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 duplicated when you source your cshrc file multiple times, how do you prevent the duplication?

EDIT: This is one unclean way of doing it:

set localpaths = ( . $otherpaths ) echo ${path} | egrep -i '$localpaths' >& /dev/null if ($status != 0) then     set path = ( . $otherpaths $path ) endif 

Answer 1

you can use the following Perl script to prune paths of duplicates.

---

#!/usr/bin/perl # # ^^ ensure this is pointing to the correct location. # # Title:    SLimPath # Author:   David 'Shoe Lace' Pyke <[e-mail] > #   :   Tim Nelson  # Purpose: To create a slim version of my envirnoment path so as to eliminate #       duplicate entries and ensure that the '.' path was last. # Date Created: April 1st 1999 # Revision History: #   01/04/99: initial tests.. didn't wok verywell at all #       : retreived path throught '$ENV' call #   07/04/99: After an email from Tim Nelson <[e-mail]> got it to #         work. #       : used 'push' to add to array #       : used 'join' to create a delimited string from a list/array. #   16/02/00: fixed cmd-line options to look/work better #   25/02/00: made verbosity level-oriented # #  use Getopt::Std;  sub printlevel;  $initial_str = ''; $debug_mode = ''; $delim_chr = ':'; $opt_v = 1;  getopts('v:hd:l:e:s:');  OPTS: {     $opt_h && do { print '\n$0 [-v level] [-d level] [-l delim] ( -e varname | -s strname | -h )'; print '\nWhere:'; print '\n   -h  This help'; print '\n   -d  Debug level'; print '\n   -l  Delimiter (between path vars)'; print '\n   -e  Specify environment variable (NB: don't include \$ sign)'; print '\n   -s  String (ie. $0 -s \$PATH:/looser/bin/)'; print '\n   -v  Verbosity (0 = quiet, 1 = normal, 2 = verbose)'; print '\n';         exit;     };     $opt_d && do {         printlevel 1, 'You selected debug level $opt_d\n';         $debug_mode = $opt_d;     };     $opt_l && do {         printlevel 1, 'You are going to delimit the string with \'$opt_l\'\n';         $delim_chr = $opt_l;     };     $opt_e && do {         if($opt_s) { die 'Cannot specify BOTH env var and string\n'; }         printlevel 1, 'Using Environment variable \'$opt_e\'\n';         $initial_str = $ENV{$opt_e};     };     $opt_s && do {         printlevel 1, 'Using String \'$opt_s\'\n';         $initial_str = $opt_s;     }; }  if( ($#ARGV != 1) and !$opt_e and !$opt_s){     die 'Nothing to work with -- try $0 -h\n'; }  $what = shift @ARGV; # Split path using the delimiter @dirs = split(/$delim_chr/, $initial_str);  $dest; @newpath = (); LOOP: foreach (@dirs){     # Ensure the directory exists and is a directory     if(! -e ) { printlevel 1, '$_ does not exist\n'; next; }     # If the directory is ., set $dot and go around again     if($_ eq '.') { $dot = 1; next; }  #   if ($_ ne `realpath $_`){ #           printlevel 2, '$_ becomes '.`realpath $_`.'\n'; #   }     undef $dest;     #$_=Stdlib::realpath($_,$dest);     # Check for duplicates and dot path     foreach $adir (@newpath) { if($_ eq $adir) {          printlevel 2, 'Duplicate: $_\n';         next LOOP;      }}      push @newpath, $_; }  # Join creates a string from a list/array delimited by the first expression print join($delim_chr, @newpath) . ($dot ? $delim_chr.'.\n' : '\n');  printlevel 1, 'Thank you for using $0\n'; exit;  sub printlevel {     my($level, $string) = @_;      if($opt_v >= $level) {         print STDERR $string;     } } 

---

i hope thats useful.