The abort function is a function in the C standard library that causes abnormal program termination. The abort function does not return control to the calling program and does not perform any cleanup operations, such as calling functions registered with the atexit function.

The syntax of the abort function is as follows:

void abort(void);

The abort function does not take any arguments. When it is called, the program is terminated and any open files are not closed, any memory allocated by the program is not deallocated, and any other cleanup operations are not performed.

The abort function is typically used when an unrecoverable error occurs, and the program cannot continue to run. For example, if a program encounters a critical error that prevents it from functioning properly, the program can call the abort function to terminate itself.

Here is an example that demonstrates how to use the abort function:

#include <stdlib.h>

int main(void) {
    int *ptr = (int *)malloc(10 * sizeof(int));
    if (ptr == NULL) {
        abort();
    }
    /* rest of the program */
    return 0;
}

In this example, the program calls the malloc function to allocate memory for an array of 10 int elements. If the malloc function is unable to allocate the requested memory, it returns a null pointer. In this case, the program calls the abort function to terminate itself. If the malloc function is successful, the program continues to execute normally.