Synopsis

The return value of a const standard library function is not used.

Enabled by default

Yes

Severity/Certainty

Low/Medium

Full description

The return value of a const standard library function is not used. Because this function is defined as const, the call itself has no side effects; the only yield is the return value. If this return value is not used, the function call is redundant. These functions are inspected: memchr(), strchr(), strpbrk(), strrchr(), strstr(), strtok(), gmtime(), getenv(), and bsearch(). Discarding the return values of these functions is harmless but might indicate a misunderstanding of the application logic or purpose.

Coding standards

Code examples

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

#include <string.h>

void example(void) {
  strchr("Hello", 'h');  // No effect
}

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

#include <string.h>

void example(void) {
  char* c = strchr("Hello", 'h');  //OK
}