SDL  2.0
SDL_getenv.c
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 
22 #if defined(__clang_analyzer__) && !defined(SDL_DISABLE_ANALYZE_MACROS)
23 #define SDL_DISABLE_ANALYZE_MACROS 1
24 #endif
25 
26 #include "../SDL_internal.h"
27 
28 #if defined(__WIN32__)
29 #include "../core/windows/SDL_windows.h"
30 #endif
31 
32 #include "SDL_stdinc.h"
33 
34 #if defined(__WIN32__) && (!defined(HAVE_SETENV) || !defined(HAVE_GETENV))
35 /* Note this isn't thread-safe! */
36 static char *SDL_envmem = NULL; /* Ugh, memory leak */
37 static size_t SDL_envmemlen = 0;
38 #endif
39 
40 /* Put a variable into the environment */
41 /* Note: Name may not contain a '=' character. (Reference: http://www.unix.com/man-page/Linux/3/setenv/) */
42 #if defined(HAVE_SETENV)
43 int
44 SDL_setenv(const char *name, const char *value, int overwrite)
45 {
46  /* Input validation */
47  if (!name || SDL_strlen(name) == 0 || SDL_strchr(name, '=') != NULL || !value) {
48  return (-1);
49  }
50 
51  return setenv(name, value, overwrite);
52 }
53 #elif defined(__WIN32__)
54 int
55 SDL_setenv(const char *name, const char *value, int overwrite)
56 {
57  /* Input validation */
58  if (!name || SDL_strlen(name) == 0 || SDL_strchr(name, '=') != NULL || !value) {
59  return (-1);
60  }
61 
62  if (!overwrite) {
63  char ch = 0;
64  const size_t len = GetEnvironmentVariableA(name, &ch, sizeof (ch));
65  if (len > 0) {
66  return 0; /* asked not to overwrite existing value. */
67  }
68  }
69  if (!SetEnvironmentVariableA(name, *value ? value : NULL)) {
70  return -1;
71  }
72  return 0;
73 }
74 /* We have a real environment table, but no real setenv? Fake it w/ putenv. */
75 #elif (defined(HAVE_GETENV) && defined(HAVE_PUTENV) && !defined(HAVE_SETENV))
76 int
77 SDL_setenv(const char *name, const char *value, int overwrite)
78 {
79  size_t len;
80  char *new_variable;
81 
82  /* Input validation */
83  if (!name || SDL_strlen(name) == 0 || SDL_strchr(name, '=') != NULL || !value) {
84  return (-1);
85  }
86 
87  if (getenv(name) != NULL) {
88  if (overwrite) {
89  unsetenv(name);
90  } else {
91  return 0; /* leave the existing one there. */
92  }
93  }
94 
95  /* This leaks. Sorry. Get a better OS so we don't have to do this. */
96  len = SDL_strlen(name) + SDL_strlen(value) + 2;
97  new_variable = (char *) SDL_malloc(len);
98  if (!new_variable) {
99  return (-1);
100  }
101 
102  SDL_snprintf(new_variable, len, "%s=%s", name, value);
103  return putenv(new_variable);
104 }
105 #else /* roll our own */
106 static char **SDL_env = (char **) 0;
107 int
108 SDL_setenv(const char *name, const char *value, int overwrite)
109 {
110  int added;
111  int len, i;
112  char **new_env;
113  char *new_variable;
114 
115  /* Input validation */
116  if (!name || SDL_strlen(name) == 0 || SDL_strchr(name, '=') != NULL || !value) {
117  return (-1);
118  }
119 
120  /* See if it already exists */
121  if (!overwrite && SDL_getenv(name)) {
122  return 0;
123  }
124 
125  /* Allocate memory for the variable */
126  len = SDL_strlen(name) + SDL_strlen(value) + 2;
127  new_variable = (char *) SDL_malloc(len);
128  if (!new_variable) {
129  return (-1);
130  }
131 
132  SDL_snprintf(new_variable, len, "%s=%s", name, value);
133  value = new_variable + SDL_strlen(name) + 1;
134  name = new_variable;
135 
136  /* Actually put it into the environment */
137  added = 0;
138  i = 0;
139  if (SDL_env) {
140  /* Check to see if it's already there... */
141  len = (value - name);
142  for (; SDL_env[i]; ++i) {
143  if (SDL_strncmp(SDL_env[i], name, len) == 0) {
144  break;
145  }
146  }
147  /* If we found it, just replace the entry */
148  if (SDL_env[i]) {
149  SDL_free(SDL_env[i]);
150  SDL_env[i] = new_variable;
151  added = 1;
152  }
153  }
154 
155  /* Didn't find it in the environment, expand and add */
156  if (!added) {
157  new_env = SDL_realloc(SDL_env, (i + 2) * sizeof(char *));
158  if (new_env) {
159  SDL_env = new_env;
160  SDL_env[i++] = new_variable;
161  SDL_env[i++] = (char *) 0;
162  added = 1;
163  } else {
