assert() in C

2. abort() in C

The C assert() function is a macro defined inside the <assert.h> header file. It is a function-like macro that is used for debugging. It takes an expression as a parameter,

If the expression evaluates to 1 (true), the program continue to execute.
If the expression evaluates to 0 (false), then the expression, source code filename, and line number are sent to the standard error, and then the abort() function is called.

Syntax of assert() in C

void assert(expression);

Parameters

expression: It is the condition we want to evaluate.

Return Value

The assert() function does not return any value.

If the identifier NDEBUG (“no debug”) is defined with #define NDEBUG then the macro assert does nothing. Common error output is in the form: Assertion failed: expression, file filename, line line-number.

Example: C Program to Illustrate the assert() Function

C

// C Program to demonstrate the use of assert() function
#include <assert.h>
#include <stdio.h>
 
void open_record(char* record_name)
{
    assert(record_name != NULL);
    /* Rest of code */
}
 
int main(void) { open_record(NULL); }

Output

test.c:7: open_record: Assertion `record_name != ((void *)0)' failed.
timeout: the monitored command dumped core
/bin/bash: line 1:    34 Aborted

C exit(), abort() and assert() Functions

The C exit(), abort(), and assert() functions are all used to terminate a C program but each of them works differently from the other. In this article, we will learn about exit, abort, and assert functions and their use in C programming language.

Tags:

#C-Functions #C Language