Defined in header
void perror( const char *s );
Prints to stderr the contents of the null-terminated character string pointed to by
s is a null pointer), followed by the two characters ": ", followed by the implementation-defined error message describing the error code currently stored in the system variable errno (identical to the output of strerror(errno)), followed by '\n'.
|s||-||pointer to a null-terminated string with explanatory message|
open(): No such file or directory
| returns a text version of a given error code |
C++ documentation for perror