Positions file at its initial point.
Syntax
The syntax of the REWIND statement can take one of the following forms:
Long form:
REWIND (io-specifier-list) |
- integer-expression
is the unit connected to a sequential file or device.
- io-specifier-list
is a list of the following comma-separated I/O specifiers:
- [UNIT=]unit
specifies the
unit connected to an external file opened for sequential access.
unit must be an integer expression that evaluates to a
number greater than 0. If the optional keyword UNIT= is omitted, unit must be the first item in io-specifier-list.
- ERR=stmt-label
specifies the
label of the executable statement to which control passes if an error
occurs during statement execution.
- IOSTAT=integer-variable
returns the I/O
status after the statement executes. If the statement executes successfully, integer-variable is set to zero. If an error occurs, it is set to
a positive integer that indicates which error occurred.
Description
The REWIND statement repositions the file connected to the
specified unit at the start of the first record. If the file is
already at its starting point or if the unit is not connected to
a file, the REWIND statement has no effect.
Examples
The following example of the REWIND statement repositions the file connected to unit
10 to its initial point:
The next example repositions to its initial point the file
connected to unit 21. If an error occurs during the execution of
the statement, control passes to the statement at label 99, and
the error code is returned in ios:
REWIND (21, ERR=99, IOSTAT=ios) |
Related statements
BACKSPACE, ENDFILE, and OPEN
Related concepts
For information about I/O concepts, see Chapter 8 “I/O
and file handling”. This chapter also lists example programs
that use I/O.
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