std::perror

void perror( const char *s );

Prints a textual description of the error code currently stored in the system variable errno to stderr.

The description is formed by concatenating the following components:

• the contents of the null-terminated byte string pointed to by s (unless s is a null pointer)
• ": "
• implementation-defined error message describing the error code stored in errno. This message is identical to the output of std::strerror(errno).
• '\n'.

Parameters

Return value

(none).

Example

#include <cmath>
#include <cerrno>
#include <cstdio>
 
int main()
{
    double not_a_number = std::log(-1.0);
    if (errno == EDOM) {
        std::perror("log(-1) failed");
    }
}

log(-1) failed: Numerical argument out of domain

See also