12.7 REWIND Statement

The REWIND statement positions a sequential or direct access file at the beginning of the file (the initial point). It takes one of the following forms:

REWIND ([UNIT=]io-unit [, ERR=label] [, IOSTAT=i-var])
REWIND io-unit

io-unit
Is an external unit specifier.

label
Is the label of the branch target statement that receives control if an error occurs.

i-var
Is a scalar integer variable that is defined as a positive integer if an error occurs and zero if no error occurs.

Rules and Behavior

The unit number must refer to a file on disk or magnetic tape, and the file must be open for sequential, direct, or append access.

If a REWIND is done on a direct access file, the NEXTREC specifier is assigned a value of 1.

A REWIND statement must not be specified for a file that is open for keyed access.

If a file is already positioned at the initial point, a REWIND statement has no effect.

If a REWIND statement is specified for a unit that is not open, it has no effect.

Examples

The following statement repositions the file connected to I/O unit 3 to the beginning of the file:

  REWIND 3

  REWIND (UNIT=9, IOSTAT=IOS, ERR=10)

This statement positions the file connected to unit 9 at the beginning of the file. If an error occurs, control is transferred to the statement labeled 10, and a positive integer is stored in variable IOS.

For More Information:

• On the UNIT control specifier, see Section 10.2.1.1.
  
  
• On the ERR control specifier, see Section 10.2.1.8.
  
  
• On the IOSTAT control specifier, see Section 10.2.1.7.
  
  
• On record position, advancement, and transfer, see your user manual.