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openmpi/opal/util/opal_environ.h
2015-06-23 20:59:57 -07:00

145 строки
4.8 KiB
C

/*
* Copyright (c) 2004-2007 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2005 The University of Tennessee and The University
* of Tennessee Research Foundation. All rights
* reserved.
* Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
* University of Stuttgart. All rights reserved.
* Copyright (c) 2004-2005 The Regents of the University of California.
* All rights reserved.
* Copyright (c) 2007-2013 Los Alamos National Security, LLC. All rights
* reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
/**
* @file
*
* Generic helper routines for environment manipulation.
*/
#ifndef OPAL_ENVIRON_H
#define OPAL_ENVIRON_H
#include "opal_config.h"
#ifdef HAVE_CRT_EXTERNS_H
#include <crt_externs.h>
#endif
BEGIN_C_DECLS
/**
* Merge two environ-like arrays into a single, new array, ensuring
* that there are no duplicate entries.
*
* @param minor Set 1 of the environ's to merge
* @param major Set 2 of the environ's to merge
* @retval New array of environ
*
* Merge two environ-like arrays into a single, new array,
* ensuring that there are no duplicate entires. If there are
* duplicates, entries in the \em major array are favored over
* those in the \em minor array.
*
* Both \em major and \em minor are expected to be argv-style
* arrays (i.e., terminated with a NULL pointer).
*
* The array that is returned is an unencumbered array that should
* later be freed with a call to opal_argv_free().
*
* Either (or both) of \em major and \em minor can be NULL. If
* one of the two is NULL, the other list is simply copied to the
* output. If both are NULL, NULL is returned.
*/
OPAL_DECLSPEC char **opal_environ_merge(char **minor, char **major) __opal_attribute_warn_unused_result__;
/**
* Portable version of setenv(3), allowing editing of any
* environ-like array.
*
* @param name String name of the environment variable to look for
* @param value String value to set (may be NULL)
* @param overwrite Whether to overwrite any existing value with
* the same name
* @param env The environment to use
*
* @retval OPAL_ERR_OUT_OF_RESOURCE If internal malloc() fails.
* @retval OPAL_EXISTS If the name already exists in \em env and
* \em overwrite is false (and therefore the \em value was not
* saved in \em env)
* @retval OPAL_SUCESS If the value replaced another value or is
* appended to \em env.
*
* \em env is expected to be a NULL-terminated array of pointers
* (argv-style). Note that unlike some implementations of
* putenv(3), if \em value is insertted in \em env, it is copied.
* So the caller can modify/free both \em name and \em value after
* opal_setenv() returns.
*
* The \em env array will be grown if necessary.
*
* It is permissable to invoke this function with the
* system-defined \em environ variable. For example:
*
* \code
* #include "opal/util/opal_environ.h"
* opal_setenv("foo", "bar", true, &environ);
* \endcode
*
* NOTE: If you use the real environ, opal_setenv() will turn
* around and perform putenv() to put the value in the
* environment. This may very well lead to a memory leak, so its
* use is strongly discouraged.
*
* It is also permissable to call this function with an empty \em
* env, as long as it is pre-initialized with NULL:
*
* \code
* char **my_env = NULL;
* opal_setenv("foo", "bar", true, &my_env);
* \endcode
*/
OPAL_DECLSPEC int opal_setenv(const char *name, const char *value,
bool overwrite, char ***env) __opal_attribute_nonnull__(1);
/**
* Portable version of unsetenv(3), allowing editing of any
* environ-like array.
*
* @param name String name of the environment variable to look for
* @param env The environment to use
*
* @retval OPAL_ERR_OUT_OF_RESOURCE If an internal malloc fails.
* @retval OPAL_ERR_NOT_FOUND If \em name is not found in \em env.
* @retval OPAL_SUCCESS If \em name is found and successfully deleted.
*
* If \em name is found in \em env, the string corresponding to
* that entry is freed and its entry is eliminated from the array.
*/
OPAL_DECLSPEC int opal_unsetenv(const char *name, char ***env) __opal_attribute_nonnull__(1);
/* A consistent way to retrieve the home and tmp directory on all supported
* platforms.
*/
OPAL_DECLSPEC const char* opal_home_directory( void );
OPAL_DECLSPEC const char* opal_tmp_directory( void );
/* Some care is needed with environ on OS X when dealing with shared
libraries. Handle that care here... */
#ifdef HAVE__NSGETENVIRON
#define environ (*_NSGetEnviron())
#else
OPAL_DECLSPEC extern char **environ;
#endif
END_C_DECLS
#endif /* OPAL_ENVIRON */