src/util/env.c

   1 /** Environment variables handling
   2  * @file */
   3
   4 #ifdef HAVE_CONFIG_H
   5 #include "config.h"
   6 #endif
   7
   8 #include <ctype.h>
   9 #include <errno.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13
  14 #include "elinks.h"
  15
  16 #include "util/env.h"
  17 #include "util/memory.h"
  18 #include "util/string.h"
  19
  20 /** Set @a name environment variable to @a value or a substring of it:
  21  * On success, it returns 0.
  22  * If @a value is NULL and on error, it returns -1.
  23  * If @a length >= 0 and smaller than true @a value length, it will
  24  * set @a name to specified substring of @a value.
  25  */
  26 int
  27 env_set(unsigned char *name, unsigned char *value, int length)
  28 {
  29         int true_length, substring = 0;
  30
  31         if (!value || !name || !*name) return -1;
  32
  33         true_length = strlen(value);
  34         substring = (length >= 0 && length < true_length);
  35         if (!substring) length = true_length;
  36
  37 #if defined(HAVE_SETENV)
  38         {
  39                 int ret, allocated = 0;
  40
  41                 if (substring) {
  42                         /* Copy the substring. */
  43                         value = memacpy(value, length);
  44                         if (!value) return -1;
  45                         allocated = 1;
  46                 }
  47
  48                 ret = setenv(name, value, 1);
  49                 if (allocated) mem_free(value);
  50                 return ret;
  51         }
  52
  53 #elif defined(HAVE_PUTENV)
  54
  55         {
  56                 int namelen = strlen(name);
  57                 char *s = malloc(namelen + length + 2);
  58
  59                 if (!s) return -1;
  60                 memcpy(s, name, namelen);
  61                 s[namelen] = '=';
  62                 memcpy(&s[namelen + 1], value, length);
  63                 s[namelen + 1 + length] = '\0';
  64
  65                 /* @s is never freed by us, this is intentional.
  66                  * --> Possible memleaks on repeated use of
  67                  * this function. */
  68                 return putenv(s);
  69         }
  70
  71 #else
  72         /* XXX: what to do ?? */
  73         return -1;
  74 #endif
  75 }