2.11BSD#431 - /usr/src/lib/libc/gen/getusershell.c

   1: /*
   2:  * Copyright (c) 1985 Regents of the University of California.
   3:  * All rights reserved.
   4:  *
   5:  * Redistribution and use in source and binary forms are permitted
   6:  * provided that the above copyright notice and this paragraph are
   7:  * duplicated in all such forms and that any documentation,
   8:  * advertising materials, and other materials related to such
   9:  * distribution and use acknowledge that the software was developed
  10:  * by the University of California, Berkeley.  The name of the
  11:  * University may not be used to endorse or promote products derived
  12:  * from this software without specific prior written permission.
  13:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  14:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  15:  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  16:  */
  17: 
  18: #if defined(LIBC_SCCS) && !defined(lint)
  19: static char sccsid[] = "@(#)getusershell.c	5.5 (Berkeley) 7/21/88";
  20: #endif /* LIBC_SCCS and not lint */
  21: 
  22: #include <sys/param.h>
  23: #include <sys/file.h>
  24: #include <sys/stat.h>
  25: #include <ctype.h>
  26: #include <stdio.h>
  27: 
  28: #define SHELLS "/etc/shells"
  29: 
  30: /*
  31:  * Do not add local shells here.  They should be added in /etc/shells
  32:  */
  33: static char *okshells[] =
  34:     { "/bin/sh", "/bin/csh", 0 };
  35: 
  36: static char **shells, *strings;
  37: static char **curshell = NULL;
  38: extern char **initshells();
  39: 
  40: /*
  41:  * Get a list of shells from SHELLS, if it exists.
  42:  */
  43: char *
  44: getusershell()
  45: {
  46:     char *ret;
  47: 
  48:     if (curshell == NULL)
  49:         curshell = initshells();
  50:     ret = *curshell;
  51:     if (ret != NULL)
  52:         curshell++;
  53:     return (ret);
  54: }
  55: 
  56: endusershell()
  57: {
  58: 
  59:     if (shells != NULL)
  60:         free((char *)shells);
  61:     shells = NULL;
  62:     if (strings != NULL)
  63:         free(strings);
  64:     strings = NULL;
  65:     curshell = NULL;
  66: }
  67: 
  68: setusershell()
  69: {
  70: 
  71:     curshell = initshells();
  72: }
  73: 
  74: static char **
  75: initshells()
  76: {
  77:     register char **sp, *cp;
  78:     register FILE *fp;
  79:     struct stat statb;
  80:     extern char *malloc(), *calloc();
  81: 
  82:     if (shells != NULL)
  83:         free((char *)shells);
  84:     shells = NULL;
  85:     if (strings != NULL)
  86:         free(strings);
  87:     strings = NULL;
  88:     if ((fp = fopen(SHELLS, "r")) == (FILE *)0)
  89:         return(okshells);
  90:     if (fstat(fileno(fp), &statb) == -1) {
  91:         (void)fclose(fp);
  92:         return(okshells);
  93:     }
  94:     if ((strings = malloc((unsigned)statb.st_size)) == NULL) {
  95:         (void)fclose(fp);
  96:         return(okshells);
  97:     }
  98:     shells = (char **)calloc((unsigned)statb.st_size / 3, sizeof (char *));
  99:     if (shells == NULL) {
 100:         (void)fclose(fp);
 101:         free(strings);
 102:         strings = NULL;
 103:         return(okshells);
 104:     }
 105:     sp = shells;
 106:     cp = strings;
 107:     while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) {
 108:         while (*cp != '#' && *cp != '/' && *cp != '\0')
 109:             cp++;
 110:         if (*cp == '#' || *cp == '\0')
 111:             continue;
 112:         *sp++ = cp;
 113:         while (!isspace(*cp) && *cp != '#' && *cp != '\0')
 114:             cp++;
 115:         *cp++ = '\0';
 116:     }
 117:     *sp = (char *)0;
 118:     (void)fclose(fp);
 119:     return (shells);
 120: }

Defined functions

Defined variables

Defined macros