view src/stdlib/SDL_getenv.c @ 1879:cb232e63552c

Default the X11 dynamically loading on if the OS loader loads libraries with their private symbols hidden. If that isn't the case, and someone tries to enable it anyway, spit out a warning and don't let them do it.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 23 Jun 2006 08:39:05 +0000
parents 4aac8563c296
children 782fd950bd46 c121d94672cb e85e65aec22f
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    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
    Lesser General Public License for more details.

    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

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

#include "SDL_stdinc.h"

#ifndef HAVE_GETENV

#if defined(__WIN32__) && !defined(_WIN32_WCE)

#define WIN32_LEAN_AND_MEAN
#include <windows.h>

/* Note this isn't thread-safe! */

static char *SDL_envmem = NULL;	/* Ugh, memory leak */
static size_t SDL_envmemlen = 0;

/* Put a variable of the form "name=value" into the environment */
int SDL_putenv(const char *variable)
{
	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;
}

/* Retrieve a variable named "name" from the environment */
char *SDL_getenv(const char *name)
{
	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;
}

#else /* roll our own */

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 */
	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);
}

/* 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 ) {
		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;
}

#endif /* __WIN32__ */

#endif /* !HAVE_GETENV */

#ifdef TEST_MAIN
#include <stdio.h>

int main(int argc, char *argv[])
{
	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);
}
#endif /* TEST_MAIN */