#!/usr/bin/perl -w
#
# pbsdcp -- Distributed copy command for the PBS environment
# Copyright 2006 Ohio Supercomputer Center
# Revision info:
# $HeadURL$
# $Revision$
# $Date$
#
# Usage:  pbsdcp [-g|-s] [options] srcfile [...srcfiles...] target
#
# Options:
#  -g   gather mode
#  -s   scatter mode (default)
#
#  -h   print a help message
#  -p   preserve modification times and permissions
#  -r   recursive copy
if ( ! $ENV{"PBS_ENVIRONMENT"} || 
     ( $ENV{"PBS_ENVIRONMENT"} ne "PBS_BATCH" && 
       $ENV{"PBS_ENVIRONMENT"} ne "PBS_INTERACTIVE" ) || 
     $ARGV[0] eq "-h" || $#ARGV < 1 )
{
    if ( ! $ENV{"PBS_ENVIRONMENT"} ||
	 ( $ENV{"PBS_ENVIRONMENT"} ne "PBS_BATCH" &&
	   $ENV{"PBS_ENVIRONMENT"} ne "PBS_INTERACTIVE" ) )
    {
	warn "$0:  Not running withing a PBS job, exiting.\n\n";
    }
    print <<EOH
$0 -- Distributed copy command for the PBS environment

Usage:  pbsdcp [-g|-s|-h] [options] srcfile [...srcfiles...] target

Options:
  -g   gather mode
  -s   scatter mode (default)
  -h   print this help message

  -p   preserve modification times and permissions
  -r   recursive copy
EOH
}
else
{
    # Rewrite the target name if it's a relative path
    $target=pop(@ARGV);
    if ( $target =~ m:^[^/]: )
    {
        $pwd = `pwd`;
        chop($pwd);
        $newtarget = $pwd . "/" . $target;
        $target = $newtarget;
    }

    # Handle -g and -s
    $gather=0;
    if ( $ARGV[0] eq "-g" )
    {
        shift(@ARGV);
        $gather=1;
    }
    elsif ( $ARGV[0] eq "-s" )
    {
        shift(@ARGV);
        $gather=0;
    }

    # Do the heavy lifting
    if ( $gather==1 )
      {
	$pwd=`pwd`;
	chop($pwd);
	# keep the exec'ed local shell from trying to expand wildcards
	foreach $arg ( @ARGV )
	  {
	    $arg =~ s/([\[\]\{\}\(\)\*\?\ ])/\\$1/g;
	    push(@NEWARGV,$arg);
	  }
	exec("all -pj cd $pwd \\; cp @NEWARGV $target\n");
      }
    else # scatter -- default
      {
	$sharedfs = "^/(gpfs|lustre|pvfs|home|[a-z])/";
	# if the target is a known shared file system, just use cp
	if ( $target =~ $sharedfs )
	  {
	    exec("cp @ARGV $target");
	  }
	else
	  {
	    $mpiexec = `which mpiexec 2>/dev/null`;
	    chomp($mpiexec);
	    $scatter = `which pbsdcp-scatter 2>/dev/null`;
	    chomp($scatter);
	    # use pbsdcp-scatter if available
	    if ( length($mpiexec)>0 && length($scatter)>0 )
	      {
		exec("mpiexec -pernode pbsdcp-scatter @ARGV $target");
	      }
	    # if pbsdcp-scatter is not available but there's a node file, use rcp
	    elsif ( defined($ENV{'PBS_NODEFILE'}) && -s $ENV{'PBS_NODEFILE'} )
	      {
		open(NODES,"uniq ".$ENV{'PBS_NODEFILE'}." |");
		@node=<NODES>;
		chop(@node);
		if ( $#node>0 )
		  {
		    for ( $i=0 ; $i<=$#node; $i++ )
		      {
			if ( ($pid[$i]=fork)==0 )
			  {
			    exec("rcp @ARGV $node[$i]:$target\n");
			  }
		      }
		    for ( $i=0 ; $i<=$#node; $i++ )
		      {
			waitpid($pid[$i],0);
		      }
		  }
		else
		  {
		    exec("cp @ARGV $target");
		  }
	      }
	    # if all else fails, just use cp
	    else
	      {
		exec("cp @ARGV $target");
	      }
	  }
      }
}