1 /* prepend_args.c - utilility programs for manpiulating argv[]
2 Copyright (C) 1999 Free Software Foundation, Inc.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
7 any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
17 02111-1307, USA. */
18
19 /* $FreeBSD: src/contrib/diff/prepend_args.c,v 1.1 1999/11/26 02:51:44 obrien Exp $ */
20
21
22 #ifdef HAVE_CONFIG_H
23 # include "config.h"
24 #endif
25 #include "system.h"
26 #include "prepend_args.h"
27 #include "diff.h"
28
29
30 /* Find the white-space-separated options specified by OPTIONS, and
31 using BUF to store copies of these options, set ARGV[0], ARGV[1],
32 etc. to the option copies. Return the number N of options found.
33 Do not set ARGV[N] to NULL. If ARGV is NULL, do not store ARGV[0]
34 etc. Backslash can be used to escape whitespace (and backslashes). */
35 static int
prepend_args(options,buf,argv)36 prepend_args (options, buf, argv)
37 char const *options;
38 char *buf;
39 char **argv;
40 {
41 char const *o = options;
42 char *b = buf;
43 int n = 0;
44
45 for (;;)
46 {
47 while (ISSPACE ((unsigned char) *o))
48 o++;
49 if (!*o)
50 return n;
51 if (argv)
52 argv[n] = b;
53 n++;
54
55 do
56 if ((*b++ = *o++) == '\\' && *o)
57 b[-1] = *o++;
58 while (*o && ! ISSPACE ((unsigned char) *o));
59
60 *b++ = '\0';
61 }
62 }
63
64 /* Prepend the whitespace-separated options in OPTIONS to the argument
65 vector of a main program with argument count *PARGC and argument
66 vector *PARGV. */
67 void
prepend_default_options(options,pargc,pargv)68 prepend_default_options (options, pargc, pargv)
69 char const *options;
70 int *pargc;
71 char ***pargv;
72 {
73 if (options)
74 {
75 char *buf = xmalloc (strlen (options) + 1);
76 int prepended = prepend_args (options, buf, (char **) NULL);
77 int argc = *pargc;
78 char * const *argv = *pargv;
79 char **pp = (char **) xmalloc ((prepended + argc + 1) * sizeof *pp);
80 *pargc = prepended + argc;
81 *pargv = pp;
82 *pp++ = *argv++;
83 pp += prepend_args (options, buf, pp);
84 while ((*pp++ = *argv++))
85 continue;
86 }
87 }
88