Reading CA FAVER Format Files › Assembler Example › GVOPEN

GVOPEN

The following returns each cluster name:

OPEN      XC    NAME,NAME         Request next cluster on tape
          CALL  GVOPEN,(NAME)     Call open/Locate entry point
          C     R15,=F'16'        Test return code
          BE    ERROR             Unable to open FVRFILE
          C     R15,=F'18'        End of File?
          BE    NOTFND            Cluster not found
          CLC   NAME,SRCNAME      Is this the cluster?
          BNE   OPEN              No, try the next one

NAME      DS    CL44              Hex zeros before call,
*                                 name on return
SRCNAME   DC    CL44'my.test.data.set'

The following locates a specific cluster:

       CALL  GVOPEN,(NAME)  Call open/Locate entry point
       LTR   R15,R15          Test return code
       BNZ   ERROR            Cluster not found or open error

NAME   DC    CL44'clustername'     Desired cluster

The following reads a cluster name from a file:

Add to JCL:

//NAME DD *
   clustername
/*

       CALL  GVOPEN,(NAME)  Call open/Locate entry point
       LTR   R15,R15        Test return code
       BNZ   ERROR          Error encountered

 NAME  DC    CL44'DDNAME=NAME'