked as an interactive login shell, it first reads and executes commands from the file /etc/profile, if that file exists. After reading that file, it looks for ~/.bash_profile, ~/.bash_login, and ~/.profile, in that order, and reads and executes commands from the first one that exists and is readable.

  When a login shell exits, Bash reads and executes commands from the file ~/.bash_logout, if it exists.

  When an interactive shell that is not a login shell is started, Bash reads and executes commands from ~/.bashrc, if that file exists. This may be inhibited by using the --norc option. The --rcfile file option will force Bash to read and execute commands from file instead of ~/.bashrc.

  From Svet

• When using Bash, the first of ~/.bash_profile, ~/.bash_login and ~/.profile will be run for an interactive login shell. I believe ~/.profile is generally run by Unix shells besides Bash. Bash will run ~/.bashrc for a non-login interactive shell.

  I typically put everything I want to always set in .bashrc and then run it from .bash_profile, where I also set up a few things that should run only when I'm logging in, such as setting up ssh-agent or running screen.

  From Michael Johnson

• If you wish to run one script and only one script, you can make it that users default shell.

  echo "/usr/bin/uptime" >> /etc/shells
  vim /etc/passwd  
    * username:x:uid:grp:message:homedir:/usr/bin/uptime
  

  can have interesting effects :) ( its not secure tho, so don't trust it too much. nothing like setting your default shell to be a script that wipes your drive. ... although, .. I can imagine a scenario where that could be amazingly useful )

  From Kent Fredric

• Add an entry in /etc/profile that executes the script. This will be run during every log-on. If you are only doing this for your own account, use one of your login scripts (e.g. .bash_profile) to run it.

  From ConcernedOfTunbridgeWells

• At login, most shells execute a login script, which you can use to execute your custom script. The login script the shell executes depends, of course, upon the shell:

  • bash: .bash_profile, .bash_login, .profile (for backwards compabitibility)
  • sh: .profile
  • tcsh and csh: .login
  • zsh: .zshrc

  You can probably find out what shell you're using by doing

  echo $SHELL
  

  from the prompt.

  dr-jan : echo $0 should reveal which shell is being used, although occasionally I've seen 'sh' reported, when it's really 'ksh' - on HP-UX or Solaris I think.
  From pjz

• Search your local system's bash man page for ^INVOCATION for information on which file is going to be read at startup.

  man bash
  /^INVOCATION
  

  Also in the FILES section,

     ~/.bash_profile
            The personal initialization file, executed for login shells
     ~/.bashrc
            The individual per-interactive-shell startup file
  

  Add your script to the proper file. Make sure the script is in the $PATH, or use the absolute path to the script file.

  From jtimberman

• Launchd is a the prefered way in os X.

  If you want it to run on your login put it in ~/Library/LaunchAgents

  Start launchd item

  launchctl load /Library/LaunchDaemons/com.bob.plist

  Stop item

  launchctl unload /Library/LaunchDaemons/com.bob.plist

  Example com.bob.plist

  <?xml version="1.0" encoding="UTF-8"?>
  <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
  <plist version="1.0">
  <dict>
  <key>Label</key>
  <string>com.bob</string>
  <key>RunAtLoad</key>
  <true/>
  <key>ProgramArguments</key>
  <array>
  <string>/usr/bin/java</string>
  <string>-jar</string>
  <string>/Users/user/program.jar</string>
  </array>
  </dict>
  </plist>
  

  From Milhous