path-add

#!/bin/bash
set -euf -o pipefail
out () { printf %s\\n "$*" ; }

##
# Add path(s) to the PATH environment variable
#
# Usage: path-add [-i] [-q] paths...
#
#   -i: Insert at the front, instead of the end
#   -q: Don't print any error messages
#
# From http://pastie.org/591350
#
# Contact: Joel Parker Henderson (joel@joelparkerhenderson.com)
# License: GPL
# Updated: 2015-01-25
##

ap_prefix=0
ap_quiet=0
OPTIND=1
while getopts iq var
do
    case "$var" in
        i) ap_prefix=1 ;;
        q) ap_quiet=1 ;;
    esac
done
shift $(( $OPTIND - 1 ))

for p in "$@"
do
    p=${p%"${p##*[!/]}"} ## remove trailing slashes
    case $p in
        ""|.) continue ;;
    esac
    case :$PATH: in
        *:$p:*) [ $ap_quiet -eq 0 ] && out "addpath: $p already in path" >&2
        continue
        ;;
    esac
    if [ -d "$p" ]
    then
        if [ $ap_prefix -eq 1 ]
        then
            PATH="$p:$PATH"
        else
            PATH="$PATH:$p"
        fi
    else
        [ $ap_quiet -eq 0 ] && out "addpath: $p is not a directory" >&2
    fi
done
export PATH