#!/usr/bin/mawk -We
# *********************************************************************
#  Written by and copyright Carlo Strozzi <carlos@linux.it>.
#
#  union: concatenate multiple NoSQL tables and print them to stdout in
#  the form of one larger table. The input tables must all have the
#  same No. of columns, i.e. they must be ``union compatible''.
#  Copyright (C) 2001 Carlo Strozzi <carlos@linux.it>
# 
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
# 
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
# 
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
#  2001-01-15 Initial release
#  2001-04-18 Added inline help
#
#  $Id$
# *********************************************************************

BEGIN {
  NULL = ""; FS = OFS = "\t"; nr = 1

  while (ARGV[++i] != NULL) {
    if (ARGV[i] == "-N" || ARGV[i] == "--no-header") no_hdr = 1
    else if (ARGV[i] == "-a" || ARGV[i] == "--xargs") h_table = ARGV[++i]
    else if (ARGV[i] == "-h" || ARGV[i] == "--help") {
       system("grep -v '^#' @NOSQLPATH@/nosql/help/union.txt")
       rc = 1
       exit(rc)
    }
    else argv[++j] = ARGV[i]
  }

  # Move argv[] back onto ARGV[].

  while (++k <= j) { ARGV[k] = argv[k] }

  ARGC = k				# Set the new arg count.
}

#
# Main loop
#

NR == 1 {old_filename = FILENAME}

NR < 3 {

   if (no_hdr) next
   if (h_table != NULL && FILENAME != h_table) next

}

FILENAME == old_filename {

   if (++nr > 1) print
   next
}

{nr = 0; old_filename = FILENAME}

#
# End of program.
#
