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comparison src/stdlib/SDL_getenv.c @ 1330:450721ad5436

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It's now possible to build SDL without any C runtime at all on Windows, using Visual C++ 2005
author Sam Lantinga <slouken@libsdl.org>
date Mon, 06 Feb 2006 08:28:51 +0000
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children 1cbaeee565b1
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1329:bc67bbf87818 1330:450721ad5436
1 /*
2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997-2006 Sam Lantinga
4
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with this library; if not, write to the Free Software
17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18
19 Sam Lantinga
20 slouken@libsdl.org
21 */
22
23 #include "SDL_stdlib.h"
24 #include "SDL_string.h"
25
26
27 #if defined(WIN32) && !defined(_WIN32_WCE)
28
29 #include "SDL_windows.h"
30 #include "SDL_string.h"
31
32 /* Note this isn't thread-safe! */
33
34 static char *SDL_envmem = NULL; /* Ugh, memory leak */
35 static DWORD SDL_envmemlen = 0;
36
37 /* Put a variable of the form "name=value" into the environment */
38 int SDL_putenv(const char *variable)
39 {
40 DWORD bufferlen;
41 char *value;
42 const char *sep;
43
44 sep = strchr(variable, '=');
45 if ( sep == NULL ) {
46 return -1;
47 }
48 bufferlen = strlen(variable)+1;
49 if ( bufferlen > SDL_envmemlen ) {
50 char *newmem = (char *)realloc(SDL_envmem, bufferlen);
51 if ( newmem == NULL ) {
52 return -1;
53 }
54 SDL_envmem = newmem;
55 SDL_envmemlen = bufferlen;
56 }
57 strcpy(SDL_envmem, variable);
58 value = SDL_envmem + (sep - variable);
59 *value++ = '\0';
60 if ( !SetEnvironmentVariable(SDL_envmem, *value ? value : NULL) ) {
61 return -1;
62 }
63 return 0;
64 }
65
66 /* Retrieve a variable named "name" from the environment */
67 char *SDL_getenv(const char *name)
68 {
69 DWORD bufferlen;
70
71 bufferlen = GetEnvironmentVariable(name, SDL_envmem, SDL_envmemlen);
72 if ( bufferlen == 0 ) {
73 return NULL;
74 }
75 if ( bufferlen > SDL_envmemlen ) {
76 char *newmem = (char *)realloc(SDL_envmem, bufferlen);
77 if ( newmem == NULL ) {
78 return NULL;
79 }
80 SDL_envmem = newmem;
81 SDL_envmemlen = bufferlen;
82 GetEnvironmentVariable(name, SDL_envmem, SDL_envmemlen);
83 }
84 return SDL_envmem;
85 }
86
87 #else /* roll our own */
88
89 static char **SDL_env = (char **)0;
90
91 /* Put a variable of the form "name=value" into the environment */
92 int SDL_putenv(const char *variable)
93 {
94 const char *name, *value;
95 int added;
96 int len, i;
97 char **new_env;
98 char *new_variable;
99
100 /* A little error checking */
101 if ( ! variable ) {
102 return(-1);
103 }
104 name = variable;
105 for ( value=variable; *value && (*value != '='); ++value ) {
106 /* Keep looking for '=' */ ;
107 }
108 if ( *value ) {
109 ++value;
110 } else {
111 return(-1);
112 }
113
114 /* Allocate memory for the variable */
115 new_variable = (char *)malloc(strlen(variable)+1);
116 if ( ! new_variable ) {
117 return(-1);
118 }
119 strcpy(new_variable, variable);
120
121 /* Actually put it into the environment */
122 added = 0;
123 i = 0;
124 if ( SDL_env ) {
125 /* Check to see if it's already there... */
126 len = (value - name);
127 for ( ; SDL_env[i]; ++i ) {
128 if ( strncmp(SDL_env[i], name, len) == 0 ) {
129 break;
130 }
131 }
132 /* If we found it, just replace the entry */
133 if ( SDL_env[i] ) {
134 free(SDL_env[i]);
135 SDL_env[i] = new_variable;
136 added = 1;
137 }
138 }
139
140 /* Didn't find it in the environment, expand and add */
141 if ( ! added ) {
142 new_env = realloc(SDL_env, (i+2)*sizeof(char *));
143 if ( new_env ) {
144 SDL_env = new_env;
145 SDL_env[i++] = new_variable;
146 SDL_env[i++] = (char *)0;
147 added = 1;
148 } else {
149 free(new_variable);
150 }
151 }
152 return (added ? 0 : -1);
153 }
154
155 /* Retrieve a variable named "name" from the environment */
156 char *SDL_getenv(const char *name)
157 {
158 int len, i;
159 char *value;
160
161 value = (char *)0;
162 if ( SDL_env ) {
163 len = strlen(name);
164 for ( i=0; SDL_env[i] && !value; ++i ) {
165 if ( (strncmp(SDL_env[i], name, len) == 0) &&
166 (SDL_env[i][len] == '=') ) {
167 value = &SDL_env[i][len+1];
168 }
169 }
170 }
171 return value;
172 }
173
174 #endif /* WIN32 */
175
176 #ifdef TEST_MAIN
177 #include <stdio.h>
178
179 int main(int argc, char *argv[])
180 {
181 char *value;
182
183 printf("Checking for non-existent variable... ");
184 fflush(stdout);
185 if ( ! getenv("EXISTS") ) {
186 printf("okay\n");
187 } else {
188 printf("failed\n");
189 }
190 printf("Setting FIRST=VALUE1 in the environment... ");
191 fflush(stdout);
192 if ( putenv("FIRST=VALUE1") == 0 ) {
193 printf("okay\n");
194 } else {
195 printf("failed\n");
196 }
197 printf("Getting FIRST from the environment... ");
198 fflush(stdout);
199 value = getenv("FIRST");
200 if ( value && (strcmp(value, "VALUE1") == 0) ) {
201 printf("okay\n");
202 } else {
203 printf("failed\n");
204 }
205 printf("Setting SECOND=VALUE2 in the environment... ");
206 fflush(stdout);
207 if ( putenv("SECOND=VALUE2") == 0 ) {
208 printf("okay\n");
209 } else {
210 printf("failed\n");
211 }
212 printf("Getting SECOND from the environment... ");
213 fflush(stdout);
214 value = getenv("SECOND");
215 if ( value && (strcmp(value, "VALUE2") == 0) ) {
216 printf("okay\n");
217 } else {
218 printf("failed\n");
219 }
220 printf("Setting FIRST=NOVALUE in the environment... ");
221 fflush(stdout);
222 if ( putenv("FIRST=NOVALUE") == 0 ) {
223 printf("okay\n");
224 } else {
225 printf("failed\n");
226 }
227 printf("Getting FIRST from the environment... ");
228 fflush(stdout);
229 value = getenv("FIRST");
230 if ( value && (strcmp(value, "NOVALUE") == 0) ) {
231 printf("okay\n");
232 } else {
233 printf("failed\n");
234 }
235 printf("Checking for non-existent variable... ");
236 fflush(stdout);
237 if ( ! getenv("EXISTS") ) {
238 printf("okay\n");
239 } else {
240 printf("failed\n");
241 }
242 return(0);
243 }
244 #endif /* TEST_MAIN */
245