What is the equivalent of pathmunge() in csh?

Question

In bash, a common function implemented in e.g. /etc/bashrc is pathmunge(), which appends or prepends a path to PATH if it isn't already listed among the elements in PATH.

Example:

$ echo $PATH
/bin:/usr/bin
$ pathmunge /home/me/bin
$ echo $PATH
/home/me/bin:/bin:/usr/bin
$ pathmunge /home/me/bin
$ echo $PATH
/home/me/bin:/bin:/usr/bin

The naive way to add a path would be as follow:

$ echo $PATH
/bin:/usr/bin
$ PATH=/home/me/bin:$PATH
$ echo $PATH
/home/me/bin:/bin:/usr/bin
$ PATH=/home/me/bin:$PATH
$ echo $PATH
/home/me/bin:/home/me/bin:/bin:/usr/bin

I know very little about csh, and I just want to do this simple thing: add a path to a list if it's not already there. I am aware that csh uses path rather than PATH and that is is a proper csh array.

Maybe csh has some array function like if !(foobar in $path) then blah that makes a function like pathmunge() unnecessary. In that case, that is the correct answer.

Answer 1

The official workaround for missing array management in csh is to use the Modules system (environment-modules package on Debian).

Answer 2

I finally went with the solution of shelling into bash, because it doesn't seem possible to solve this within the ''csh'' language.

~/bin/munge_echo:

#!/bin/bash

function munge() {
  case ":$1:" in
    *:$2:*) echo "$1" ;;
    ::) echo "$2" ;;
    *) echo "$2:$1" ;;
  esac
}

munged="$1"

shift

while [ -n "$1" ]; do
  munged="$(munge "$munged" "$1")"
  shift
done

echo "$munged"

~/.csh:

setenv PATH `~/bin/munge_echo "$PATH" ~/.local/bin ~/bin`