gen.subproj/getusershell.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1985, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * Redistribution and use in source and binary forms, with or without
  27  * modification, are permitted provided that the following conditions
  28  * are met:
  29  * 1. Redistributions of source code must retain the above copyright
  30  *    notice, this list of conditions and the following disclaimer.
  31  * 2. Redistributions in binary form must reproduce the above copyright
  32  *    notice, this list of conditions and the following disclaimer in the
  33  *    documentation and/or other materials provided with the distribution.
  34  * 3. All advertising materials mentioning features or use of this software
  35  *    must display the following acknowledgement:
  36  *      This product includes software developed by the University of
  37  *      California, Berkeley and its contributors.
  38  * 4. Neither the name of the University nor the names of its contributors
  39  *    may be used to endorse or promote products derived from this software
  40  *    without specific prior written permission.
  41  *
  42  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  52  * SUCH DAMAGE.
  53  */
  54
  55
  56 #include <sys/param.h>
  57 #include <sys/file.h>
  58 #include <sys/stat.h>
  59 #include <stdio.h>
  60 #include <ctype.h>
  61 #include <stdlib.h>
  62 #include <unistd.h>
  63 #include <paths.h>
  64
  65 /*
  66  * Local shells should NOT be added here.  They should be added in
  67  * /etc/shells.
  68  */
  69
  70 static char *okshells[] = { _PATH_BSHELL, _PATH_CSHELL, NULL };
  71 static char **curshell, **shells, *strings;
  72 static char **initshells __P((void));
  73
  74 /*
  75  * Get a list of shells from _PATH_SHELLS, if it exists.
  76  */
  77 char *
  78 getusershell()
  79 {
  80         char *ret;
  81
  82         if (curshell == NULL)
  83                 curshell = initshells();
  84         ret = *curshell;
  85         if (ret != NULL)
  86                 curshell++;
  87         return (ret);
  88 }
  89
  90 void
  91 endusershell()
  92 {
  93
  94         if (shells != NULL)
  95                 free(shells);
  96         shells = NULL;
  97         if (strings != NULL)
  98                 free(strings);
  99         strings = NULL;
 100         curshell = NULL;
 101 }
 102
 103 void
 104 setusershell()
 105 {
 106
 107         curshell = initshells();
 108 }
 109
 110 static char **
 111 initshells()
 112 {
 113         register char **sp, *cp;
 114         register FILE *fp;
 115         struct stat statb;
 116
 117         if (shells != NULL)
 118                 free(shells);
 119         shells = NULL;
 120         if (strings != NULL)
 121                 free(strings);
 122         strings = NULL;
 123         if ((fp = fopen(_PATH_SHELLS, "r")) == NULL)
 124                 return (okshells);
 125         if (fstat(fileno(fp), &statb) == -1) {
 126                 (void)fclose(fp);
 127                 return (okshells);
 128         }
 129         if ((strings = malloc((u_int)statb.st_size)) == NULL) {
 130                 (void)fclose(fp);
 131                 return (okshells);
 132         }
 133         shells = calloc((unsigned)statb.st_size / 3, sizeof (char *));
 134         if (shells == NULL) {
 135                 (void)fclose(fp);
 136                 free(strings);
 137                 strings = NULL;
 138                 return (okshells);
 139         }
 140         sp = shells;
 141         cp = strings;
 142         while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) {
 143                 while (*cp != '#' && *cp != '/' && *cp != '\0')
 144                         cp++;
 145                 if (*cp == '#' || *cp == '\0')
 146                         continue;
 147                 *sp++ = cp;
 148                 while (!isspace(*cp) && *cp != '#' && *cp != '\0')
 149                         cp++;
 150                 *cp++ = '\0';
 151         }
 152         *sp = NULL;
 153         (void)fclose(fp);
 154         return (shells);
 155 }