Subversion Repositories planix.SVN

/* prepend_args.c - utilility programs for manpiulating argv[]

   Copyright (C) 1999 Free Software Foundation, Inc.

   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, 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., 59 Temple Place - Suite 330, Boston, MA

   02111-1307, USA.  */

/* $FreeBSD: src/contrib/diff/prepend_args.c,v 1.1 1999/11/26 02:51:44 obrien Exp $ */

#ifdef HAVE_CONFIG_H

# include "config.h"

#endif

#include "system.h"

#include "prepend_args.h"

#include "diff.h"

/* Find the white-space-separated options specified by OPTIONS, and

   using BUF to store copies of these options, set ARGV[0], ARGV[1],

   etc. to the option copies.  Return the number N of options found.

   Do not set ARGV[N] to NULL.  If ARGV is NULL, do not store ARGV[0]

   etc.  Backslash can be used to escape whitespace (and backslashes).  */

static int

prepend_args (options, buf, argv)

     char const *options;

     char *buf;

     char **argv;

{

  char const *o = options;

  char *b = buf;

  int n = 0;

  for (;;)

    {

      while (ISSPACE ((unsigned char) *o))

	o++;

      if (!*o)

	return n;

      if (argv)

	argv[n] = b;

      n++;

      do

	if ((*b++ = *o++) == '\\' && *o)

	  b[-1] = *o++;

      while (*o && ! ISSPACE ((unsigned char) *o));

      *b++ = '\0';

    }

}

/* Prepend the whitespace-separated options in OPTIONS to the argument

   vector of a main program with argument count *PARGC and argument

   vector *PARGV.  */

void

prepend_default_options (options, pargc, pargv)

     char const *options;

     int *pargc;

     char ***pargv;

{

  if (options)

    {

      char *buf = xmalloc (strlen (options) + 1);

      int prepended = prepend_args (options, buf, (char **) NULL);

      int argc = *pargc;

      char * const *argv = *pargv;

      char **pp = (char **) xmalloc ((prepended + argc + 1) * sizeof *pp);

      *pargc = prepended + argc;

      *pargv = pp;

      *pp++ = *argv++;

      pp += prepend_args (options, buf, pp);

      while ((*pp++ = *argv++))

	continue;

    }

}