NetBSD/lib/libc/gen/getusershell.c

154 lines
4.1 KiB
C

/* $NetBSD: getusershell.c,v 1.10 1998/07/27 09:47:45 mycroft Exp $ */
/*
* Copyright (c) 1985, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)getusershell.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: getusershell.c,v 1.10 1998/07/27 09:47:45 mycroft Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/param.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>
#include <paths.h>
#ifdef __weak_alias
__weak_alias(endusershell,_endusershell);
__weak_alias(getusershell,_getusershell);
__weak_alias(setusershell,_setusershell);
#endif
/*
* Local shells should NOT be added here. They should be added in
* /etc/shells.
*/
static const char *const okshells[] = { _PATH_BSHELL, _PATH_CSHELL, NULL };
static const char *const *curshell, **shells;
static char *strings;
static const char *const *initshells __P((void));
/*
* Get a list of shells from _PATH_SHELLS, if it exists.
*/
__aconst char *
getusershell()
{
__aconst char *ret;
if (curshell == NULL)
curshell = initshells();
ret = (__aconst char *)*curshell;
if (ret != NULL)
curshell++;
return (ret);
}
void
endusershell()
{
if (shells != NULL)
free(shells);
shells = NULL;
if (strings != NULL)
free(strings);
strings = NULL;
curshell = NULL;
}
void
setusershell()
{
curshell = initshells();
}
static const char *const *
initshells()
{
const char **sp;
char *cp;
FILE *fp;
struct stat statb;
if (shells != NULL)
free(shells);
shells = NULL;
if (strings != NULL)
free(strings);
strings = NULL;
if ((fp = fopen(_PATH_SHELLS, "r")) == NULL)
return (okshells);
if (fstat(fileno(fp), &statb) == -1) {
(void)fclose(fp);
return (okshells);
}
if ((cp = malloc((u_int)statb.st_size)) == NULL) {
(void)fclose(fp);
return (okshells);
}
sp = calloc((unsigned)statb.st_size / 3, sizeof (char *));
if (sp == NULL) {
(void)fclose(fp);
free(cp);
strings = NULL;
return (okshells);
}
shells = sp;
strings = cp;
while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) {
while (*cp != '#' && *cp != '/' && *cp != '\0')
cp++;
if (*cp == '#' || *cp == '\0')
continue;
*sp++ = cp;
while (!isspace(*cp) && *cp != '#' && *cp != '\0')
cp++;
*cp++ = '\0';
}
*sp = NULL;
(void)fclose(fp);
return (shells);
}