empserver/src/lib/gen/fnameat.c
Markus Armbruster b76e5a5eed Make conftab.c independent of the current directory
read_builtin_tables() wanted to run in builtindir, and
read_custom_tables() wanted to run in configdir.  Bothersome.  Use new
fopenat() to relax those requirements.

The chdir() satisfying them are now superflous, remove them.
2008-02-07 08:01:54 +01:00

96 lines
2.5 KiB
C

/*
* Empire - A multi-player, client/server Internet based war game.
* Copyright (C) 1986-2008, Dave Pare, Jeff Bailey, Thomas Ruschak,
* Ken Stevens, Steve McClure
*
* 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 of the License, 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
*
* ---
*
* See files README, COPYING and CREDITS in the root of the source
* tree for related information and legal notices. It is expected
* that future projects/authors will amend these files as needed.
*
* ---
*
* fnameat.c: Interpret file names relative to a directory
*
* Known contributors to this file:
* Markus Armbruster, 2008
*/
#include <config.h>
#include <errno.h>
#include "prototypes.h"
static int fname_is_abs(const char *);
/*
* Interpret FNAME relative to directory DIR.
* Return FNAME if it is absolute, or DIR is null or empty.
* Else return a malloc'ed string containing DIR/FNAME, or null
* pointer when that fails.
*/
char *
fnameat(const char *fname, const char *dir)
{
char *res;
if (fname_is_abs(fname) || !dir || !*dir)
return (char *)fname;
res = malloc(strlen(dir) + 1 + strlen(fname) + 1);
if (!res)
return NULL;
sprintf(res, "%s/%s", dir, fname);
return res;
}
static int
fname_is_abs(const char *fname)
{
#ifdef _WIN32
/* Treat as absolute if it starts with '/', '\\' or a drive */
return fname[0] == '/' || fname[0] == '\\'
|| (fname[0] != 0 && fname[1] == ':');
#else
return fname[0] == '/';
#endif
}
/*
* Open a stream like fopen(), optionally relative to a directory.
* This is exactly like fopen(), except FNAME is interpreted relative
* to DIR if that is neither null nor empty.
*/
FILE *
fopenat(const char *fname, const char *mode, const char *dir)
{
char *fnat;
FILE *fp;
fnat = fnameat(fname, dir);
if (!fnat)
return NULL;
fp = fopen(fnat, mode);
if (fnat != fname)
free(fnat);
return fp;
}