xref: /plan9/sys/src/ape/cmd/diff/prepend_args.c (revision 0b459c2cb92b7c9d88818e9a2f72e678e5bc4553)
1*0b459c2cSDavid du Colombier /* prepend_args.c - utilility programs for manpiulating argv[]
2*0b459c2cSDavid du Colombier    Copyright (C) 1999 Free Software Foundation, Inc.
3*0b459c2cSDavid du Colombier 
4*0b459c2cSDavid du Colombier    This program is free software; you can redistribute it and/or modify
5*0b459c2cSDavid du Colombier    it under the terms of the GNU General Public License as published by
6*0b459c2cSDavid du Colombier    the Free Software Foundation; either version 2, or (at your option)
7*0b459c2cSDavid du Colombier    any later version.
8*0b459c2cSDavid du Colombier 
9*0b459c2cSDavid du Colombier    This program is distributed in the hope that it will be useful,
10*0b459c2cSDavid du Colombier    but WITHOUT ANY WARRANTY; without even the implied warranty of
11*0b459c2cSDavid du Colombier    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12*0b459c2cSDavid du Colombier    GNU General Public License for more details.
13*0b459c2cSDavid du Colombier 
14*0b459c2cSDavid du Colombier    You should have received a copy of the GNU General Public License
15*0b459c2cSDavid du Colombier    along with this program; if not, write to the Free Software
16*0b459c2cSDavid du Colombier    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
17*0b459c2cSDavid du Colombier    02111-1307, USA.  */
18*0b459c2cSDavid du Colombier 
19*0b459c2cSDavid du Colombier /* $FreeBSD: src/contrib/diff/prepend_args.c,v 1.1 1999/11/26 02:51:44 obrien Exp $ */
20*0b459c2cSDavid du Colombier 
21*0b459c2cSDavid du Colombier 
22*0b459c2cSDavid du Colombier #ifdef HAVE_CONFIG_H
23*0b459c2cSDavid du Colombier # include "config.h"
24*0b459c2cSDavid du Colombier #endif
25*0b459c2cSDavid du Colombier #include "system.h"
26*0b459c2cSDavid du Colombier #include "prepend_args.h"
27*0b459c2cSDavid du Colombier #include "diff.h"
28*0b459c2cSDavid du Colombier 
29*0b459c2cSDavid du Colombier 
30*0b459c2cSDavid du Colombier /* Find the white-space-separated options specified by OPTIONS, and
31*0b459c2cSDavid du Colombier    using BUF to store copies of these options, set ARGV[0], ARGV[1],
32*0b459c2cSDavid du Colombier    etc. to the option copies.  Return the number N of options found.
33*0b459c2cSDavid du Colombier    Do not set ARGV[N] to NULL.  If ARGV is NULL, do not store ARGV[0]
34*0b459c2cSDavid du Colombier    etc.  Backslash can be used to escape whitespace (and backslashes).  */
35*0b459c2cSDavid du Colombier static int
prepend_args(options,buf,argv)36*0b459c2cSDavid du Colombier prepend_args (options, buf, argv)
37*0b459c2cSDavid du Colombier      char const *options;
38*0b459c2cSDavid du Colombier      char *buf;
39*0b459c2cSDavid du Colombier      char **argv;
40*0b459c2cSDavid du Colombier {
41*0b459c2cSDavid du Colombier   char const *o = options;
42*0b459c2cSDavid du Colombier   char *b = buf;
43*0b459c2cSDavid du Colombier   int n = 0;
44*0b459c2cSDavid du Colombier 
45*0b459c2cSDavid du Colombier   for (;;)
46*0b459c2cSDavid du Colombier     {
47*0b459c2cSDavid du Colombier       while (ISSPACE ((unsigned char) *o))
48*0b459c2cSDavid du Colombier 	o++;
49*0b459c2cSDavid du Colombier       if (!*o)
50*0b459c2cSDavid du Colombier 	return n;
51*0b459c2cSDavid du Colombier       if (argv)
52*0b459c2cSDavid du Colombier 	argv[n] = b;
53*0b459c2cSDavid du Colombier       n++;
54*0b459c2cSDavid du Colombier 
55*0b459c2cSDavid du Colombier       do
56*0b459c2cSDavid du Colombier 	if ((*b++ = *o++) == '\\' && *o)
57*0b459c2cSDavid du Colombier 	  b[-1] = *o++;
58*0b459c2cSDavid du Colombier       while (*o && ! ISSPACE ((unsigned char) *o));
59*0b459c2cSDavid du Colombier 
60*0b459c2cSDavid du Colombier       *b++ = '\0';
61*0b459c2cSDavid du Colombier     }
62*0b459c2cSDavid du Colombier }
63*0b459c2cSDavid du Colombier 
64*0b459c2cSDavid du Colombier /* Prepend the whitespace-separated options in OPTIONS to the argument
65*0b459c2cSDavid du Colombier    vector of a main program with argument count *PARGC and argument
66*0b459c2cSDavid du Colombier    vector *PARGV.  */
67*0b459c2cSDavid du Colombier void
prepend_default_options(options,pargc,pargv)68*0b459c2cSDavid du Colombier prepend_default_options (options, pargc, pargv)
69*0b459c2cSDavid du Colombier      char const *options;
70*0b459c2cSDavid du Colombier      int *pargc;
71*0b459c2cSDavid du Colombier      char ***pargv;
72*0b459c2cSDavid du Colombier {
73*0b459c2cSDavid du Colombier   if (options)
74*0b459c2cSDavid du Colombier     {
75*0b459c2cSDavid du Colombier       char *buf = xmalloc (strlen (options) + 1);
76*0b459c2cSDavid du Colombier       int prepended = prepend_args (options, buf, (char **) NULL);
77*0b459c2cSDavid du Colombier       int argc = *pargc;
78*0b459c2cSDavid du Colombier       char * const *argv = *pargv;
79*0b459c2cSDavid du Colombier       char **pp = (char **) xmalloc ((prepended + argc + 1) * sizeof *pp);
80*0b459c2cSDavid du Colombier       *pargc = prepended + argc;
81*0b459c2cSDavid du Colombier       *pargv = pp;
82*0b459c2cSDavid du Colombier       *pp++ = *argv++;
83*0b459c2cSDavid du Colombier       pp += prepend_args (options, buf, pp);
84*0b459c2cSDavid du Colombier       while ((*pp++ = *argv++))
85*0b459c2cSDavid du Colombier 	continue;
86*0b459c2cSDavid du Colombier     }
87*0b459c2cSDavid du Colombier }
88