Error C
Contents |
C - Basic Syntax C - Data Types C - Variables C - Constants C - Storage Classes C - Operators C - Decision Making C print error c - Loops C - Functions C - Scope Rules C - Arrays
Error Co
C - Pointers C - Strings C - Structures C - Unions C - Bit Fields C - Typedef bus error c C - Input & Output C - File I/O C - Preprocessors C - Header Files C - Type Casting C - Error Handling C - Recursion C - Variable Arguments
Error C 0007 Faxmaker
C - Memory Management C - Command Line Arguments C Programming Resources C - Questions & Answers C - Quick Guide C - Useful Resources C - Discussion Selected Reading Developer's Best Practices Questions and Answers Effective Resume Writing HR Interview Questions Computer Glossary Who is Who C - Error Handling Advertisements Previous Page Next Page As such, C programming does not error c function provide direct support for error handling but being a system programming language, it provides you access at lower level in the form of return values. Most of the C or even Unix function calls return -1 or NULL in case of any error and set an error code errno. It is set as a global variable and indicates an error occurred during any function call. You can find various error codes defined in
known as exception handling). By convention, the programmer is expected to prevent errors from occurring in the first place, and test return values from functions. For
Error C Stack Usage
example, -1 and NULL are used in several functions such as socket()
Error C Preprocessor /lib/cpp Fails Sanity Check
(Unix socket programming) or malloc() respectively to indicate problems that the programmer should be aware about. In a error c interpreter run time error worst case scenario where there is an unavoidable error and no way to recover from it, a C programmer usually tries to log the error and "gracefully" terminate the program. https://www.tutorialspoint.com/cprogramming/c_error_handling.htm There is an external variable called "errno", accessible by the programs after including
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 http://stackoverflow.com/questions/291828/what-is-the-best-way-to-return-an-error-from-a-function-when-im-already-returni about Stack Overflow the company Business Learn more about hiring developers or posting ads http://www.cprogramming.com/reference/preprocessor/error.html 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 What is the best way to return an error from a function error c when I'm already returning a value? up vote 12 down vote favorite 6 I wrote a function in C that converts a string to an integer and returns the integer. When I call the function I also want it to let me know if the string is not a valid number. In the past I returned -1 when this error occurred, because I didn't need to convert strings to print error c negative numbers. But now I want it to convert strings to negative numbers, so what is the best way to report the error? In case I wasn't clear about this: I don't want this function to report the error to the user, I want it to report the error to the code that called the function. ("Report" might be the wrong word to use...) Here's the code: s32 intval(const char *string) { bool negative = false; u32 current_char = 0; if (string[0] == '-') { negative = true; current_char = 1; } s32 num = 0; while (string[current_char]) { if (string[current_char] < '0' || string[current_char] > '9') { // Return an error here.. but how? } num *= 10; num += string[current_char] - '0'; current_char++; } if (negative) { num = -num; } return num; } c return share|improve this question asked Nov 15 '08 at 0:04 Jeremy Ruten 93.5k26134172 Heh. No multiple-value-bind in C :) –Svante Nov 15 '08 at 0:44 add a comment| 7 Answers 7 active oldest votes up vote 21 down vote There are several ways. All have their pluses and minuses. Have the function return an error code and pass in a pointer to a location to return
Practice Problems Quizzes Resources Source Code Source Code Snippets C and C++ Tips Finding a Job References Function Reference Syntax Reference Programming FAQ Getting Help Message Board Email About Us #error #error "This code should not compile" The #error macro allows you to make compilation fail and issue a statement that will appear in the list of compilation errors. It is most useful when combined with #if/#elif/#else to fail compilation if some condition is not true. For example: #ifndef __unix__ // __unix__ is typically defined when targetting Unix #error "Only Unix is supported" #endif Related C preprocessor tutorial Want to become a C++ programmer? The Cprogramming.com ebook, Jumping into C++, will walk you through it, step-by-step. Get Jumping into C++ today! Popular pages Exactly how to get started with C++ (or C) today C Tutorial C++ Tutorial 5 ways you can learn to program faster The 5 Most Common Problems New Programmers Face How to set up a compiler 8 Common programming Mistakes What is C++11? How to make a game in 48 hours Recent additions How to create a shared library on Linux with GCC - December 30, 2011 Enum classes and nullptr in C++11 - November 27, 2011 Learn about The Hash Table - November 20, 2011 Rvalue References and Move Semantics in C++11 - November 13, 2011 C and C++ for Java Programmers - November 5, 2011 A Gentle Introduction to C++ IO Streams - October 10, 2011 Custom Search Advertising | Privacy policy | Copyright © 1997-2011 Cprogramming.com. All rights reserved. | webmaster@cprogramming.com Popular pages C Tutorial Exactly how to get started with C++ (or C) today 5 ways you can learn to program faster C++ Tutorial The 5 Most Common Problems New Programmers Face How to make a game in 48 hours 8 Common Programming Mistakes What is C++11? Image credits