1// Copyright (c) 2009 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef BASE_SAFE_STRERROR_POSIX_H_
6#define BASE_SAFE_STRERROR_POSIX_H_
7#pragma once
8
9#include <string>
10
11// BEFORE using anything from this file, first look at PLOG and friends in
12// logging.h and use them instead if applicable.
13//
14// This file declares safe, portable alternatives to the POSIX strerror()
15// function. strerror() is inherently unsafe in multi-threaded apps and should
16// never be used. Doing so can cause crashes. Additionally, the thread-safe
17// alternative strerror_r varies in semantics across platforms. Use these
18// functions instead.
19
20// Thread-safe strerror function with dependable semantics that never fails.
21// It will write the string form of error "err" to buffer buf of length len.
22// If there is an error calling the OS's strerror_r() function then a message to
23// that effect will be printed into buf, truncating if necessary. The final
24// result is always null-terminated. The value of errno is never changed.
25//
26// Use this instead of strerror_r().
27void safe_strerror_r(int err, char *buf, size_t len);
28
29// Calls safe_strerror_r with a buffer of suitable size and returns the result
30// in a C++ string.
31//
32// Use this instead of strerror(). Note though that safe_strerror_r will be
33// more robust in the case of heap corruption errors, since it doesn't need to
34// allocate a string.
35std::string safe_strerror(int err);
36
37#endif  // BASE_SAFE_STRERROR_POSIX_H_
38