/*
 * Sample program for read() and write() system call - No. 3 and No.4
 *
 * read(2) - read from a file descriptor
 *
 * #include <unistd.h>
 *
 * ssize_t read(int fd, void *buf, size_t count);
 *
 * write(2) - write to a file descriptor
 *
 * #include <unistd.h>
 *
 * ssize_t write(int fd, const void *buf, size_t count);
 */

#include <stdio.h>

/* file descriptor --- from <unistd.h> */

#define STDIN_FILENO    0       /* Standard input.  */
#define STDOUT_FILENO   1       /* Standard output.  */
#define STDERR_FILENO   2       /* Standard error output.  */

main()
{
	int n;
	char buf[BUFSIZ];

	while((n = read(STDIN_FILENO, buf, sizeof buf)) > 0 ) {
		write(STDOUT_FILENO, buf, n);
	}

	exit(0);
}