How to keep from duplicating path variable in csh

Question

It is typical to have something like this in your cshrc file for setting the path:

set path = ( . $otherpath $path )

but, the path gets dup

Answer 1

Using sed(1) to remove duplicates.

$ PATH=$(echo $PATH | sed -e 's/$/:/;s/^/:/;s/:/::/g;:a;s#\(:[^:]\{1,\}:\)\(.*\)\1#\1\2#g;ta;s/::*/:/g;s/^://;s/:$//;')

This will remove the duplicates after the first instance, which may or may not be what you want, e.g.:

$ NEWPATH=/bin:/usr/bin:/bin:/usr/local/bin:/usr/local/bin:/bin
$ echo $NEWPATH | sed -e 's/$/:/; s/^/:/; s/:/::/g; :a; s#\(:[^:]\{1,\}:\)\(.*\)\1#\1\2#g; t a; s/::*/:/g; s/^://; s/:$//;'
/bin:/usr/bin:/usr/local/bin
$

Enjoy!