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Annotation of embedaddon/curl/lib/getenv.c, revision 1.1.1.1

1.1       misho       1: /***************************************************************************
                      2:  *                                  _   _ ____  _
                      3:  *  Project                     ___| | | |  _ \| |
                      4:  *                             / __| | | | |_) | |
                      5:  *                            | (__| |_| |  _ <| |___
                      6:  *                             \___|\___/|_| \_\_____|
                      7:  *
                      8:  * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
                      9:  *
                     10:  * This software is licensed as described in the file COPYING, which
                     11:  * you should have received as part of this distribution. The terms
                     12:  * are also available at https://curl.haxx.se/docs/copyright.html.
                     13:  *
                     14:  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
                     15:  * copies of the Software, and permit persons to whom the Software is
                     16:  * furnished to do so, under the terms of the COPYING file.
                     17:  *
                     18:  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
                     19:  * KIND, either express or implied.
                     20:  *
                     21:  ***************************************************************************/
                     22: 
                     23: #include "curl_setup.h"
                     24: 
                     25: #include <curl/curl.h>
                     26: #include "curl_memory.h"
                     27: 
                     28: #include "memdebug.h"
                     29: 
                     30: static char *GetEnv(const char *variable)
                     31: {
                     32: #if defined(_WIN32_WCE) || defined(CURL_WINDOWS_APP)
                     33:   (void)variable;
                     34:   return NULL;
                     35: #elif defined(WIN32)
                     36:   /* This uses Windows API instead of C runtime getenv() to get the environment
                     37:      variable since some changes aren't always visible to the latter. #4774 */
                     38:   char *buf = NULL;
                     39:   char *tmp;
                     40:   DWORD bufsize;
                     41:   DWORD rc = 1;
                     42:   const DWORD max = 32768; /* max env var size from MSCRT source */
                     43: 
                     44:   for(;;) {
                     45:     tmp = realloc(buf, rc);
                     46:     if(!tmp) {
                     47:       free(buf);
                     48:       return NULL;
                     49:     }
                     50: 
                     51:     buf = tmp;
                     52:     bufsize = rc;
                     53: 
                     54:     /* It's possible for rc to be 0 if the variable was found but empty.
                     55:        Since getenv doesn't make that distinction we ignore it as well. */
                     56:     rc = GetEnvironmentVariableA(variable, buf, bufsize);
                     57:     if(!rc || rc == bufsize || rc > max) {
                     58:       free(buf);
                     59:       return NULL;
                     60:     }
                     61: 
                     62:     /* if rc < bufsize then rc is bytes written not including null */
                     63:     if(rc < bufsize)
                     64:       return buf;
                     65: 
                     66:     /* else rc is bytes needed, try again */
                     67:   }
                     68: #else
                     69:   char *env = getenv(variable);
                     70:   return (env && env[0])?strdup(env):NULL;
                     71: #endif
                     72: }
                     73: 
                     74: char *curl_getenv(const char *v)
                     75: {
                     76:   return GetEnv(v);
                     77: }