perror.c

Version 6 Unix 核心源代码 Version 6 Unix 核心源代码

/*
 * Print the error indicated
 * in the cerror cell.
 */

int	errno;
int	sys_nerr;
char	*sys_errlist[];
perror(s)
char *s;
{
	register char *c;
	register n;

	c = "Unknown error";
	if(errno < sys_nerr)
		c = sys_errlist[errno];
	n = strlen(s);
	if(n) {
		write(2, s, n);
		write(2, ": ", 2);
	}
	write(2, c, strlen(c));
	write(2, "\n", 1);
}

/*
 * Return the number of bytes in a string
 */

strlen(str)
char *str;
{
	register char *s;

	s = str;
	while(*s++)
		;
	return(s-str-1);
}