Examples: HFS

Use these hierarchical file system examples to help you program your optical file system.

This topic demonstrates how the HFS API can be used with the ILE RPG programming language.

The programming examples demonstrate the following functions:

Retrieving a path name from an array
Calling the HFS API to open a stream file
Calling the HFS API to write a 256-byte buffer passed to the program as a parameter
Calling the HFS API to close the stream file

For more information about APIs, see Application device programming (APIs).

Note: By using the following code examples, you agree to the terms of the Code license and disclaimer information.

Getting a path and calling subroutines

This sample gets a path and calls subroutines.

E                      AR     1   5 36
C        *ENTRY        PLIST
* 2 PARAMETERS - A DATA BUFFER ID AND AN INDEX TO THE ARRAY
C                PARM           DATAIN    256 
C                	PARM           IDX        10 
* MOVE THE ARRAY ELEMENT TO A FIELD CALLED "PATH" 
C                	MOVE AR,IDX    PATH 
* EXECUTE SUBROUTINES TO OPEN, WRITE AND CLOSE A FILE 
C                	EXSR OPNSF 
C  		RTCD      	IFEQ 0 
C              		EXSR WRTSF 
C                 EXSR CLOSF 
C                 END 
C                 SETON                     LR   
* TABLE/ARRAY . . . . . . . :   AR 
** /QOPT/MYVOL1/DIRA/FILE
/QOPT/MYVOL1/DIRA/SUBDIRB/FILE
/QOPT/MYVOL1/DIRA/SUBDIRB/C/FILE
/QOPT/MYVOL1/DIRA/SUBDIRB/C/D/FILE 
/QOPT/MYVOL1/DIRA/SUBDIRB/C/D/E/FILE

Defining data structures for opening files

This sample defines data structures in the HFS.

* PATH LENGTH PARAMETER 
IPATHLN     DS 
I                                B   1    40PATHL 
* OPEN INFORMATION PARAMETER 
IOPNINF     DS 
I                               	1   1 EXISTS 
I                               	2   2 NOTTHR 
I                               	3   3 SYNASY 
I                               	4   4 RSV1 
I                       		      	5   5 SHAREM 
I                               	6   6 ACCESS 
I                                	7   7 OTYPE 
I                               	8  10 RSV3 
* ATTRIBUTE LENGTH PARAMETER 
IATTRLN    DS 
I                                B   1    40ATTRL 
* RETURN CODE PARAMETER
IRETCD      DS 
I                              		B   1    40RCLEN 
I                              		B   5     80RTCD 
I                          	   	9   15    CONDTN 
I                               	16  16       RSV
I                                	17  272      MSG 
* BYTES TO READ/WRITE PARAMETER
IBYTRDW       DS                 	B   1   40BYT2RW   
* BYTES ACTUALLY READ/WRITTEN PARAMETER
IBYTACT       DS                 B   1   40BYTARW

Opening an optical file

This sample opens an optical file.

* PARAMETER LIST FOR QHFOPNSF CALL 
C           POPNSF    PLIST 
C                    	PARM            	FHDLE  16 
C                     PARM          		PATH   36 
C                     PARM            	PATHL 
C                    	PARM            	OPNINF 
C                     PARM            	ATRTBL  1
C                     PARM            	ATTRLN 
C                     PARM           		ACTION  1 
C                     PARM            	RETCD   
C* OPEN FILE SUBROUTINE 
C           OPNSF     BEGSR 
C* FILL IN THE PATH AND ATTRIBUTE LENGTHS
C                  		Z-ADD36         PATHL  SET PATH LEN=36 
C                    	Z-ADD*ZEROS     ATTRL  ZERO ATTRIBUTE LENGTH 
C* FILL IN THE OPNINF PARAMETER 
C                     MOVE '0'        EXISTS   1   FAIL IF EXISTS
C                     MOVE '1'        NOTTHR   1  CREATE IF NOT THERE 
C                     MOVE '0'       	SYNASY   1  ASYNCHRONOUS 
C                     MOVE *BLANKS   	RSV1     1 
C                    	MOVE '1'       	SHAREM   1  DENY NONE 
C                 	  MOVE '2'       	ACCESS   1  READ/WRITE 
C                     MOVE '0'      	OTYPE    1  NORMAL 
C                     MOVE *BLANKS    RSV3    	3 
C* CALL THE API TO OPEN THE STREAM FILE 
C                     CALL 'QHFOPNSF'POPNSF        50 
C           OPNEND    ENDSR

Writing a file to an optical disk

This sample writes a file to an optical disk.

* PARAMETER LIST FOR QHFRDSF OR QHFWRTSF CALL 
C           PRWSF     PLIST
C                     PARM          FHDLE   16 
C                     PARM          DATAIN 
C                     PARM          BYT2RW 
C                    	PARM          BYTARW 
C                     PARM          RETCD
C* CALL API TO WRITE TO THE FILE 
C           WRTSF     BEGSR 
C                    Z-ADD256       BYT2RW SET WRITE LENGTH=256 
C                    CALL 'QHFWRTSF'PRWSF          50 
C           WRTEND    ENDSR

Closing an optical file

This sample closes an optical file.

* PARAMETER LIST FOR QHFCLOSF CALL 
C           PCLOSF    PLIST 
C                 PARM           	FHDLE   16 
C                 PARM         		RETCD   
C* CALL API TO CLOSE THE FILE 
C           CLOSF     BEGSR 
C           CALL 'QHFCLOSF'PCLOSF         50 
C           CLSEND    ENDSR
C* END OF SAMPLE RPG CALL TO THE HFS API