Atlas - SDL_getenv.c
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[FILE BEGIN]
1/*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2018 Sam Lantinga <[email protected]>
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#if defined(__ANDROID__)
33#include "../core/android/SDL_android.h"
34#endif
35
36#include "SDL_stdinc.h"
37
38#if defined(__WIN32__) && (!defined(HAVE_SETENV) || !defined(HAVE_GETENV))
39/* Note this isn't thread-safe! */
40static char *SDL_envmem = NULL; /* Ugh, memory leak */
41static size_t SDL_envmemlen = 0;
42#endif
43
44/* Put a variable into the environment */
45/* Note: Name may not contain a '=' character. (Reference: http://www.unix.com/man-page/Linux/3/setenv/) */
46#if defined(HAVE_SETENV)
47int
48SDL_setenv(const char *name, const char *value, int overwrite)
49{
50    /* Input validation */
51    if (!name || SDL_strlen(name) == 0 || SDL_strchr(name, '=') != NULL || !value) {
52        return (-1);
53    }
54    
55    return setenv(name, value, overwrite);
56}
57#elif defined(__WIN32__)
58int
59SDL_setenv(const char *name, const char *value, int overwrite)
60{
61    /* Input validation */
62    if (!name || SDL_strlen(name) == 0 || SDL_strchr(name, '=') != NULL || !value) {
63        return (-1);
64    }
65    
66    if (!overwrite) {
67        if (GetEnvironmentVariableA(name, NULL, 0) > 0) {
68            return 0;  /* asked not to overwrite existing value. */
69        }
70    }
71    if (!SetEnvironmentVariableA(name, *value ? value : NULL)) {
72        return -1;
73    }
74    return 0;
75}
76/* We have a real environment table, but no real setenv? Fake it w/ putenv. */
77#elif (defined(HAVE_GETENV) && defined(HAVE_PUTENV) && !defined(HAVE_SETENV))
78int
79SDL_setenv(const char *name, const char *value, int overwrite)
80{
81    size_t len;
82    char *new_variable;
83
84    /* Input validation */
85    if (!name || SDL_strlen(name) == 0 || SDL_strchr(name, '=') != NULL || !value) {
86        return (-1);
87    }
88    
89    if (getenv(name) != NULL) {
90        if (overwrite) {
91            unsetenv(name);
92        } else {
93            return 0;  /* leave the existing one there. */
94        }
95    }
96
97    /* This leaks. Sorry. Get a better OS so we don't have to do this. */
98    len = SDL_strlen(name) + SDL_strlen(value) + 2;
99    new_variable = (char *) SDL_malloc(len);
100    if (!new_variable) {
101        return (-1);
102    }
103
104    SDL_snprintf(new_variable, len, "%s=%s", name, value);
105    return putenv(new_variable);
106}
107#else /* roll our own */
108static char **SDL_env = (char **) 0;
109int
110SDL_setenv(const char *name, const char *value, int overwrite)
111{
112    int added;
113    int len, i;
114    char **new_env;
115    char *new_variable;
116
117    /* Input validation */
118    if (!name || SDL_strlen(name) == 0 || SDL_strchr(name, '=') != NULL || !value) {
119        return (-1);
120    }
121
122    /* See if it already exists */
123    if (!overwrite && SDL_getenv(name)) {
124        return 0;
125    }
126
127    /* Allocate memory for the variable */
128    len = SDL_strlen(name) + SDL_strlen(value) + 2;
129    new_variable = (char *) SDL_malloc(len);
130    if (!new_variable) {
131        return (-1);
132    }
133
134    SDL_snprintf(new_variable, len, "%s=%s", name, value);
135    value = new_variable + SDL_strlen(name) + 1;
136    name = new_variable;
137
138    /* Actually put it into the environment */
139    added = 0;
140    i = 0;
141    if (SDL_env) {
142        /* Check to see if it's already there... */
143        len = (value - name);
144        for (; SDL_env[i]; ++i) {
145            if (SDL_strncmp(SDL_env[i], name, len) == 0) {
146                break;
147            }
148        }
149        /* If we found it, just replace the entry */
150        if (SDL_env[i]) {
151            SDL_free(SDL_env[i]);
152            SDL_env[i] = new_variable;
153            added = 1;
154        }
155    }
156
157    /* Didn't find it in the environment, expand and add */
158    if (!added) {
159        new_env = SDL_realloc(SDL_env, (i + 2) * sizeof(char *));
160        if (new_env) {
