#!/usr/bin/perl
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Reads any number of file names from the command line, then split()s
# STDIN on tabs and writes them to those files. Example usage:
#
# paste file1 file2 file3 ... | split2files file1.new file2.new file3.new.gz ...
#
# If there are more fields on STDIN that files on the command-line, the extra
# fields are silently discarded.
#
# A common usage scenario is to paste together parallel lines and do some filtering,
# then write out to a new set of files (thus retaining parallelization).

use FileHandle;

my @fh;
$| = 1;   # don't buffer output

if (@ARGV < 0) {
  print "Usage: cat tabbed-file | split2files file1 [file2 [file3 ...]]\n";
  exit;
}

my @fh = map { get_filehandle($_) } @ARGV;
@ARGV = ();

while (my $line = <>) {
  chomp($line);
  my (@fields) = split(/\t/, $line);
  
  map { print {$fh[$_]} "$fields[$_]\n" } (0..$#fh);
}

sub get_filehandle {
    my $file = shift;

    if ($file eq "-") {
	return *STDOUT;
    } else {
	local *FH;
	open FH, ">$file" or die "can't open '$file' for writing";
	return *FH;
    }
}