whence

Ever wonder if a command or file is in your path?  Here’s a handy perl script to answer that question:

#!/usr/bin/perl
##################################################################
## whence                                                       ##
##                                                              ##
## Search PATH for a filename.  If you're wondering where       ##
## a file or command is being sourced from, or if you want to   ##
## know whether a file is in your path:                         ##              
##                                                              ## 
## whence <filename>                                            ##                 
##                                                              ## 
## CLH 5-Oct-2010                                               ## 
##################################################################

if (@ARGV != 1) {
    print "\nusage: whence <filename>\n\n";
    print "Search PATH for specified filename " .
             "and return all occurrences.\n\n";
    exit 0;
} 

use constant TRUE=>1;
use constant FALSE=>0;

$p=shift;
$found = FALSE; 

foreach $path (split(/:/,$ENV{'PATH'})) {
  $path =~ s/\/$//;
  $find = $path . '/' . $p;
  if (-e $find) {
      print "$find\n";
      $found = TRUE;
  }
}

if ($found == FALSE){
    print "$p was not found in PATH.\n"; 
} 

exit 1;