#!/usr/bin/perl -n
# tsc-permute: permute each word of input
use subs qw( _permute );
permute(split);

{
  my @perm;
  my @unperm;

  sub permute {
    @perm = ();
    @unperm = @_;
    _permute;
  }

  sub _permute {
    if (@unperm) {
      push @perm, pop @unperm;
      foreach (1..@perm) {
        push @perm, shift @perm;
        _permute;
      }
      push @unperm, pop @perm;
    }
    else {
      print "@perm\n";
    }
  }
}