freebsd-skq/contrib/diff/lib/prepargs.c
2007-06-15 07:06:13 +00:00

94 lines
2.7 KiB
C

/* Parse arguments from a string and prepend them to an argv.
Copyright (C) 1999, 2000, 2001, 2002 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. */
/* Written by Paul Eggert <eggert@twinsun.com>. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "prepargs.h"
#include <string.h>
#include <sys/types.h>
#include <xalloc.h>
#include <ctype.h>
/* IN_CTYPE_DOMAIN (C) is nonzero if the unsigned char C can safely be given
as an argument to <ctype.h> macros like "isspace". */
#ifdef STDC_HEADERS
# define IN_CTYPE_DOMAIN(c) 1
#else
# define IN_CTYPE_DOMAIN(c) ((c) <= 0177)
#endif
#define ISSPACE(c) (IN_CTYPE_DOMAIN (c) && isspace (c))
/* 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]. If ARGV is zero, do not store ARGV[0] etc.
Backslash can be used to escape whitespace (and backslashes). */
static int
prepend_args (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 (char const *options, int *pargc, char ***pargv)
{
if (options)
{
char *buf = xmalloc (strlen (options) + 1);
int prepended = prepend_args (options, buf, (char **) 0);
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;
}
}