Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

When you log in to a shell on a Unix system there are usually some files that are run in your home directory. You'd use these to, for example, set up aliases and additions to your $PATH.

But, how do I know exactly which file that is? How do I figure out exactly which file I need to edit (or add)?

I'm after a generic way I can use on any Unix system. Say all you have to begin with is an IP address/hostname and a username and password for an SSH login. You connect and login. Now what do you do?

share|improve this question
2  
Depends on your shell. For bash, see man bash section Invocation. –  ott-- Feb 6 '13 at 10:27

1 Answer 1

up vote 8 down vote accepted

The profile is usually run on each login. The system-wide login file is /etc/profile and the user-specific files are usually ~/.profile. Some shells have their own profile and rc files, for example bash has .bashrc which is run by non-login bash shells and .bash_profile which is run by login bash shells. The system-wide bashrc is /etc/bash.bashrc

Thus, you would use .profile for things that should be run by login shells and .bashrc (or an equivalent) for things that should be run by non-login shells (aliases, setting up the env and similar)


bash clarification:

There are two kinds of shells: login and non-login shells. A login shell is the shell run when a user logs in. Non-login shells are all other shells. For example, when you log in via ssh or on a console, the shell you get is a login shell.

bash login shells run at startup:

  • /etc/profile
  • The first existent file of the following: ~/.bash_profile, ~/.bash_login, ~/.profile

bash non-login interactive shells run at startup:

  • /etc/bash.bashrc
  • ~/.bashrc

In some (most?) unices that come with bash, the profile sources ~/.bashrc, so ~/.bashrc is run for both login and non-login interactive shells.

If a file does not exist it is skipped.

share|improve this answer
    
So there is no way to see exactly which file(s)? I just have to sort of know what might be likely? For example in this case the shell seems to be bash and uname returns SunOS. But there is no .bash_profile or .bashrc. There are .profile, local.profile, local.login, local.cshrc. What do I use? Are the files you mention simply missing and I should create them? Or would they not be read and I need to use one of these already here? Also, what's the difference between login shells and all shells? –  Svish Feb 6 '13 at 11:11
    
For bash, you would use .bashrc and .bash_profile or.profile. I do not know what local.profile, local.login and local.cshrc do, but the last one is most probably csh-specific. –  user49740 Feb 6 '13 at 11:15
    
So to make a "global" change to $PATH for example, I would have to add my change to both ~/.bashrc and one of ~/.bash_profile, ~/.bash_login and ~/.profile? –  Svish Feb 6 '13 at 11:33
    
If "global" means "for this user", then yes. However, the profile usually sources ~/.bashrc, so adding the change to ~/.bashrc would be enough. –  user49740 Feb 6 '13 at 11:43

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.