source: vendor/diffutils/2.8.1/lib/prepargs.c

Last change on this file was 2556, checked in by bird, 19 years ago

diffutils 2.8.1

File size: 2.7 KB
Line 
1/* Parse arguments from a string and prepend them to an argv.
2
3 Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2, or (at your option)
8 any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
18 02111-1307, USA. */
19
20/* Written by Paul Eggert <eggert@twinsun.com>. */
21
22#ifdef HAVE_CONFIG_H
23# include <config.h>
24#endif
25#include "prepargs.h"
26#include <string.h>
27#include <sys/types.h>
28#include <xalloc.h>
29
30#include <ctype.h>
31
32/* IN_CTYPE_DOMAIN (C) is nonzero if the unsigned char C can safely be given
33 as an argument to <ctype.h> macros like "isspace". */
34#ifdef STDC_HEADERS
35# define IN_CTYPE_DOMAIN(c) 1
36#else
37# define IN_CTYPE_DOMAIN(c) ((c) <= 0177)
38#endif
39
40#define ISSPACE(c) (IN_CTYPE_DOMAIN (c) && isspace (c))
41
42/* Find the white-space-separated options specified by OPTIONS, and
43 using BUF to store copies of these options, set ARGV[0], ARGV[1],
44 etc. to the option copies. Return the number N of options found.
45 Do not set ARGV[N]. If ARGV is zero, do not store ARGV[0] etc.
46 Backslash can be used to escape whitespace (and backslashes). */
47static int
48prepend_args (char const *options, char *buf, char **argv)
49{
50 char const *o = options;
51 char *b = buf;
52 int n = 0;
53
54 for (;;)
55 {
56 while (ISSPACE ((unsigned char) *o))
57 o++;
58 if (!*o)
59 return n;
60 if (argv)
61 argv[n] = b;
62 n++;
63
64 do
65 if ((*b++ = *o++) == '\\' && *o)
66 b[-1] = *o++;
67 while (*o && ! ISSPACE ((unsigned char) *o));
68
69 *b++ = '\0';
70 }
71}
72
73/* Prepend the whitespace-separated options in OPTIONS to the argument
74 vector of a main program with argument count *PARGC and argument
75 vector *PARGV. */
76void
77prepend_default_options (char const *options, int *pargc, char ***pargv)
78{
79 if (options)
80 {
81 char *buf = xmalloc (strlen (options) + 1);
82 int prepended = prepend_args (options, buf, (char **) 0);
83 int argc = *pargc;
84 char * const *argv = *pargv;
85 char **pp = (char **) xmalloc ((prepended + argc + 1) * sizeof *pp);
86 *pargc = prepended + argc;
87 *pargv = pp;
88 *pp++ = *argv++;
89 pp += prepend_args (options, buf, pp);
90 while ((*pp++ = *argv++))
91 continue;
92 }
93}
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