lib/ansi/getenv.c

   1 /*
   2  * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
   3  * See the copyright notice in the ACK home directory, in the file "Copyright".
   4  */
   5 /* $Header$ */
   6
   7 #include        <stdlib.h>
   8
   9 extern const char ***_penviron;
  10
  11 char *
  12 getenv(const char *name)
  13 {
  14         register const char **v = *_penviron;
  15         register const char *p, *q;
  16
  17         if (v == NULL || name == NULL)
  18                 return (char *)NULL;
  19         while ((p = *v++) != NULL) {
  20                 q = name;
  21                 while (*q && (*q == *p++))
  22                         q++;
  23                 if (*q || (*p != '='))
  24                         continue;
  25                 return (char *)p + 1;
  26         }
  27         return (char *)NULL;
  28 }