Synopsis

Use valid format strings.

Enabled by default

Yes

Severity/Certainty

High/Low

Full description

The formatted output functions (fprintf() and related functions) convert, format, and print their arguments under control of a format string. The C standard outlines what format specifiers are valid in a format string. This check will find cases where the number of arguments to a format string function is invalid.

Coding standards

Code examples

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

#include <stdio.h>

void example(int a) {
  printf("%*d", a);
}

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

#include <stdio.h>

void example(int a) {
  printf("%*d", 5, a);
}