Check IFS object existence

The need of objects that exist on the IFS increases daily, and along with those needs comes uncertain programmer...

headaches. Using CHKOBJ to determine the existence of an object is limited to HFS objects, and the ability to use that command on the IFS is non-existant. I happened to have read a similar tip where another programmer used an API to accomplish the task of determining whether an object existed on the IFS.

The excerpt below is a nice little program, which is limited to a 30 alpha string in this example, that uses the CHKIN and CHKOUT commands to determine the existence of an object. If the CHKOUT command is successful, then the object must be checked back in via the CHKIN to prevent object locks.

PGM        PARM(&STMF &CODE)                     
                                                        
DCL        VAR(&STMF) TYPE(*CHAR) LEN(30)               
     
DCL        VAR(&CODE) TYPE(*CHAR) LEN(1)                
                                                        
CHKOUT     OBJ(&STMF)                                   
MONMSG     MSGID(CPFA0A9) EXEC(CHGVAR VAR(&CODE) +      
             VALUE('0')) /* NOT FOUND */                
MONMSG     MSGID(CPF0000) EXEC(DO) /* ANY OTHER ERROR + 
             (IN USE) */                                
CHGVAR     VAR(&CODE) VALUE('1') /* IT ALREADY EXISTS */
CHKIN      OBJ(&STMF) /* RELEASE USE */                 
MONMSG     MSGID(CPF0000)                               
ENDDO                                                  
ENDPGM