BSD 4_4 release

[unix-history] / usr / src / lib / libc / gen / confstr.c

/*-
* Copyright (c) 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.
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)confstr.c   8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */

#include <sys/param.h>
#include <sys/sysctl.h>

#include <errno.h>
#include <paths.h>
#include <stdlib.h>
#include <unistd.h>

size_t
confstr(name, buf, len)
       int name;
       char *buf;
       size_t len;
{
       size_t tlen;
       int mib[2], sverrno;
       char *p;

       switch (name) {
       case _CS_PATH:
               mib[0] = CTL_USER;
               mib[1] = USER_CS_PATH;
               if (sysctl(mib, 2, NULL, &tlen, NULL, 0) == -1)
                       return (-1);
               if (len != 0 && buf != NULL) {
                       if ((p = malloc(tlen)) == NULL)
                               return (-1);
                       if (sysctl(mib, 2, p, &tlen, NULL, 0) == -1) {
                               sverrno = errno;
                               free(p);
                               errno = sverrno;
                               return (-1);
                       }
                       /*
                        * POSIX 1003.2 requires partial return of
                        * the string -- that should be *real* useful.
                        */
                       (void)strncpy(buf, p, len - 1);
                       buf[len - 1] = '\0';
                       free(p);
               }
               return (tlen + 1);
       default:
               errno = EINVAL;
               return (0);
       }
       /* NOTREACHED */
}