Initial commit of upstream NSPR (4.7.3) and NSS3 (3.12).

third_party/nspr/mozilla/nsprpub/pr/include/prenv.h

Index: third_party/nspr/mozilla/nsprpub/pr/include/prenv.h
diff --git a/third_party/nspr/mozilla/nsprpub/pr/include/prenv.h b/third_party/nspr/mozilla/nsprpub/pr/include/prenv.h
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index 0000000000000000000000000000000000000000..2cae7d79eea73593578f035e879071e4e26fc984
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+++ b/third_party/nspr/mozilla/nsprpub/pr/include/prenv.h
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is the Netscape Portable Runtime (NSPR).
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1998-2000
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef prenv_h___
+#define prenv_h___
+
+#include "prtypes.h"
+
+/*******************************************************************************/
+/*******************************************************************************/
+/****************** THESE FUNCTIONS MAY NOT BE THREAD SAFE *********************/
+/*******************************************************************************/
+/*******************************************************************************/
+
+PR_BEGIN_EXTERN_C
+
+/*
+** PR_GetEnv() -- Retrieve value of environment variable
+** 
+** Description:
+** PR_GetEnv() is modeled on Unix getenv().
+** 
+** 
+** Inputs: 
+**   var -- The name of the environment variable
+** 
+** Returns:
+**   The value of the environment variable 'var' or NULL if
+** the variable is undefined.
+** 
+** Restrictions:
+**   You'd think that a POSIX getenv(), putenv() would be
+**   consistently implemented everywhere. Surprise! It is not. On
+**   some platforms, a putenv() where the argument is of
+**   the form "name"  causes the named environment variable to
+**   be un-set; that is: a subsequent getenv() returns NULL. On
+**   other platforms, the putenv() fails, on others, it is a
+**   no-op. Similarly, a putenv() where the argument is of the
+**   form "name=" causes the named environment variable to be
+**   un-set; a subsequent call to getenv() returns NULL. On
+**   other platforms, a subsequent call to getenv() returns a
+**   pointer to a null-string (a byte of zero).
+** 
+**   PR_GetEnv(), PR_SetEnv() provide a consistent behavior 
+**   across all supported platforms. There are, however, some
+**   restrictions and some practices you must use to achieve
+**   consistent results everywhere.
+** 
+**   When manipulating the environment there is no way to un-set
+**   an environment variable across all platforms. We suggest
+**   you interpret the return of a pointer to null-string to
+**   mean the same as a return of NULL from PR_GetEnv().
+** 
+**   A call to PR_SetEnv() where the parameter is of the form
+**   "name" will return PR_FAILURE; the environment remains
+**   unchanged. A call to PR_SetEnv() where the parameter is
+**   of the form "name=" may un-set the envrionment variable on
+**   some platforms; on others it may set the value of the
+**   environment variable to the null-string.
+** 
+**   For example, to test for NULL return or return of the
+**   null-string from PR_GetEnv(), use the following code
+**   fragment:
+** 
+**      char *val = PR_GetEnv("foo");
+**      if ((NULL == val) || ('\0' == *val)) { 
+**          ... interpret this as un-set ... 
+**      }
+** 
+**   The caller must ensure that the string passed
+**   to PR_SetEnv() is persistent. That is: The string should
+**   not be on the stack, where it can be overwritten
+**   on return from the function calling PR_SetEnv().
+**   Similarly, the string passed to PR_SetEnv() must not be
+**   overwritten by other actions of the process. ... Some
+**   platforms use the string by reference rather than copying
+**   it into the environment space. ... You have been warned!
+** 
+**   Use of platform-native functions that manipulate the
+**   environment (getenv(), putenv(), 
+**   SetEnvironmentVariable(), etc.) must not be used with
+**   NSPR's similar functions. The platform-native functions
+**   may not be thread safe and/or may operate on different
+**   conceptual environment space than that operated upon by
+**   NSPR's functions or other environment manipulating
+**   functions on the same platform. (!)
+** 
+*/
+NSPR_API(char*) PR_GetEnv(const char *var);
+
+/*
+** PR_SetEnv() -- set, unset or change an environment variable
+** 
+** Description:
+** PR_SetEnv() is modeled on the Unix putenv() function.
+** 
+** Inputs: 
+**   string -- pointer to a caller supplied
+**   constant, persistent string of the form name=value. Where
+**   name is the name of the environment variable to be set or
+**   changed; value is the value assigned to the variable.
+**
+** Returns: 
+**   PRStatus.
+** 
+** Restrictions: 
+**   See the Restrictions documented in the description of
+**   PR_GetEnv() in this header file.
+** 
+** 
+*/
+NSPR_API(PRStatus) PR_SetEnv(const char *string);
+
+/*
+** DEPRECATED.  Use PR_SetEnv() instead.
+*/
+#ifdef XP_MAC
+NSPR_API(PRIntn) PR_PutEnv(const char *string);
+#endif
+
+PR_END_EXTERN_C
+
+#endif /* prenv_h___ */