aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/curl/lib/getenv.c
blob: 0c84959bc85816483be7d98eb9370033ff6baa67 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al. 
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.se/docs/copyright.html. 
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

#include "curl_setup.h"

#include <curl/curl.h>
#include "curl_memory.h"

#include "memdebug.h"

static char *GetEnv(const char *variable) 
{
#if defined(_WIN32_WCE) || defined(CURL_WINDOWS_APP)
  (void)variable;
  return NULL;
#elif defined(WIN32) 
  /* This uses Windows API instead of C runtime getenv() to get the environment 
     variable since some changes aren't always visible to the latter. #4774 */ 
  char *buf = NULL; 
  char *tmp; 
  DWORD bufsize; 
  DWORD rc = 1; 
  const DWORD max = 32768; /* max env var size from MSCRT source */ 
 
  for(;;) { 
    tmp = realloc(buf, rc); 
    if(!tmp) { 
      free(buf); 
      return NULL; 
    } 
 
    buf = tmp; 
    bufsize = rc; 
 
    /* It's possible for rc to be 0 if the variable was found but empty. 
       Since getenv doesn't make that distinction we ignore it as well. */ 
    rc = GetEnvironmentVariableA(variable, buf, bufsize); 
    if(!rc || rc == bufsize || rc > max) { 
      free(buf); 
      return NULL; 
    } 
 
    /* if rc < bufsize then rc is bytes written not including null */ 
    if(rc < bufsize) 
      return buf; 
 
    /* else rc is bytes needed, try again */ 
  } 
#else
  char *env = getenv(variable);
  return (env && env[0])?strdup(env):NULL;
#endif
}

char *curl_getenv(const char *v)
{
  return GetEnv(v);
}