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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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#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 of the form "name=value" into the environment */
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int
SDL_putenv (const char *variable)
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size_t bufferlen;
char *value;
const char *sep;
sep = SDL_strchr (variable, '=');
if (sep == NULL) {
return -1;
}
bufferlen = SDL_strlen (variable) + 1;
if (bufferlen > SDL_envmemlen) {
char *newmem = (char *) SDL_realloc (SDL_envmem, bufferlen);
if (newmem == NULL) {
return -1;
}
SDL_envmem = newmem;
SDL_envmemlen = bufferlen;
}
SDL_strlcpy (SDL_envmem, variable, bufferlen);
value = SDL_envmem + (sep - variable);
*value++ = '\0';
if (!SetEnvironmentVariable (SDL_envmem, *value ? value : NULL)) {
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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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 of the form "name=value" into the environment */
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int
SDL_putenv (const char *variable)
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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 */
new_variable = SDL_strdup (variable);
if (!new_variable) {
return (-1);
}
/* 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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#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);
if (SDL_putenv ("FIRST=VALUE1") == 0) {
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);
if (SDL_putenv ("SECOND=VALUE2") == 0) {
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);
if (SDL_putenv ("FIRST=NOVALUE") == 0) {
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: */