I$IO

The I$IO routine provides an interface to the file handler.
Note: This ACUCOBOL-GT library routine is available in this COBOL version. Any compatibility issues in this COBOL system are in the Compatibility Issues section at the end of the topic.

An operation code and some number of additional parameters (depending on the operation called) are passed to the routine. The return code is set automatically after the call. The external variable F-ERRNO is set according to any errors found. F-ERRNO may not be reset on entry to I$IO, and should be checked only if I$IO returns an error condition.

Usage

CALL "I$IO" 
    USING OP-CODE, parameters

Parameters

  • OP-CODE Numeric parameter

    Specifies the file handling routine to be performed. This table shows which operation corresponds to each operation code. The operations are detailed in the description below:

    Code Operation
    1 OPEN-FUNCTION
    2 CLOSE-FUNCTION
    3 MAKE-FUNCTION
    4 INFO-FUNCTION
    5 READ-FUNCTION
    6 NEXT-FUNCTION
    7 PREVIOUS-FUNCTION
    8 START-FUNCTION
    9 WRITE-FUNCTION
    10 REWRITE-FUNCTION
    11 DELETE-FUNCTION
    12 UNLOCK-FUNCTION
    13 REMOVE-FUNCTION
    14 SYNC-FUNCTION
    15 EXECUTE-FUNCTION
    16 BEGIN-FUNCTION
    17 COMMIT-FUNCTION
    18 ROLLBACK-FUNCTION
    19 RECOVER-FUNCTION
    21 IN-TRANSACTION-FUNCTION
  • parameters vary depending on the op-code chosen

    The remaining parameters vary depending on the operation selected. They provide information and hold results for the operations specified. All parameters are passed by reference. Parameters may be omitted from those operations that do not require them.

Description

All parameters passed to I$IO are passed by reference. This applies even to parameters that are integer values in the corresponding file handling routines. All numeric parameters should be passed to I$IO as SIGNED-SHORT values. The I$IO routine provides any necessary addressing conversions. Note that a parameter must be in the correct format for its type. Parameters that are PIC X must be terminated by a LOW-VALUES character.

Except for the MAKE function, I$IO will automatically terminate any PIC X parameters with a LOW-VALUES byte for you. Also, you do not have to specify SYNC for level 01 or level 77 parameters because they are automatically synchronized by ACUCOBOL-GT.

The file filesys.def is a COBOL COPY file that contains many useful definitions for use with I$IO. It contains definitions for the I$IO codes along with the F-ERRNO error values and many useful pre-declared variables that are of the proper type and usage.

The behavior of this routine is affected by the FILENAME_SPACES configuration variable. The value of FILENAME_SPACES determines whether spaces are allowed in a file name.

Note: The runtime configuration variable FILE_PREFIX is ignored by the I$IO routine.

Compatibility Issues

  • filesys.def is not supplied in this COBOL system.
  • The FILENAME_SPACES configuration variable is not supported in this COBOL system.