iankelling.org Git - distro-setup/blob - path_add-function

   1 #!/bin/bash
   2 # no bashisms so it can be used in debian profile run by dash
   3 # --start adds to start of path, which will give it highest priority
   4 # --ifexists will add to path only if the directory exists
   5 path_add() {
   6     local found x y z ifexists start loop
   7     ifexists=false
   8     start=false
   9     loop=true
  10     # portable substring matching is ugly http://mywiki.wooledge.org/BashFAQ/041
  11     while $loop; do
  12         case $1 in
  13             --*)
  14                 if [ "$1" = --start ]; then
  15                     start=true
  16                 elif [ "$1" = --ifexists ]; then
  17                     ifexists=true
  18                 fi
  19                 shift
  20                 ;;
  21             *)
  22                 loop=false
  23                 ;;
  24         esac
  25     done
  26     for x in "$@"; do
  27         found=false
  28         IFS=:
  29         for y in $PATH; do
  30             [ "$x" = "$y" ] && found=true
  31         done
  32         unset IFS
  33         if ! $found; then
  34             if ! $ifexists || [ -d "$x" ]; then
  35                 if [ ! "$PATH" ]; then
  36                     PATH="$x"
  37                 elif $start; then
  38                     PATH="$x:$PATH"
  39                 else
  40                     PATH="$PATH:$x"
  41                 fi
  42             fi
  43         fi
  44     done
  45 }