src/stdlib/SDL_getenv.c
changeset 1330 450721ad5436
child 1331 1cbaeee565b1
equal deleted inserted replaced
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