R$IO

The R$IO routine provides a low-level interface to relative files allowing them to be managed without knowing their FD.

The routine is not affected by iscobol.file.prefix and iscobol.file.suffix configuration properties.

Syntax:

CALL "R$IO" USING opCode                     parameters             GIVING returnCode

Parameters:

opCode	Specifies the file handling function to be performed.   Valid values, defined in isfilesys.def are:
	R-OPEN-FUNCTION	Opens an existing file
	R-CLOSE-FUNCTION	Closes an opened file
	R-MAKE-FUNCTION	Creates an empty file
	R-READ-FUNCTION	Reads a record from a file
	R-NEXT-FUNCTION	Reads the next record in a file
	R-PREVIOUS-FUNCTION	Reads the previous record in a file
	R-START-FUNCTION	Sets the file pointer on a specific record
	R-WRITE-FUNCTION	Writes data into file
	R-REWRITE-FUNCTION	Rewrites data into file
	R-DELETE-FUNCTION	Deletes data from file
	R-UNLOCK-FUNCTION	Unlocks all locked records in a file
parameters	Parameters depend on the opcode.

Return code:

returnCode contains useful information such as file handles and record sizes or zero if an error occurs. Check the external variable F_ERRNO for additional information on the error.

Examples:

Example - Create a relative file, write and read records from it

working-storage section.  copy "isfilesys.def".    77  f                       handle .  77  file-io                 pic x(128).  77  rec-buffer              pic x(22).    01  rio-lparms.      03 max-rec-sz           pic 999.      03 filler               pic x value ",".      03 min-rec-sz           pic 999.    77  key-val                 pic 9(5) value 0.    procedure division.  main.  *> creates the file  *> this is the FD  *>  01 record.  *>   03 r-key    pic 99.  *>   03 r-data   pic x(20).      display "Creating file..."      move "c:\tmp\myrelfile" to file-io    move 22 to max-rec-sz, min-rec-sz    set r-make-function to true                          call "r$io" using rio-function, file-io, rio-lparms                   if return-code = 0       display message "R$IO Error: make : " F_ERRNO     end-if                 *> opening     display "Opening file..."                set r-open-function to true    move fio to open-mode    move 22  to max-rec-size, min-rec-size    call "r$io" using rio-function, file-io, open-mode                       max-rec-size, min-rec-size    if return-code > 0       move return-code to f    else       display message "R$IO Error: open : " F_ERRNO     end-if

*> record writing    move 0 to key-val.    display "Writing into file..."      set r-write-function to true    perform 3 times       add 1 to key-val       move "00xxx" to rec-buffer            call "r$io" using rio-function, f, rec-buffer,                                  max-rec-size, key-val       if return-code = 0          display message "R$IO Error: write : " F_ERRNO        end-if    end-perform      *> start    display "Getting the first record..."     set r-start-function to true    set f-equals       to true    move 1             to key-val    call "r$io" using rio-function, f, key-val, start-mode    if return-code = 0       display message "R$IO Error: start : " F_ERRNO     end-if      *> read next    display "Reading next record..."    set r-next-function to true    call "r$io" using rio-function, f, rec-buffer     if return-code = 0       display message "R$IO Error: next : " F_ERRNO     end-if      *> close    display "Closing file..."    set r-close-function to true    call "r$io" using rio-function, f      goback.