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SDL_getenv.c
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2006 Sam Lantinga
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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Sam Lantinga
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slouken@libsdl.org
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*/
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#include "SDL_stdinc.h"
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#ifndef HAVE_GETENV
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#if defined(WIN32) && !defined(_WIN32_WCE)
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#include "SDL_windows.h"
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/* Note this isn't thread-safe! */
static char *SDL_envmem = NULL; /* Ugh, memory leak */
static DWORD SDL_envmemlen = 0;
/* Put a variable of the form "name=value" into the environment */
int SDL_putenv(const char *variable)
{
DWORD bufferlen;
char *value;
const char *sep;
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sep = SDL_strchr(variable, '=');
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if ( sep == NULL ) {
return -1;
}
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bufferlen = SDL_strlen(variable)+1;
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if ( bufferlen > SDL_envmemlen ) {
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char *newmem = (char *)SDL_realloc(SDL_envmem, bufferlen);
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if ( newmem == NULL ) {
return -1;
}
SDL_envmem = newmem;
SDL_envmemlen = bufferlen;
}
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SDL_strcpy(SDL_envmem, variable);
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value = SDL_envmem + (sep - variable);
*value++ = '\0';
if ( !SetEnvironmentVariable(SDL_envmem, *value ? value : NULL) ) {
return -1;
}
return 0;
}
/* Retrieve a variable named "name" from the environment */
char *SDL_getenv(const char *name)
{
DWORD bufferlen;
bufferlen = GetEnvironmentVariable(name, SDL_envmem, SDL_envmemlen);
if ( bufferlen == 0 ) {
return NULL;
}
if ( bufferlen > SDL_envmemlen ) {
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char *newmem = (char *)SDL_realloc(SDL_envmem, bufferlen);
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if ( newmem == NULL ) {
return NULL;
}
SDL_envmem = newmem;
SDL_envmemlen = bufferlen;
GetEnvironmentVariable(name, SDL_envmem, SDL_envmemlen);
}
return SDL_envmem;
}
#else /* roll our own */
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static char **SDL_env = (char **)0;
/* Put a variable of the form "name=value" into the environment */
int SDL_putenv(const char *variable)
{
const char *name, *value;
int added;
int len, i;
char **new_env;
char *new_variable;
/* A little error checking */
if ( ! variable ) {
return(-1);
}
name = variable;
for ( value=variable; *value && (*value != '='); ++value ) {
/* Keep looking for '=' */ ;
}
if ( *value ) {
++value;
} else {
return(-1);
}
/* Allocate memory for the variable */
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new_variable = (char *)SDL_malloc(SDL_strlen(variable)+1);
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if ( ! new_variable ) {
return(-1);
}
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SDL_strcpy(new_variable, variable);
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/* Actually put it into the environment */
added = 0;
i = 0;
if ( SDL_env ) {
/* Check to see if it's already there... */
len = (value - name);
for ( ; SDL_env[i]; ++i ) {
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if ( SDL_strncmp(SDL_env[i], name, len) == 0 ) {
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break;
}
}
/* If we found it, just replace the entry */
if ( SDL_env[i] ) {
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SDL_free(SDL_env[i]);
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SDL_env[i] = new_variable;
added = 1;
}
}
/* Didn't find it in the environment, expand and add */
if ( ! added ) {
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new_env = SDL_realloc(SDL_env, (i+2)*sizeof(char *));
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if ( new_env ) {
SDL_env = new_env;
SDL_env[i++] = new_variable;
SDL_env[i++] = (char *)0;
added = 1;
} else {
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SDL_free(new_variable);
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}
}
return (added ? 0 : -1);
}
/* Retrieve a variable named "name" from the environment */
char *SDL_getenv(const char *name)
{
int len, i;
char *value;
value = (char *)0;
if ( SDL_env ) {
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len = SDL_strlen(name);
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for ( i=0; SDL_env[i] && !value; ++i ) {
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if ( (SDL_strncmp(SDL_env[i], name, len) == 0) &&
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(SDL_env[i][len] == '=') ) {
value = &SDL_env[i][len+1];
}
}
}
return value;
}
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#endif /* WIN32 */
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#endif /* !HAVE_GETENV */
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#ifdef TEST_MAIN
#include <stdio.h>
int main(int argc, char *argv[])
{
char *value;
printf("Checking for non-existent variable... ");
fflush(stdout);
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if ( ! SDL_getenv("EXISTS") ) {
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printf("okay\n");
} else {
printf("failed\n");
}
printf("Setting FIRST=VALUE1 in the environment... ");
fflush(stdout);
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if ( SDL_putenv("FIRST=VALUE1") == 0 ) {
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printf("okay\n");
} else {
printf("failed\n");
}
printf("Getting FIRST from the environment... ");
fflush(stdout);
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value = SDL_getenv("FIRST");
if ( value && (SDL_strcmp(value, "VALUE1") == 0) ) {
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printf("okay\n");
} else {
printf("failed\n");
}
printf("Setting SECOND=VALUE2 in the environment... ");
fflush(stdout);
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if ( SDL_putenv("SECOND=VALUE2") == 0 ) {
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printf("okay\n");
} else {
printf("failed\n");
}
printf("Getting SECOND from the environment... ");
fflush(stdout);
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value = SDL_getenv("SECOND");
if ( value && (SDL_strcmp(value, "VALUE2") == 0) ) {
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printf("okay\n");
} else {
printf("failed\n");
}
printf("Setting FIRST=NOVALUE in the environment... ");
fflush(stdout);
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if ( SDL_putenv("FIRST=NOVALUE") == 0 ) {
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printf("okay\n");
} else {
printf("failed\n");
}
printf("Getting FIRST from the environment... ");
fflush(stdout);
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value = SDL_getenv("FIRST");
if ( value && (SDL_strcmp(value, "NOVALUE") == 0) ) {
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printf("okay\n");
} else {
printf("failed\n");
}
printf("Checking for non-existent variable... ");
fflush(stdout);
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if ( ! SDL_getenv("EXISTS") ) {
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printf("okay\n");
} else {
printf("failed\n");
}
return(0);
}
#endif /* TEST_MAIN */