4.3BSD - /usr/src/lib/libc/gen/getusershell.c

   1: /*
   2:  * Copyright (c) 1985 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #if defined(LIBC_SCCS) && !defined(lint)
   8: static char sccsid[] = "@(#)getusershell.c	5.2 (Berkeley) 3/9/86";
   9: #endif LIBC_SCCS and not lint
  10: 
  11: #include <sys/param.h>
  12: #include <sys/file.h>
  13: #include <sys/stat.h>
  14: #include <ctype.h>
  15: #include <stdio.h>
  16: 
  17: #define SHELLS "/etc/shells"
  18: 
  19: /*
  20:  * Do not add local shells here.  They should be added in /etc/shells
  21:  */
  22: static char *okshells[] =
  23:     { "/bin/sh", "/bin/csh", 0 };
  24: 
  25: static int inprogress;
  26: static char **shells, *strings;
  27: extern char **initshells();
  28: 
  29: /*
  30:  * Get a list of shells from SHELLS, if it exists.
  31:  */
  32: char *
  33: getusershell()
  34: {
  35:     char *ret;
  36:     static char **shells;
  37: 
  38:     if (!inprogress)
  39:         shells = initshells();
  40:     ret = *shells;
  41:     if (*shells != NULL)
  42:         shells++;
  43:     return (ret);
  44: }
  45: 
  46: endusershell()
  47: {
  48: 
  49:     if (shells != NULL)
  50:         free((char *)shells);
  51:     shells = NULL;
  52:     if (strings != NULL)
  53:         free(strings);
  54:     strings = NULL;
  55:     inprogress = 0;
  56: }
  57: 
  58: setusershell()
  59: {
  60: 
  61:     shells = initshells();
  62: }
  63: 
  64: static char **
  65: initshells()
  66: {
  67:     register char **sp, *cp;
  68:     register FILE *fp;
  69:     struct stat statb;
  70:     extern char *malloc(), *calloc();
  71: 
  72:     inprogress = 1;
  73:     if (shells != NULL)
  74:         free((char *)shells);
  75:     shells = NULL;
  76:     if (strings != NULL)
  77:         free(strings);
  78:     strings = NULL;
  79:     if ((fp = fopen(SHELLS, "r")) == (FILE *)0)
  80:         return(okshells);
  81:     if (fstat(fileno(fp), &statb) == -1) {
  82:         (void)fclose(fp);
  83:         return(okshells);
  84:     }
  85:     if ((strings = malloc((unsigned)statb.st_size)) == NULL) {
  86:         (void)fclose(fp);
  87:         return(okshells);
  88:     }
  89:     shells = (char **)calloc((unsigned)statb.st_size / 3, sizeof (char *));
  90:     if (shells == NULL) {
  91:         (void)fclose(fp);
  92:         free(strings);
  93:         strings = NULL;
  94:         return(okshells);
  95:     }
  96:     sp = shells;
  97:     cp = strings;
  98:     while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) {
  99:         while (*cp != '/' && *cp != '\0')
 100:             cp++;
 101:         if (*cp == '\0')
 102:             continue;
 103:         *sp++ = cp;
 104:         while (!isspace(*cp) && *cp != '#' && *cp != '\0')
 105:             cp++;
 106:         *cp++ = '\0';
 107:     }
 108:     *sp = (char *)0;
 109:     (void)fclose(fp);
 110:     return (shells);
 111: }

Defined functions

Defined variables

Defined macros