4.3BSD - /usr/src/new/news/src/logdir.c

   1: /*
   2:  *	UNIX shell - logdir routine
   3:  *
   4:  *	Joe Steffen
   5:  *	Bell Telephone Laboratories
   6:  *
   7:  *	This routine does not use the getpwent(3) library routine
   8:  *	because the latter uses the stdio package.  The allocation of
   9:  *	storage in this package destroys the integrity of the shell's
  10:  *	storage allocation.
  11:  *
  12:  *	Modified 2/82 by DJ Molny
  13:  *
  14:  *	This routine now implements name cacheing, so multiple requests
  15:  *	for the same logdir do not result in multiple open/reads of
  16:  *	/etc/passwd.  If the previous request was successful and the name
  17:  *	is the same as the last request, the same login directory is returned.
  18:  */
  19: #ifdef SCCSID
  20: static char *SccsId = "@(#)logdir.c	1.4	4/16/85";
  21: #endif /* SCCSID */
  22: 
  23: #define BUFSIZ  160
  24: 
  25: static char line[BUFSIZ+1];
  26: 
  27: char *
  28: logdir(name)
  29: char *name;
  30: {
  31:     int pwf;
  32:     static char lastname[BUFSIZ+1];
  33:     static char lastdir[BUFSIZ+1];
  34:     register char *p;
  35:     register int i, j;
  36:     char *getenv(), *field(), *strcpy();
  37: 
  38:     if (*lastdir && !strcmp(lastname,name))     /* djm */
  39:         return(lastdir);
  40: 
  41:     strcpy(lastname, name);         /* djm */
  42:     strcpy(lastdir, "");            /* djm */
  43: 
  44: #ifdef IHCC
  45:     /* if the logname is exptools, see if $TOOLS is set */
  46:     if (strcmp(name, "exptools") &&
  47:         (p = getenv("TOOLS")) != 0 && *p != '\0') {
  48:         strcpy(lastdir, p);
  49:         return(lastdir);
  50:     }
  51: #endif
  52: 
  53:     /* attempt to open the password file */
  54:     if ((pwf = open("/etc/passwd", 0)) == -1)
  55:         return(0);
  56: 
  57:     /* find the matching password entry */
  58:     do {
  59:         /* get the next line in the password file */
  60:         i = read(pwf, line, BUFSIZ);
  61:         for (j = 0; j < i; j++)
  62:             if (line[j] == '\n')
  63:                 break;
  64:         /* return a null pointer if the whole file has been read */
  65:         if (j >= i)
  66:             return(0);
  67:         line[++j] = 0;          /* terminate the line */
  68:         lseek(pwf, (long) (j - i), 1);  /* point at the next line */
  69:         p = field(line);        /* get the logname */
  70:     } while (strcmp(name, line) != 0);
  71:     close(pwf);
  72: 
  73:     /* skip the intervening fields */
  74:     p = field(p);
  75:     p = field(p);
  76:     p = field(p);
  77:     p = field(p);
  78: 
  79:     /* return the login directory */
  80:     field(p);
  81:     strcpy(lastdir,p);          /* djm */
  82:     return(p);
  83: }
  84: 
  85: static char *
  86: field(p)
  87: register char *p;
  88: {
  89:     while (*p && *p != ':')
  90:         ++p;
  91:     if (*p) *p++ = 0;
  92:     return(p);
  93: }

Defined functions

Defined variables

Defined macros