Summary

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	File:     ispf.icn

	Subject:  Procedures to communicate between Icon and ISPF

	Author:   Alan Beale

	Date:     August 14, 1996

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   This file is in the public domain.

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  The functions ispqry, ispexec, ispcopy and isprepl must be installed
  in the extcall module of iconx for these procedures to do anything useful.

     These procedures provide an interface between Icon and ISPF:

     ISPQry()        returns &null if ISPF services are available, or
                     fails if not

     ISPExec(cmd)    Sends an ISPEXEC command to ISPF.  Returns the
                     ISPF return code if less than 12.  Otherwise,
                     causes run-time error 500, and prints an error
                     message if errors are not trapped.  If errors
                     are trapped, the message is in &errorvalue.

     ISPVcopy(var)   Returns the value of a variable in the ISPF
                     "function pool", or fails if the named variable
                     is not defined.  ISPF errors are handled as by
                     ISPExec.

     ISPVrepl(var,val) Stores a new value in an ISPF variable (or
                     creates the variable if it does not exist).
                     Returns 0 if successful.  ISPF errors are handled
                     as by ISPExec.

 The first time ISPF is called, CONTROL ERRORS RETURN is established.
 This can be overridden if desired by a call to ISPExec for that
 purpose.

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  Requires:  CMS of MVS

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This file is part of the (main) package.

ISPExec(cmd)

 transmit an ISPEXEC request to ISPF

ISPQry()

 detect presence or absence of ISPF

ISPVcopy(var)

 get value of an ISPF "function" variable

ISPVrepl(var, value)

 assign to an ISPF variable