src/stdlib/SDL_getenv.c - third_party/sdl - Git at Google

 /*
   Simple DirectMedia Layer
   Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>

   This software is provided 'as-is', without any express or implied
   warranty.  In no event will the authors be held liable for any damages
   arising from the use of this software.

   Permission is granted to anyone to use this software for any purpose,
   including commercial applications, and to alter it and redistribute it
   freely, subject to the following restrictions:

   1. The origin of this software must not be misrepresented; you must not
      claim that you wrote the original software. If you use this software
      in a product, an acknowledgment in the product documentation would be
      appreciated but is not required.
   2. Altered source versions must be plainly marked as such, and must not be
      misrepresented as being the original software.
   3. This notice may not be removed or altered from any source distribution.
 */

 #if defined(__clang_analyzer__) && !defined(SDL_DISABLE_ANALYZE_MACROS)
 #define SDL_DISABLE_ANALYZE_MACROS 1
 #endif

 #include "../SDL_internal.h"

 #if defined(__WIN32__)
 #include "../core/windows/SDL_windows.h"
 #endif

 #if defined(__ANDROID__)
 #include "../core/android/SDL_android.h"
 #endif

 #include "SDL_stdinc.h"

 #if defined(__WIN32__) && (!defined(HAVE_SETENV) || !defined(HAVE_GETENV))
 /* Note this isn't thread-safe! */
 static char *SDL_envmem = NULL; /* Ugh, memory leak */
 static size_t SDL_envmemlen = 0;
 #endif

 /* Put a variable into the environment */
 /* Note: Name may not contain a '=' character. (Reference: http://www.unix.com/man-page/Linux/3/setenv/) */
 #if defined(HAVE_SETENV)
 int
 SDL_setenv(const char *name, const char *value, int overwrite)
 {
     /* Input validation */
     if (!name || SDL_strlen(name) == 0 || SDL_strchr(name, '=') != NULL || !value) {
         return (-1);
     }

     return setenv(name, value, overwrite);
 }
 #elif defined(__WIN32__)
 int
 SDL_setenv(const char *name, const char *value, int overwrite)
 {
     /* Input validation */
     if (!name || SDL_strlen(name) == 0 || SDL_strchr(name, '=') != NULL || !value) {
         return (-1);
     }

     if (!overwrite) {
         if (GetEnvironmentVariableA(name, NULL, 0) > 0) {
             return 0;  /* asked not to overwrite existing value. */
         }
     }
     if (!SetEnvironmentVariableA(name, *value ? value : NULL)) {
         return -1;
     }
     return 0;
 }
 /* We have a real environment table, but no real setenv? Fake it w/ putenv. */
 #elif (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;

     /* Input validation */
     if (!name || SDL_strlen(name) == 0 || SDL_strchr(name, '=') != NULL || !value) {
         return (-1);
     }

     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);
 }
 #else /* roll our own */
 static char **SDL_env = (char **) 0;
 int
 SDL_setenv(const char *name, const char *value, int overwrite)
 {
     int added;
     size_t len, i;
     char **new_env;
     char *new_variable;

     /* Input validation */
     if (!name || SDL_strlen(name) == 0 || SDL_strchr(name, '=') != NULL || !value) {
         return (-1);
     }

     /* See if it already exists */
     if (!overwrite && SDL_getenv(name)) {
         return 0;
     }

     /* Allocate memory for the variable */
     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);
     value = new_variable + SDL_strlen(name) + 1;
     name = new_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 (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);
 }
 #endif

 /* Retrieve a variable named "name" from the environment */
 #if defined(HAVE_GETENV)
 char *
 SDL_getenv(const char *name)
 {
 #if defined(__ANDROID__)
     /* Make sure variables from the application manifest are available */
     Android_JNI_GetManifestEnvironmentVariables();
 #endif

     /* Input validation */
     if (!name || !*name) {
         return NULL;
     }

     return getenv(name);
 }
 #elif defined(__WIN32__)
 char *
 SDL_getenv(const char *name)
 {
     size_t bufferlen;

     /* Input validation */
     if (!name || SDL_strlen(name)==0) {
         return NULL;
     }

     bufferlen =
         GetEnvironmentVariableA(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;
         GetEnvironmentVariableA(name, SDL_envmem, (DWORD) SDL_envmemlen);
     }
     return SDL_envmem;
 }
 #else
 char *
 SDL_getenv(const char *name)
 {
     size_t len, i;
     char *value;

     /* Input validation */
     if (!name || SDL_strlen(name)==0) {
         return NULL;
     }

     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


 #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_setenv("FIRST", "VALUE1", 0) == 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_setenv("SECOND", "VALUE2", 0) == 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_setenv("FIRST", "NOVALUE", 1) == 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 */

 /* vi: set ts=4 sw=4 expandtab: */
	/*
	Simple DirectMedia Layer
	Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>

	This software is provided 'as-is', without any express or implied
	warranty. In no event will the authors be held liable for any damages
	arising from the use of this software.

