source: proiecte/pmake3d/make3d_original/Make3dSingleImageStanford_version0.1/third_party/vrippack-0.31/src/pvrip/permute @ 37

#!/usr/bin/perl

# permute a b c ...
# reorders the words on each line
# good for rearranging/selecting columns from ls, etc.
# first word is word 0
# e.g. "echo a b c d e f"
#       a b c d e f
# e.g. "echo a b c d e f | permute 4 2"
#       e c
#

# check usage
if ($#ARGV == -1 || substr($ARGV[0],0,1) eq "-") {
    print STDERR "Usage:  permute <col1> [col2] [col3]...\n";
    print STDERR " e.g. \"echo a b c d e f\"\n";
    print STDERR "       a b c d e f\n";
    print STDERR " e.g. \"echo a b c d e f | permute 4 2\"\n";
    print STDERR "       e c\n";
    exit(-1);
}
    


# split on whitespace
while (<STDIN>) {
    @words = split(' ', $_);
    for ($i=0; $i <= $#ARGV; $i++) {
        print $words[$ARGV[$i]]." ";
    }
    print "\n";
}