src/stdlib/SDL_getenv.c
changeset 1330 450721ad5436
child 1331 1cbaeee565b1
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/stdlib/SDL_getenv.c	Mon Feb 06 08:28:51 2006 +0000
@@ -0,0 +1,245 @@
+/*
+    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_stdlib.h"
+#include "SDL_string.h"
+
+
+#if defined(WIN32) && !defined(_WIN32_WCE)
+
+#include "SDL_windows.h"
+#include "SDL_string.h"
+
+/* 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;
+
+	sep = strchr(variable, '=');
+	if ( sep == NULL ) {
+		return -1;
+	}
+	bufferlen = strlen(variable)+1;
+	if ( bufferlen > SDL_envmemlen ) {
+		char *newmem = (char *)realloc(SDL_envmem, bufferlen);
+		if ( newmem == NULL ) {
+			return -1;
+		}
+		SDL_envmem = newmem;
+		SDL_envmemlen = bufferlen;
+	}
+	strcpy(SDL_envmem, variable);
+	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 ) {
+		char *newmem = (char *)realloc(SDL_envmem, bufferlen);
+		if ( newmem == NULL ) {
+			return NULL;
+		}
+		SDL_envmem = newmem;
+		SDL_envmemlen = bufferlen;
+		GetEnvironmentVariable(name, SDL_envmem, 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 = (char *)malloc(strlen(variable)+1);
+	if ( ! new_variable ) {
+		return(-1);
+	}
+	strcpy(new_variable, variable);
+
+	/* 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 ( strncmp(SDL_env[i], name, len) == 0 ) {
+				break;
+			}
+		}
+		/* If we found it, just replace the entry */
+		if ( SDL_env[i] ) {
+			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 = 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 {
+			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 = strlen(name);
+		for ( i=0; SDL_env[i] && !value; ++i ) {
+			if ( (strncmp(SDL_env[i], name, len) == 0) &&
+			     (SDL_env[i][len] == '=') ) {
+				value = &SDL_env[i][len+1];
+			}
+		}
+	}
+	return value;
+}
+
+#endif /* WIN32 */
+
+#ifdef TEST_MAIN
+#include <stdio.h>
+
+int main(int argc, char *argv[])
+{
+	char *value;
+
+	printf("Checking for non-existent variable... ");
+	fflush(stdout);
+	if ( ! getenv("EXISTS") ) {
+		printf("okay\n");
+	} else {
+		printf("failed\n");
+	}
+	printf("Setting FIRST=VALUE1 in the environment... ");
+	fflush(stdout);
+	if ( putenv("FIRST=VALUE1") == 0 ) {
+		printf("okay\n");
+	} else {
+		printf("failed\n");
+	}
+	printf("Getting FIRST from the environment... ");
+	fflush(stdout);
+	value = getenv("FIRST");
+	if ( value && (strcmp(value, "VALUE1") == 0) ) {
+		printf("okay\n");
+	} else {
+		printf("failed\n");
+	}
+	printf("Setting SECOND=VALUE2 in the environment... ");
+	fflush(stdout);
+	if ( putenv("SECOND=VALUE2") == 0 ) {
+		printf("okay\n");
+	} else {
+		printf("failed\n");
+	}
+	printf("Getting SECOND from the environment... ");
+	fflush(stdout);
+	value = getenv("SECOND");
+	if ( value && (strcmp(value, "VALUE2") == 0) ) {
+		printf("okay\n");
+	} else {
+		printf("failed\n");
+	}
+	printf("Setting FIRST=NOVALUE in the environment... ");
+	fflush(stdout);
+	if ( putenv("FIRST=NOVALUE") == 0 ) {
+		printf("okay\n");
+	} else {
+		printf("failed\n");
+	}
+	printf("Getting FIRST from the environment... ");
+	fflush(stdout);
+	value = getenv("FIRST");
+	if ( value && (strcmp(value, "NOVALUE") == 0) ) {
+		printf("okay\n");
+	} else {
+		printf("failed\n");
+	}
+	printf("Checking for non-existent variable... ");
+	fflush(stdout);
+	if ( ! getenv("EXISTS") ) {
+		printf("okay\n");
+	} else {
+		printf("failed\n");
+	}
+	return(0);
+}
+#endif /* TEST_MAIN */
+