	Permission is granted to anyone to use this software for any purpose,
	including commercial applications, and to alter it and redistribute it
	freely, subject to the following restrictions:

	1. The origin of this software must not be misrepresented; you must not
	claim that you wrote the original software. If you use this software
	in a product, an acknowledgment in the product documentation would be
	appreciated but is not required.
	2. Altered source versions must be plainly marked as such, and must not be
	misrepresented as being the original software.
	3. This notice may not be removed or altered from any source distribution.
	*/

	#if defined(__clang_analyzer__) && !defined(SDL_DISABLE_ANALYZE_MACROS)
	#define SDL_DISABLE_ANALYZE_MACROS 1
	#endif

	#include "../SDL_internal.h"

	#if defined(__WIN32__)
	#include "../core/windows/SDL_windows.h"
	#endif

	#if defined(__ANDROID__)
	#include "../core/android/SDL_android.h"
	#endif

	#include "SDL_stdinc.h"

	#if defined(__WIN32__) && (!defined(HAVE_SETENV) \|\| !defined(HAVE_GETENV))
	/* Note this isn't thread-safe! */
	static char SDL_envmem = NULL; / Ugh, memory leak */
	static size_t SDL_envmemlen = 0;
	#endif

	/* Put a variable into the environment */
	/* Note: Name may not contain a '=' character. (Reference: http://www.unix.com/man-page/Linux/3/setenv/) */
	#if defined(HAVE_SETENV)
	int
	SDL_setenv(const char name, const char value, int overwrite)
	{
	/* Input validation */
	if (!name \|\| SDL_strlen(name) == 0 \|\| SDL_strchr(name, '=') != NULL \|\| !value) {
	return (-1);
	}

	return setenv(name, value, overwrite);
	}
	#elif defined(__WIN32__)
	int
	SDL_setenv(const char name, const char value, int overwrite)
	{
	/* Input validation */
	if (!name \|\| SDL_strlen(name) == 0 \|\| SDL_strchr(name, '=') != NULL \|\| !value) {
	return (-1);
	}

	if (!overwrite) {
	if (GetEnvironmentVariableA(name, NULL, 0) > 0) {
	return 0; /* asked not to overwrite existing value. */
	}
	}
	if (!SetEnvironmentVariableA(name, *value ? value : NULL)) {
	return -1;
	}
	return 0;
	}
	/* We have a real environment table, but no real setenv? Fake it w/ putenv. */
	#elif (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;

	/* Input validation */
	if (!name \|\| SDL_strlen(name) == 0 \|\| SDL_strchr(name, '=') != NULL \|\| !value) {
	return (-1);
	}

	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);
	}
	#else /* roll our own */
	static char SDL_env = (char ) 0;
	int
	SDL_setenv(const char name, const char value, int overwrite)
	{
	int added;
	size_t len, i;
	char **new_env;
	char *new_variable;

	/* Input validation */
	if (!name \|\| SDL_strlen(name) == 0 \|\| SDL_strchr(name, '=') != NULL \|\| !value) {
	return (-1);
	}

	/* See if it already exists */
	if (!overwrite && SDL_getenv(name)) {
	return 0;
	}

	/* Allocate memory for the variable */
	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);
	value = new_variable + SDL_strlen(name) + 1;
	name = new_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 (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);
	}
	#endif

	/* Retrieve a variable named "name" from the environment */
	#if defined(HAVE_GETENV)
	char *
	SDL_getenv(const char *name)
	{
	#if defined(__ANDROID__)
	/* Make sure variables from the application manifest are available */
	Android_JNI_GetManifestEnvironmentVariables();
	#endif

	/* Input validation */
	if (!name \|\| !*name) {
	return NULL;
	}

	return getenv(name);
	}
	#elif defined(__WIN32__)
	char *
	SDL_getenv(const char *name)
	{
	size_t bufferlen;

	/* Input validation */
	if (!name \|\| SDL_strlen(name)==0) {
	return NULL;
	}

	bufferlen =
	GetEnvironmentVariableA(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;
	GetEnvironmentVariableA(name, SDL_envmem, (DWORD) SDL_envmemlen);
	}
	return SDL_envmem;
	}
	#else
	char *
	SDL_getenv(const char *name)
	{
	size_t len, i;
	char *value;

	/* Input validation */
	if (!name \|\| SDL_strlen(name)==0) {
	return NULL;
	}

	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


	#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_setenv("FIRST", "VALUE1", 0) == 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_setenv("SECOND", "VALUE2", 0) == 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_setenv("FIRST", "NOVALUE", 1) == 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 */

	/* vi: set ts=4 sw=4 expandtab: */