Error Functions H
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of a library call. The functions strerror and perror give you the standard error message for a given error code; the variable program_invocation_short_name gives you convenient access to the name of the program that encountered error functions in index expression must be marked immutable the error. Function: char * strerror (int errnum) Preliminary: | MT-Unsafe race:strerror | AS-Unsafe error functions excel heap i18n | AC-Unsafe mem | See POSIX Safety Concepts. The strerror function maps the error code (see Checking for Errors) specified error function values by the errnum argument to a descriptive error message string. The return value is a pointer to this string. The value errnum normally comes from the variable errno. You should not modify the string returned by c error function strerror. Also, if you make subsequent calls to strerror, the string might be overwritten. (But it’s guaranteed that no library function ever calls strerror behind your back.) The function strerror is declared in string.h. Function: char * strerror_r (int errnum, char *buf, size_t n) Preliminary: | MT-Safe | AS-Unsafe i18n | AC-Unsafe | See POSIX Safety Concepts. The strerror_r function works like strerror but instead of returning the error message in a
Error.h C
statically allocated buffer shared by all threads in the process, it returns a private copy for the thread. This might be either some permanent global data or a message string in the user supplied buffer starting at buf with the length of n bytes. At most n characters are written (including the NUL byte) so it is up to the user to select a buffer large enough. This function should always be used in multi-threaded programs since there is no way to guarantee the string returned by strerror really belongs to the last call of the current thread. The function strerror_r is a GNU extension and it is declared in string.h. Function: void perror (const char *message) Preliminary: | MT-Safe race:stderr | AS-Unsafe corrupt i18n heap lock | AC-Unsafe corrupt lock mem fd | See POSIX Safety Concepts. This function prints an error message to the stream stderr; see Standard Streams. The orientation of stderr is not changed. If you call perror with a message that is either a null pointer or an empty string, perror just prints the error message corresponding to errno, adding a trailing newline. If you supply a non-null message argument, then perror prefixes its output with this string. It adds a colon and a space character to separate the m
the try, catch, and throw statements. The c_exception class lets you handle errors that are created by
C Err Function
the functions and operations in the complex class. When the Complex c error codes Mathematics Library detects an error in a complex operation or function, it invokes complex_error(). This friend c error handling best practices function of c_exception has a c_exception object as its argument. When the function is invoked, the c_exception object contains data members that define the function name, arguments, http://www.gnu.org/s/libc/manual/html_node/Error-Messages.html and return value of the function that caused the error, as well as the type of error that has occurred. The data members are: complex arg1; // First argument of the error-causing function complex arg2; // Second argument of the error-causing function char* name; // Name of the error-causing function complex retval; // Value returned http://publib.boulder.ibm.com/iseries/v5r1/ic2924/books/c0948110208.htm by default definition of complex_error int type; // The type of error that has occurred. If you do not define your own complex_error function, complex_error sets the complex return value and the errno error number. Defining a Customized complex_error Function You can either use the default version of complex_error() or define your own version of the function. If you define your own complex_error() function, and this function returns a nonzero value, no error message will be generated. Handling Errors Outside of the Complex Mathematics Library There are some cases where member functions of the Complex Mathematics Library call functions in the math library. These calls can cause underflow and overflow conditions that are handled by the matherr() function that is declared in the math.h header file. For example, the overflow conditions that are caused by the following calls are handled by matherr(): exp(complex(DBL_MAX, DBL_MAX)) pow(complex(DBL_MAX, DBL_MAX), INT_MAX) norm(complex(DBL_MAX, DBL_MAX)) DBL_MAX is the maximum valid double value, and is defined in flo
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Include error.Functions already declared up vote -1 down vote favorite I've read a lot for this problem ,but I haven't found a proper solution. So i have 4 files: includes.h - which contains all libraries I need in other files + some global functions cities.h - which contains declarations of 2 classes cities.cpp - which contains definitions of the 2 classes in cities.h source.cpp - where is the main functon And I have(and need) these includes //cities.h #include "includes.h" //cities.cpp #include "cities.h" //source.cpp #include "cities.h" I've tried almost all combinations of #ifndef in all of the files and the program continues to give me the same error: function_X already declared in cities.obj.And this error repeats for all functions in "includes.h". Please help me.This makes me a lot of headaches. c++ include header-files share|improve this question asked May 13 '13 at 21:17 dragonator 4719 Does includes.h #include cities.h? –Andy Prowl May 13 '13 at 21:18 Do any of the headers define (rather than declare) functions? –RichieHindle May 13 '13 at 21:19 if you have a function defined in cities.h add inline to stop multiple definitions error. Also show use the exact error, it will help use debug it faster. –andre May 13 '13 at 21:22 No,headers.h