1/*	$NetBSD$	*/
2
3/* Parse arguments from a string and prepend them to an argv.
4
5   Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 2, or (at your option)
10   any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program; if not, write to the Free Software
19   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
20   02111-1307, USA.  */
21
22/* Written by Paul Eggert <eggert@twinsun.com>.  */
23
24#ifdef HAVE_CONFIG_H
25# include <config.h>
26#endif
27#include "prepargs.h"
28#include <string.h>
29#include <sys/types.h>
30#include <xalloc.h>
31
32#include <ctype.h>
33
34/* IN_CTYPE_DOMAIN (C) is nonzero if the unsigned char C can safely be given
35   as an argument to <ctype.h> macros like "isspace".  */
36#ifdef STDC_HEADERS
37# define IN_CTYPE_DOMAIN(c) 1
38#else
39# define IN_CTYPE_DOMAIN(c) ((c) <= 0177)
40#endif
41
42#define ISSPACE(c) (IN_CTYPE_DOMAIN (c) && isspace (c))
43
44/* Find the white-space-separated options specified by OPTIONS, and
45   using BUF to store copies of these options, set ARGV[0], ARGV[1],
46   etc. to the option copies.  Return the number N of options found.
47   Do not set ARGV[N].  If ARGV is zero, do not store ARGV[0] etc.
48   Backslash can be used to escape whitespace (and backslashes).  */
49static int
50prepend_args (char const *options, char *buf, char **argv)
51{
52  char const *o = options;
53  char *b = buf;
54  int n = 0;
55
56  for (;;)
57    {
58      while (ISSPACE ((unsigned char) *o))
59	o++;
60      if (!*o)
61	return n;
62      if (argv)
63	argv[n] = b;
64      n++;
65
66      do
67	if ((*b++ = *o++) == '\\' && *o)
68	  b[-1] = *o++;
69      while (*o && ! ISSPACE ((unsigned char) *o));
70
71      *b++ = '\0';
72    }
73}
74
75/* Prepend the whitespace-separated options in OPTIONS to the argument
76   vector of a main program with argument count *PARGC and argument
77   vector *PARGV.  */
78void
79prepend_default_options (char const *options, int *pargc, char ***pargv)
80{
81  if (options)
82    {
83      char *buf = xmalloc (strlen (options) + 1);
84      int prepended = prepend_args (options, buf, (char **) 0);
85      int argc = *pargc;
86      char * const *argv = *pargv;
87      char **pp = (char **) xmalloc ((prepended + argc + 1) * sizeof *pp);
88      *pargc = prepended + argc;
89      *pargv = pp;
90      *pp++ = *argv++;
91      pp += prepend_args (options, buf, pp);
92      while ((*pp++ = *argv++))
93	continue;
94    }
95}
96