Synopsis

Detect and handle standard library errors.

Enabled by default

Yes

Severity/Certainty

High/High

Full description

The majority of the standard library functions, including I/O functions and memory allocation functions, return either a valid value or a value of the correct return type that indicates an error (for example, -1 or a null pointer). It is essential that programs detect and appropriately handle all errors in accordance with an error-handling policy. This check warns on usage of standard library functions listed in EX1 without checking for errors or explicitly discard the return value.

Coding standards

Code examples

The following code example fails the check and will give a warning:

#include<stdio.h>

void example(void) {
    printf("Hello, world\n");
}

The following code example passes the check and will not give a warning about this issue:

#include<stdio.h>

void example(void) {
    (void) printf("Hello, world\n"); // printf() return value safely ignored
}