Check whether a data set exists

With ZOAU, you can check whether the data set ${prefix}.MY.JCL exists with any of the following ways:

• Issuing a shell command:

  If the data set exists, the return code is zero. If the data set does not exist, the return code is non-zero.

  • Option 1:

   dls "${prefix}.MY.JCL" 2>/dev/null >/dev/null
  

  • Option 2:

  mvscmdauth --pgm=IDCAMS --sysprint=dummy --sysin=stdin <<zz
    LISTCAT ENTRIES('${prefix}.MY.JCL')
  zz
  

• Calling an API in Python programs:

  datasets.exists("%s.MY.JCL" % HLQ)
  

To achieve the same purpose without ZOAU, you could write the following JCL:

//*
//* Check if dataset @@HLQ@@.ZOASAMP.MY.JCL exists
//* If it does, return code from step will be 0.
//* Otherwise it will be non-zero.
//*
//DSEXIST EXEC PGM=IDCAMS
//SYSPRINT DD DUMMY
//SYSIN DD *
  LISTCAT ENTRIES('@@HLQ@@.ZOASAMP.MY.JCL')
/*