WRITE A PROGRAM DISPLAY FILE CONTENTS IF FILE EXISTING

 1.

VI SP29

X=0

WHILE TEST $X=0

DO

ECHO''ENTER A FILE NAME:\C''

READ FNAME

IF TEST!-F$FNAME

THEN

ECHO''$FNAME IS NOT FOUND..........''

CONTINUE

ELSE

BREAK

FI

DONE

CAT $FNAME|MORE

:WQ(SAVE AND QUIT)

THE UNIT LOOP:

SYNTAX:

UNTIL[CONDITION]

DO

.........................

........................

DONE

THE STATEMENT WITHIN THE UNTIL LOOP KEEP ON GETTING EXECUTED TILL THE CONDITION IS FALSE.WHEN THE CONDITION IS TRUE THE CONTROL TRANSFER TO AFTER DONE STATEMENT.