MacOS – Understanding How $PATH Variable is Built

bashmacospath

I've recently installed Homebrew on my Mac and it's complaining that /usr/bin occurs before /usr/local/bin in my $PATH variable, meaning that system-provided programs will be used instead of those installed with Homebrew.

My .bashrc is configured in a set of separate files, as per this screencast. This means that ~/.bash_profile looks like this:

if [ -f ~/.bashrc ];
then
  source ~/.bashrc
fi

~/.bashrc looks like this:

source ~/bin/dotfiles/bashrc

and ~/bin/dotfiles/bashrc looks like this:

. ~/bin/dotfiles/bash/env
. ~/bin/dotfiles/bash/config
. ~/bin/dotfiles/bash/aliases

~/bin/dotfiles/bash/env, which is where I set my $PATH variable, looks like this:

export EDITOR="kom"
export PATH=some/path/at/start:usr/local/bin:/Users/jim/pear/bin:~/bin:/Users/jim/.gem/ruby/1.8/bin:/Users/jim/bin/bashscripts:some/path/at/end:$PATH

I've added some/path/at/start and some/path/at/end for debugging purposes, since when I try echo $PATH I get this:

/opt/local/bin:/opt/local/sbin:/Users/jim/bin:/opt/local/bin:/opt/local/sbin:some/path/at/start:usr/local/bin:/Users/jim/pear/bin:/Users/jim/bin:/Users/jim/.gem/ruby/1.8/bin:/Users/jim/bin/bashscripts:some/path/at/end:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin

That is, there's a load of other stuff being loaded into the $PATH variable that I can't control in the configuration I've outlined above. Any ideas as to where this stuff is loaded from, so that I can go about changing it and moving /usr/local/bin before /usr/bin?

Best Answer

If you fix the typo in your PATH assignment and replace usr/local/bin with /usr/local/bin Homebrew should stop complaining.

The other stuff (/opt/local/...) is definitively added somewhere later during shell initialization (meaning after source ~/.bashrc or after . ~/bin/dotfiles/bash/env). You will have to look through the different files (or grep for /opt/local or PATH.*PATH) to see where it happens (and why).

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