gen/getusershell.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * Copyright (c) 1985, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions
  29  * are met:
  30  * 1. Redistributions of source code must retain the above copyright
  31  *    notice, this list of conditions and the following disclaimer.
  32  * 2. Redistributions in binary form must reproduce the above copyright
  33  *    notice, this list of conditions and the following disclaimer in the
  34  *    documentation and/or other materials provided with the distribution.
  35  * 3. All advertising materials mentioning features or use of this software
  36  *    must display the following acknowledgement:
  37  *      This product includes software developed by the University of
  38  *      California, Berkeley and its contributors.
  39  * 4. Neither the name of the University nor the names of its contributors
  40  *    may be used to endorse or promote products derived from this software
  41  *    without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  */
  55
  56 #include "xlocale_private.h"
  57
  58 #include <sys/param.h>
  59 #include <sys/file.h>
  60 #include <sys/stat.h>
  61 #include <stdio.h>
  62 #include <ctype.h>
  63 #include <stdlib.h>
  64 #include <unistd.h>
  65 #include <paths.h>
  66
  67 /*
  68  * Local shells should NOT be added here.  They should be added in
  69  * /etc/shells.
  70  */
  71
  72 static char *okshells[] = { _PATH_BSHELL, _PATH_CSHELL, NULL };
  73 static char **curshell, **shells, *strings;
  74 static char **initshells(void);
  75
  76 /*
  77  * Get a list of shells from _PATH_SHELLS, if it exists.
  78  */
  79 char *
  80 getusershell()
  81 {
  82         char *ret;
  83
  84         if (curshell == NULL)
  85                 curshell = initshells();
  86         ret = *curshell;
  87         if (ret != NULL)
  88                 curshell++;
  89         return (ret);
  90 }
  91
  92 void
  93 endusershell()
  94 {
  95
  96         if (shells != NULL)
  97                 free(shells);
  98         shells = NULL;
  99         if (strings != NULL)
 100                 free(strings);
 101         strings = NULL;
 102         curshell = NULL;
 103 }
 104
 105 void
 106 setusershell()
 107 {
 108
 109         curshell = initshells();
 110 }
 111
 112 static char **
 113 initshells()
 114 {
 115         register char **sp, *cp;
 116         register FILE *fp;
 117         struct stat statb;
 118         locale_t loc = __current_locale();
 119
 120         if (shells != NULL)
 121                 free(shells);
 122         shells = NULL;
 123         if (strings != NULL)
 124                 free(strings);
 125         strings = NULL;
 126         if ((fp = fopen(_PATH_SHELLS, "r")) == NULL)
 127                 return (okshells);
 128         if (fstat(fileno(fp), &statb) == -1) {
 129                 (void)fclose(fp);
 130                 return (okshells);
 131         }
 132         if ((strings = malloc((u_int)statb.st_size)) == NULL) {
 133                 (void)fclose(fp);
 134                 return (okshells);
 135         }
 136         shells = calloc((unsigned)statb.st_size / 3, sizeof (char *));
 137         if (shells == NULL) {
 138                 (void)fclose(fp);
 139                 free(strings);
 140                 strings = NULL;
 141                 return (okshells);
 142         }
 143         sp = shells;
 144         cp = strings;
 145         while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) {
 146                 while (*cp != '#' && *cp != '/' && *cp != '\0')
 147                         cp++;
 148                 if (*cp == '#' || *cp == '\0')
 149                         continue;
 150                 *sp++ = cp;
 151                 while (!isspace_l(*cp, loc) && *cp != '#' && *cp != '\0')
 152                         cp++;
 153                 *cp++ = '\0';
 154         }
 155         *sp = NULL;
 156         (void)fclose(fp);
 157         return (shells);
 158 }