PERROR(3) BSD Programmer's Manual PERROR(3)
perror - write error messages to standard error
#include <stdio.h> void perror(const char *string);
The perror() function looks up the language-dependent error message string affiliated with an error number and writes it, followed by a new- line, to the standard error stream. If the argument string is not the NULL pointer and is not zero length, it is prepended to the message string and separated from it by a colon and a space (': '). Otherwise, only the error message string is printed. The contents of the error message string are the same as those returned by strerror() with argument errno.
intro(2), psignal(3), setlocale(3), strerror(3)
The perror() function conforms to ANSI X3.159-1989 ("ANSI C89"). MirBSD #10-current June 29, 1991 1