u

script_nuance/addpath.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# usage: . addpath.sh new_path
+
+# this script requires a normalized $PATH: 
+# 1. each path except the last one must be followed by ":" without any whitespace; 
+# 2. each path is NOT finished by "/"
+# besides, the input parameter $1 is NOT finished by "/".
+# Purpose of the normalization is to match $ENV{NEWPATH}(:\|$)
+
+# it must be explicitly exported because Perl only add environment variables to %ENV, not those shell variables:
+export NEWPATH=$1  
+# on windows, we must use /usr/bin/perl from cygwin, because ActivePerl doesn't work on following line:
+if [ 'no' == `/usr/bin/perl -e 'if ($ENV{PATH} =~ m|$ENV{NEWPATH}(:\|$)|) {exec "echo yes"} else {exec "echo no"}'` ]
+then
+    export PATH=$1:$PATH
+fi