/*** *wperror.c - print system error message (wchar_t version) * * Copyright (c) Microsoft Corporation. All rights reserved. * *Purpose: * defines _wperror() - print wide system error message * System error message are indexed by errno. * *******************************************************************************/ #include #include #include #include #include #include #include /*** *void _wperror(wmessage) - print system error message * *Purpose: * prints user's error message, then follows it with ": ", then the system * error message, then a newline. All output goes to stderr. If user's * message is nullptr or a null string, only the system error message is * printer. If errno is weird, prints "Unknown error". * *Entry: * const wchar_t *wmessage - users message to prefix system error message * *Exit: * Prints message; no return value. * *Exceptions: * *******************************************************************************/ extern "C" void __cdecl _wperror(wchar_t const* const wide_user_prefix) { // If the user did not provide a prefix, we can just call perror: if (wide_user_prefix == nullptr || wide_user_prefix[0] == L'\0') return perror(nullptr); // Otherwise, we need to convert the prefix into a narrow string then pass // it to perror: size_t required_count = 0; _ERRCHECK_EINVAL_ERANGE(wcstombs_s(&required_count, nullptr, 0, wide_user_prefix, INT_MAX)); if (required_count == 0) return; __crt_unique_heap_ptr const narrow_user_prefix(_calloc_crt_t(char, required_count)); if (narrow_user_prefix.get() == nullptr) return; errno_t const conversion_result = _ERRCHECK_EINVAL_ERANGE(wcstombs_s( nullptr, narrow_user_prefix.get(), required_count, wide_user_prefix, _TRUNCATE)); if (conversion_result != 0) return; return perror(narrow_user_prefix.get()); }