161            SDL_env = new_env;
162            SDL_env[i++] = new_variable;
163            SDL_env[i++] = (char *) 0;
164            added = 1;
165        } else {
166            SDL_free(new_variable);
167        }
168    }
169    return (added ? 0 : -1);
170}
171#endif
172
173/* Retrieve a variable named "name" from the environment */
174#if defined(HAVE_GETENV)
175char *
176SDL_getenv(const char *name)
177{
178#if defined(__ANDROID__)
179    /* Make sure variables from the application manifest are available */
180    Android_JNI_GetManifestEnvironmentVariables();
181#endif
182
183    /* Input validation */
184    if (!name || !*name) {
185        return NULL;
186    }
187
188    return getenv(name);
189}
190#elif defined(__WIN32__)
191char *
192SDL_getenv(const char *name)
193{
194    size_t bufferlen;
195
196    /* Input validation */
197    if (!name || SDL_strlen(name)==0) {
198        return NULL;
199    }
200    
201    bufferlen =
202        GetEnvironmentVariableA(name, SDL_envmem, (DWORD) SDL_envmemlen);
203    if (bufferlen == 0) {
204        return NULL;
205    }
206    if (bufferlen > SDL_envmemlen) {
207        char *newmem = (char *) SDL_realloc(SDL_envmem, bufferlen);
208        if (newmem == NULL) {
209            return NULL;
210        }
211        SDL_envmem = newmem;
212        SDL_envmemlen = bufferlen;
213        GetEnvironmentVariableA(name, SDL_envmem, (DWORD) SDL_envmemlen);
214    }
215    return SDL_envmem;
216}
217#else
218char *
219SDL_getenv(const char *name)
220{
221    int len, i;
222    char *value;
223
224    /* Input validation */
225    if (!name || SDL_strlen(name)==0) {
226        return NULL;
227    }
228    
229    value = (char *) 0;
230    if (SDL_env) {
231        len = SDL_strlen(name);
232        for (i = 0; SDL_env[i] && !value; ++i) {
233            if ((SDL_strncmp(SDL_env[i], name, len) == 0) &&
234                (SDL_env[i][len] == '=')) {
235                value = &SDL_env[i][len + 1];
236            }
237        }
238    }
239    return value;
240}
241#endif
242
243
244#ifdef TEST_MAIN
245#include <stdio.h>
246
247int
248main(int argc, char *argv[])
249{
250    char *value;
251
252    printf("Checking for non-existent variable... ");
253    fflush(stdout);
254    if (!SDL_getenv("EXISTS")) {
255        printf("okay\n");
256    } else {
257        printf("failed\n");
258    }
259    printf("Setting FIRST=VALUE1 in the environment... ");
260    fflush(stdout);
261    if (SDL_setenv("FIRST", "VALUE1", 0) == 0) {
262        printf("okay\n");
263    } else {
264        printf("failed\n");
265    }
266    printf("Getting FIRST from the environment... ");
267    fflush(stdout);
268    value = SDL_getenv("FIRST");
269    if (value && (SDL_strcmp(value, "VALUE1") == 0)) {
270        printf("okay\n");
271    } else {
272        printf("failed\n");
273    }
274    printf("Setting SECOND=VALUE2 in the environment... ");
275    fflush(stdout);
276    if (SDL_setenv("SECOND", "VALUE2", 0) == 0) {
277        printf("okay\n");
278    } else {
279        printf("failed\n");
280    }
281    printf("Getting SECOND from the environment... ");
282    fflush(stdout);
283    value = SDL_getenv("SECOND");
284    if (value && (SDL_strcmp(value, "VALUE2") == 0)) {
285        printf("okay\n");
286    } else {
287        printf("failed\n");
288    }
289    printf("Setting FIRST=NOVALUE in the environment... ");
290    fflush(stdout);
291    if (SDL_setenv("FIRST", "NOVALUE", 1) == 0) {
292        printf("okay\n");
293    } else {
294        printf("failed\n");
295    }
296    printf("Getting FIRST from the environment... ");
297    fflush(stdout);
298    value = SDL_getenv("FIRST");
299    if (value && (SDL_strcmp(value, "NOVALUE") == 0)) {
300        printf("okay\n");
301    } else {
302        printf("failed\n");
303    }
304    printf("Checking for non-existent variable... ");
305    fflush(stdout);
306    if (!SDL_getenv("EXISTS")) {
307        printf("okay\n");
308    } else {
309        printf("failed\n");
310    }
311    return (0);
312}
313#endif /* TEST_MAIN */
314
315/* vi: set ts=4 sw=4 expandtab: */
316
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