164  SDL_free(new_variable);
165  }
166  }
167  return (added ? 0 : -1);
168 }
169 #endif
170 
171 /* Retrieve a variable named "name" from the environment */
172 #if defined(HAVE_GETENV)
173 char *
174 SDL_getenv(const char *name)
175 {
176  /* Input validation */
177  if (!name || SDL_strlen(name)==0) {
178  return NULL;
179  }
180 
181  return getenv(name);
182 }
183 #elif defined(__WIN32__)
184 char *
185 SDL_getenv(const char *name)
186 {
187  size_t bufferlen;
188 
189  /* Input validation */
190  if (!name || SDL_strlen(name)==0) {
191  return NULL;
192  }
193 
194  bufferlen =
195  GetEnvironmentVariableA(name, SDL_envmem, (DWORD) SDL_envmemlen);
196  if (bufferlen == 0) {
197  return NULL;
198  }
199  if (bufferlen > SDL_envmemlen) {
200  char *newmem = (char *) SDL_realloc(SDL_envmem, bufferlen);
201  if (newmem == NULL) {
202  return NULL;
203  }
204  SDL_envmem = newmem;
205  SDL_envmemlen = bufferlen;
206  GetEnvironmentVariableA(name, SDL_envmem, (DWORD) SDL_envmemlen);
207  }
208  return SDL_envmem;
209 }
210 #else
211 char *
212 SDL_getenv(const char *name)
213 {
214  int len, i;
215  char *value;
216 
217  /* Input validation */
218  if (!name || SDL_strlen(name)==0) {
219  return NULL;
220  }
221 
222  value = (char *) 0;
223  if (SDL_env) {
224  len = SDL_strlen(name);
225  for (i = 0; SDL_env[i] && !value; ++i) {
226  if ((SDL_strncmp(SDL_env[i], name, len) == 0) &&
227  (SDL_env[i][len] == '=')) {
228  value = &SDL_env[i][len + 1];
229  }
230  }
231  }
232  return value;
233 }
234 #endif
235 
236 
237 #ifdef TEST_MAIN
238 #include <stdio.h>
239 
240 int
241 main(int argc, char *argv[])
242 {
243  char *value;
244 
245  printf("Checking for non-existent variable... ");
246  fflush(stdout);
247  if (!SDL_getenv("EXISTS")) {
248  printf("okay\n");
249  } else {
250  printf("failed\n");
251  }
252  printf("Setting FIRST=VALUE1 in the environment... ");
253  fflush(stdout);
254  if (SDL_setenv("FIRST", "VALUE1", 0) == 0) {
255  printf("okay\n");
256  } else {
257  printf("failed\n");
258  }
259  printf("Getting FIRST from the environment... ");
260  fflush(stdout);
261  value = SDL_getenv("FIRST");
262  if (value && (SDL_strcmp(value, "VALUE1") == 0)) {
263  printf("okay\n");
264  } else {
265  printf("failed\n");
266  }
267  printf("Setting SECOND=VALUE2 in the environment... ");
268  fflush(stdout);
269  if (SDL_setenv("SECOND", "VALUE2", 0) == 0) {
270  printf("okay\n");
271  } else {
272  printf("failed\n");
273  }
274  printf("Getting SECOND from the environment... ");
275  fflush(stdout);
276  value = SDL_getenv("SECOND");
277  if (value && (SDL_strcmp(value, "VALUE2") == 0)) {
278  printf("okay\n");
279  } else {
280  printf("failed\n");
281  }
282  printf("Setting FIRST=NOVALUE in the environment... ");
283  fflush(stdout);
284  if (SDL_setenv("FIRST", "NOVALUE", 1) == 0) {
285  printf("okay\n");
286  } else {
287  printf("failed\n");
288  }
289  printf("Getting FIRST from the environment... ");
290  fflush(stdout);
291  value = SDL_getenv("FIRST");
292  if (value && (SDL_strcmp(value, "NOVALUE") == 0)) {
293  printf("okay\n");
294  } else {
295  printf("failed\n");
296  }
297  printf("Checking for non-existent variable... ");
298  fflush(stdout);
299  if (!SDL_getenv("EXISTS")) {
300  printf("okay\n");
301  } else {
302  printf("failed\n");
303  }
304  return (0);
305 }
306 #endif /* TEST_MAIN */
307 
308 /* vi: set ts=4 sw=4 expandtab: */
char * SDL_getenv(const char *name)
Definition: SDL_getenv.c:212
GLuint const GLchar * name
#define SDL_realloc
#define SDL_strncmp
static char ** SDL_env
Definition: SDL_getenv.c:106
GLenum GLsizei len
#define SDL_strchr
GLsizei const GLfloat * value
void SDL_free(void *mem)
int SDL_setenv(const char *name, const char *value, int overwrite)
Definition: SDL_getenv.c:108
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
Definition: SDL_x11sym.h:42
#define NULL
Definition: begin_code.h:143
#define SDL_strlen
#define SDL_snprintf
#define SDL_malloc
#define main
Definition: SDL_main.h:104
#define SDL_strcmp