1.$ OPEN INPUT_FILE AVERAGE.DAT $ READ_LOOP: $ READ/END_OF_FILE=ENDIT INPUT_FILE NUM . . . $ GOTO READ_LOOP $ ENDIT: $ CLOSE INPUT_FILE The OPEN command opens the file named AVERAGE.DAT as an input file and assigns it the logical name INPUT_FILE. The file is opened with read access because the /READ qualifier is present by default. The READ command reads a record from the logical file INPUT_FILE into the symbol named NUM. The procedure executes the lines between the labels READ_LOOP and ENDIT until the end of the file is reached. At the end of the file, the CLOSE command closes the file. 2.$ OPEN/WRITE/ERROR=OPEN_ERROR OUTPUT_FILE TEMP.OUT $ COUNT = 0 $ WRITE_LOOP: $ COUNT = COUNT + 1 $ IF COUNT .EQ. 11 THEN GOTO ENDIT $ WRITE OUTPUT_FILE "Count is ''COUNT'." . . . $ GOTO WRITE_LOOP $ ENDIT: $ CLOSE OUTPUT_FILE $ EXIT $ $ OPEN_ERROR: $ WRITE SYS$OUTPUT "Cannot open file TEMP.OUT" $ EXIT The OPEN command with the /WRITE qualifier creates the file TEMP.OUT and assigns it the logical name OUTPUT_FILE. TEMP.OUT is a sequential file. The /ERROR qualifier specifies that if any error occurs while opening the file, the command interpreter should transfer control to the line at the label OPEN_ERROR. The command procedure writes records to the file TEMP.OUT until the symbol COUNT equals 11. 3.$ OPEN/READ INPUT_FILE TRNTO::DKA0:[COST]INVENTORY.DAT $ READ_LOOP: $ READ/END_OF_FILE=ENDIT INPUT_FILE NUM $ FIRST_CHAR = F$EXTRACT(0,1,NUM) $ WRITE SYS$OUTPUT FIRST_CHAR $ GOTO READ_LOOP $ ENDIT: $ CLOSE INPUT_FILE This command procedure opens the file INVENTORY.DAT located at remote node TRNTO as an input file, and assigns it the logical name INPUT_FILE. The READ command reads a record from the logical file INPUT_FILE into the symbol named NUM. The next two commands extract the first character from the record and write the character to the SYS$OUTPUT device. These two steps occur for all records in the file until the procedure reaches the end-of-file (EOF). At this point, the CLOSE command closes the file and deassigns the logical name INPUT_FILE.