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SDL_getenv.c
271 lines (235 loc) · 6.84 KB
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2009 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_config.h"
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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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#define WIN32_LEAN_AND_MEAN
#include <windows.h>
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/* Note this isn't thread-safe! */
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static char *SDL_envmem = NULL; /* Ugh, memory leak */
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static size_t SDL_envmemlen = 0;
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/* Put a variable into the environment */
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int
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SDL_setenv(const char *name, const char *value, int overwrite)
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{
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if (!overwrite) {
char ch = 0;
const size_t len = GetEnvironmentVariable(name, &ch, sizeof (ch));
if (len > 0) {
return 0; /* asked not to overwrite existing value. */
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}
}
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if (!SetEnvironmentVariable(name, *value ? value : NULL)) {
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return -1;
}
return 0;
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}
/* Retrieve a variable named "name" from the environment */
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char *
SDL_getenv(const char *name)
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{
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size_t bufferlen;
bufferlen =
GetEnvironmentVariable(name, SDL_envmem, (DWORD) SDL_envmemlen);
if (bufferlen == 0) {
return NULL;
}
if (bufferlen > SDL_envmemlen) {
char *newmem = (char *) SDL_realloc(SDL_envmem, bufferlen);
if (newmem == NULL) {
return NULL;
}
SDL_envmem = newmem;
SDL_envmemlen = bufferlen;
GetEnvironmentVariable(name, SDL_envmem, (DWORD) SDL_envmemlen);
}
return SDL_envmem;
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}
#else /* roll our own */
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static char **SDL_env = (char **) 0;
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/* Put a variable into the environment */
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int
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SDL_setenv(const char *name, const char *value, int overwrite)
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{
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int added;
int len, i;
char **new_env;
char *new_variable;
/* A little error checking */
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if (!name || !value) {
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return (-1);
}
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/* See if it already exists */
if (!overwrite && SDL_getenv(name)) {
return 0;
}
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/* Allocate memory for the variable */
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len = SDL_strlen(name) + SDL_strlen(value) + 2;
new_variable = (char *) SDL_malloc(len);
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if (!new_variable) {
return (-1);
}
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SDL_snprintf(new_variable, len, "%s=%s", name, value);
value = new_variable + SDL_strlen(name) + 1;
name = new_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) {
if (SDL_strncmp(SDL_env[i], name, len) == 0) {
break;
}
}
/* If we found it, just replace the entry */
if (SDL_env[i]) {
SDL_free(SDL_env[i]);
SDL_env[i] = new_variable;
added = 1;
}
}
/* Didn't find it in the environment, expand and add */
if (!added) {
new_env = SDL_realloc(SDL_env, (i + 2) * sizeof(char *));
if (new_env) {
SDL_env = new_env;
SDL_env[i++] = new_variable;
SDL_env[i++] = (char *) 0;
added = 1;
} else {
SDL_free(new_variable);
}
}
return (added ? 0 : -1);
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}
/* Retrieve a variable named "name" from the environment */
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char *
SDL_getenv(const char *name)
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{
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int len, i;
char *value;
value = (char *) 0;
if (SDL_env) {
len = SDL_strlen(name);
for (i = 0; SDL_env[i] && !value; ++i) {
if ((SDL_strncmp(SDL_env[i], name, len) == 0) &&
(SDL_env[i][len] == '=')) {
value = &SDL_env[i][len + 1];
}
}
}
return value;
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}
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#endif /* __WIN32__ */
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#endif /* !HAVE_GETENV */
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/* We have a real environment table, but no real setenv? Fake it w/ putenv. */
#if (defined(HAVE_GETENV) && defined(HAVE_PUTENV) && !defined(HAVE_SETENV))
int
SDL_setenv(const char *name, const char *value, int overwrite)
{
size_t len;
char *new_variable;
if (getenv(name) != NULL) {
if (overwrite) {
unsetenv(name);
} else {
return 0; /* leave the existing one there. */
}
}
/* This leaks. Sorry. Get a better OS so we don't have to do this. */
len = SDL_strlen(name) + SDL_strlen(value) + 2;
new_variable = (char *) SDL_malloc(len);
if (!new_variable) {
return (-1);
}
SDL_snprintf(new_variable, len, "%s=%s", name, value);
return putenv(new_variable);
}
#endif
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#ifdef TEST_MAIN
#include <stdio.h>
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int
main(int argc, char *argv[])
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{
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char *value;
printf("Checking for non-existent variable... ");
fflush(stdout);
if (!SDL_getenv("EXISTS")) {
printf("okay\n");
} else {
printf("failed\n");
}
printf("Setting FIRST=VALUE1 in the environment... ");
fflush(stdout);
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if (SDL_setenv("FIRST", "VALUE1", 0) == 0) {
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printf("okay\n");
} else {
printf("failed\n");
}
printf("Getting FIRST from the environment... ");
fflush(stdout);
value = SDL_getenv("FIRST");
if (value && (SDL_strcmp(value, "VALUE1") == 0)) {
printf("okay\n");
} else {
printf("failed\n");
}
printf("Setting SECOND=VALUE2 in the environment... ");
fflush(stdout);
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if (SDL_setenv("SECOND", "VALUE2", 0) == 0) {
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printf("okay\n");
} else {
printf("failed\n");
}
printf("Getting SECOND from the environment... ");
fflush(stdout);
value = SDL_getenv("SECOND");
if (value && (SDL_strcmp(value, "VALUE2") == 0)) {
printf("okay\n");
} else {
printf("failed\n");
}
printf("Setting FIRST=NOVALUE in the environment... ");
fflush(stdout);
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if (SDL_setenv("FIRST", "NOVALUE", 1) == 0) {
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printf("okay\n");
} else {
printf("failed\n");
}
printf("Getting FIRST from the environment... ");
fflush(stdout);
value = SDL_getenv("FIRST");
if (value && (SDL_strcmp(value, "NOVALUE") == 0)) {
printf("okay\n");
} else {
printf("failed\n");
}
printf("Checking for non-existent variable... ");
fflush(stdout);
if (!SDL_getenv("EXISTS")) {
printf("okay\n");
} else {
printf("failed\n");
}
return (0);
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}
#endif /* TEST_MAIN */
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/* vi: set ts=4 sw=4 expandtab: */