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freebsd/contrib/diff/prepend_args.c
David E. O'Brien 20ee132cae * Support the environtmental var "DIFF_OPTIONS". Which can hold a set of
default options for diff.  These options are interpreted first and can be
overwritten by explicit command line parameters.
* Add the "-o" option to specify old-traditional output style.
* Add utility functions for env vars obtained from GNU Grep 2.3h.
1999-11-26 02:51:44 +00:00

87 lines
2.4 KiB
C

/* prepend_args.c - utilility programs for manpiulating argv[]
Copyright (C) 1999 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. */
/* $FreeBSD$ */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "system.h"
#include "prepend_args.h"
/* 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] to NULL. If ARGV is NULL, do not store ARGV[0]
etc. Backslash can be used to escape whitespace (and backslashes). */
static int
prepend_args (options, buf, argv)
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 (options, pargc, pargv)
char const *options;
int *pargc;
char ***pargv;
{
if (options)
{
char *buf = xmalloc (strlen (options) + 1);
int prepended = prepend_args (options, buf, (char **) NULL);
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;
}
}