1 // Copyright (c) 2011 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_POSIX_SAFE_STRERROR_H_
6 #define BASE_POSIX_SAFE_STRERROR_H_
7 
8 #include <stddef.h>
9 
10 #include <string>
11 
12 #include "base/base_export.h"
13 
14 namespace base {
15 
16 // BEFORE using anything from this file, first look at PLOG and friends in
17 // logging.h and use them instead if applicable.
18 //
19 // This file declares safe, portable alternatives to the POSIX strerror()
20 // function. strerror() is inherently unsafe in multi-threaded apps and should
21 // never be used. Doing so can cause crashes. Additionally, the thread-safe
22 // alternative strerror_r varies in semantics across platforms. Use these
23 // functions instead.
24 
25 // Thread-safe strerror function with dependable semantics that never fails.
26 // It will write the string form of error "err" to buffer buf of length len.
27 // If there is an error calling the OS's strerror_r() function then a message to
28 // that effect will be printed into buf, truncating if necessary. The final
29 // result is always null-terminated. The value of errno is never changed.
30 //
31 // Use this instead of strerror_r().
32 BASE_EXPORT void safe_strerror_r(int err, char *buf, size_t len);
33 
34 // Calls safe_strerror_r with a buffer of suitable size and returns the result
35 // in a C++ string.
36 //
37 // Use this instead of strerror(). Note though that safe_strerror_r will be
38 // more robust in the case of heap corruption errors, since it doesn't need to
39 // allocate a string.
40 BASE_EXPORT std::string safe_strerror(int err);
41 
42 }  // namespace base
43 
44 #endif  // BASE_POSIX_SAFE_STRERROR_H_
45