Is /etc/paths read by every shell that I run in OS X? For example, if I use zsh, will it parse /etc/path to populate $PATH?
What exactly is the sequence that OS X follows to populate $PATH? Does it do it differently than other Unices?
The OSX devs have implemented their own way of setting up the $PATH which is different from all other Unices as far as I know. They use a program called path_helper which will read /etc/paths and the files in /etc/path.d and modify the user's default $PATH accordingly.
According to this, the $PATH is only set this way for login shells. This is probably why iTerminal starts login shells by default (I've always wondered why they chose that).
According to the same source, path_helper is run from /etc/profile and /etc/csh.login which should affect
bash login shellscsh login shellszsh login shells (should read /etc/profile)/etc/profile which should be most login shells.
/etc/path:). This is not a standard *nix thing so that file is probably called from one of the standard ones. Trygrep path /etc/bash.bashrc /etc/profile /etc/zsh/*that should return the line that calls/etc/path.