#!/usr/bin/mawk -We
# *********************************************************************
#  Written by and copyright Carlo Strozzi <carlos@linux.it>.
#
#  unique: make a table unique on the key field.
#  Copyright (C) 2001-2003 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.
#
# *********************************************************************
#  $Id: unique,v 1.2 2003/03/17 10:10:46 carlo Exp $

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

  # Get local settings.
  nosql_install = ENVIRON["NOSQL_INSTALL"]
  stdout = ENVIRON["NOSQL_STDOUT"]
  stderr = ENVIRON["NOSQL_STDERR"]

  # Set default values if necessary.
  if (nosql_install == NULL) nosql_install = "/usr/local/nosql"
  if (stdout == NULL) stdout = "/dev/stdout"
  if (stderr == NULL) stderr = "/dev/stderr"

  while (ARGV[++i] != NULL) {
     if (ARGV[i] == "-i" || ARGV[i] == "--input") i_file = ARGV[++i]
     else if (ARGV[i] == "-o" || ARGV[i] == "--output") o_file = ARGV[++i]
     else if (ARGV[i] == "-l" || ARGV[i] == "--last") last = 1
     else if (ARGV[i] == "-N" || ARGV[i] == "--no-header") no_hdr = 1
     else if (ARGV[i] == "-h" || ARGV[i] == "--help") {
	system("grep -v '^#' " nosql_install "/help/unique.txt")
	rc = 1
	exit(rc)
     }
  }

  ARGC = 1					# Fix argv[]

  if (o_file == NULL) o_file = stdout
  if (i_file != NULL) { ARGV[1] = i_file; ARGC = 2 }
}

#
# Main loop
#

NR == 1 {
   if (!no_hdr) print > o_file
   next
}

#
# Next code loads the input table entirely into memory, so be warned.
#

{
   if (last) a_rdb[$1] = $0
   else {
      if (a_rdb[$1] == NULL) a_rdb[$1] = $0 
   }
}

END {
   if (rc) exit(rc)
   for(i in a_rdb) print a_rdb[i] > o_file
}

#
# End of program.
#
