base/posix/safe_strerror.h

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