Where does $PATH get set in OS X 10.6 Snow Leopard?

Question

I type echo $PATH on the command line and get

/opt/local/bin:/opt/local/sbin:/Users/andrew/bin:/usr/local/bin:/usr/local/mysql/bin:/usr/local/pear/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/opt/local/bin:/usr/local/git/bin

I'm wondering where this is getting set since my .bash_login file is empty.

I'm particularly concerned that, after installing MacPorts, it installed a bunch of junk in /opt. I don't think that directory even exists in a normal Mac OS X install.

Update: Thanks to jtimberman for correcting my echo $PATH statement

Answer 1

When bash starts it reads the following files every time you login. For the purposes of OS X, this means every time you open a new Terminal window.

/etc/profile
~/.bash_profile
~/.bash_login   (if .bash_profile does not exist)
~/.profile      (if .bash_login does not exist)

When you start a new shell by typing bash on the command line, it reads .bashrc

OS X also uses ~/.MacOSX/environment.plist to set more environment variables, including paths if necessary.

Finally, /etc/paths and /etc/paths.d are read by the shell too.

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/opt/local/bin etc. are added in ~/.tcshrc by MacPorts. Also be sure to look in ~/.cshrc.

Answer 2

Take a look at the file /etc/paths, which is used by /usr/libexec/path_helper, which is used by /etc/profile.

For MacPorts, use sudo /etc/paths/opt/local/bin and reopen the terminal window.

Answer 3

Seriously, Leopard gave us a new way to add path. Just create a file containing the path part you want to add, and put it in /etc/paths.d

A quick example of doing this in one step is:

echo "/some/path/to/add" >> /etc/paths.d/somefilename

Otherwise, you can just go to /etc/paths.d and put the file there directly. Either way, any path parts in the files in that directory will be appended to the default path.

This also works for manpath.

Here's a link to more details:

ars technica: how do i add something to PATH in snow leopard?

On a 2nd note: MacPorts puts everything into the opt directory precisely because it isn't used by Apple's stuff. That way it won't conflict. Their guide (excellently written, BTW) has an explanation of why it uses opt and how to change that default if you'd like.

MacPorts Guide

Answer 4

To show your path, echo $PATH.

echo $PATH

To set your path, edit ~/.bash_profile, not ~/.bash_login.

Answer 5

There's also the path as determined by ssh.

Compare echo $PATH to ssh localhost 'echo $PATH'. Since ssh does not read /etc/profile, /usr/libexec/path_helper doesn't run and thus /etc/paths is skipped. Now try ssh localhost 'source /etc/profile; echo $PATH'. The paths should be closer. The remaining differences will likely be due to path modification in your .bash_profile (which is also skipped by ssh) and .bashrc (which is read by ssh).

If you want your ssh path to be similar to your normal terminal path, you could add source /etc/profile to your .bashrc.

Answer 6

It could be defined in either:

• System variables - /etc/paths
• User variables - see @Steve Folly's explanation

Answer 7

Regarding docs for /usr/libexec/path_helper utility, initial components for $PATH was taken from /etc/paths and by default looks like

/usr/bin
/bin
/usr/sbin
/sbin
/usr/local/bin

for OS-X Snow Leopard

Answer 8

Actually it is stored in your .profile file instead of .bash_login and it is common that MacPorts will use this instead of the .bash_login file.

Also The /opt directory is usually created by MacPorts and it stores its files in this folder.