l5.1a

<B>Digital的Unix操作系统VAX 4.2源码</B>

#print
(Section 1.5)
Write a program that copies exactly three characters
from its input to its output.
When compiled and tested, type ready.
#once #create Ref
XY
#once #create z1
XY
marks the spot.
#user
a.out <z1 >z2
#cmp z2 Ref
#succeed
/* Here is one possible solution */

main()
{
	putchar(getchar());
	putchar(getchar());
	putchar(getchar());
}
#log
#next
5.1b 10
5.2a 5