Question

When I do ‘open .profile’ in the terminal I have the following:

export PATH=$PATH:/usr/local/git/bin 

Now I installed node.js for Mac and it says,

Make sure that /usr/local/bin is in your $PATH.

How can I add /usr/local/bin to export PATH=$PATH:/usr/local/git/bin?

Answer 1

The PATH variable holds a list of directories separated by colons, so if you want to add more than one directory, just put a colon between them:

export PATH=$PATH:/usr/local/git/bin:/usr/local/bin

That syntax works in any Bourne-compatible shell (sh, ksh, bash, zsh…). But zsh, which is the default shell in recent versions of MacOS, also exposes the PATH another way – as a variable named (lowercase) $path, which is an array instead of a single string. So you can do this instead:

path+=(/usr/local/git/bin /usr/local/bin) 

In either case, you may want to check to make sure the directory isn’t already in the PATH before adding it. Here’s what that looks like using the generic syntax:

for dir in /usr/local/git/bin /usr/local/bin; do
   case "$PATH" in 
     $dir:*|*:$dir:*|*:$dir) :;; # already there, do nothing
     *) PATH=$PATH:$dir          # otherwise add it
   esac
done

And here’s a zsh-specific version:

for dir in /usr/local/git/bin /usr/local/bin; do
  if (( ${path[(i)$dir]} > $#path )); then
    path+=($dir)
  fi
done

But in Zsh you can also just mark the array vars as accepting only unique entries:

typeset -TU PATH path

and even make your own pathlike variables mirrored in arrays:

typeset -TU PYTHONPATH pythonpath