compiler/clib/getenv.c

   1 /*
   2     Copyright © 1995-2012, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     C99 function getenv().
   6 */
   7
   8 #include <proto/exec.h>
   9 #include <proto/dos.h>
  10
  11 #include "__env.h"
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16 #include <stdlib.h>
  17
  18         char *getenv (
  19
  20 /*  SYNOPSIS */
  21         const char *name)
  22
  23 /*  FUNCTION
  24         Get an environment variable.
  25
  26     INPUTS
  27         name - Name of the environment variable.
  28
  29     RESULT
  30         Pointer to the variable's value, or NULL on failure.
  31
  32     NOTES
  33         This function must not be used in a shared library.
  34
  35     EXAMPLE
  36
  37     BUGS
  38
  39     SEE ALSO
  40
  41     INTERNALS
  42         Based on libnix getenv
  43
  44 ******************************************************************************/
  45 {
  46     __env_item *var = NULL;
  47     char  c;
  48
  49     /*
  50       This will always return 0 if the var exists and EOF if it doesn't,
  51       then we'll be able to retrieve the var lenght with IoErr()
  52     */
  53     if (!GetVar((char *)name, &c, 1, GVF_BINARY_VAR))
  54     {
  55         LONG len = IoErr();
  56
  57         var = __env_getvar(name, len+1); /* size == len + null-byte. */
  58
  59         if (var)
  60         {
  61             /*This should not fail, unless someone stealt our variable*/
  62             /* FIXME: maybe this function should be atomic? */
  63             GetVar((char *)name, var->value, len+1, GVF_BINARY_VAR);
  64         }
  65     }
  66
  67     return (var?var->value:NULL);
  68 } /* getenv */
  69