Assembler example with CMDX control block, multi-line WTO

This is an example of a multiple-line WTO using CONNECT. The text is variable. This code is re-entrant, if the static data has been copied into a getmained area.

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* Access to CMDX parameter list
       L       R8,0(R1)           save address of CMDX
       USING   CMDX,R8            Access the CMDX
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* Put the first line of text into the TEXT field
* Set the length of the first line
         LA    R4,L'first line of text
         STH   R4,TEXTLEN
* Copy actual first line into text field
         MVC   TEXTTEXT(L'first line of text),first line of text
* Clear register 0 so it will not look like a CONNECT ID
         XR    R0,R0
* Issue WTO for the first line
         WTO   TEXT=((TEXTADDR,,)),                                    X
               CONSID=CMDXC4ID,                                        X
               CART=CMDXCART,                                          X
               DESC=5,                                                 X
               MF=(E,LINE1)
* Save the connect ID returned from the first line WTO
         ST    R1,MSGID
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* Repeat the following block until finished putting out all the lines
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* Put the next line of text into the TEXT field
* Set the length of the next line
         LA    R4,L'next line of text
         STH   R4,TEXTLEN
* Copy actual next line into text field
         MVC   TEXTTEXT(L'next line of text),next line of text
         WTO   TEXT=((TEXTADDR,,)),                                    X
               CONNECT=MSGID,                                          X
               MF=(E,CONTINUE)
*
* Ship a "null end line" (no text) to indicate message is finished
         WTO   ('',E),                                                 X
               CONNECT=MSGID,                                          X
               MF=(E,NULLEND)
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* Dynamic variables - declare as static and copy into getmained area
LINE1     WTO  TEXT=((,D)),                                            X
               CONSID=,                                                X
               CART=,                                                  X
               DESC=5,                                                 X
               MF=L
CONTINUE  WTO  TEXT=((,D)),                                            X
               CONNECT=,                                               X
               MF=L
NULLEND   WTO  ('',E),                                                 X
               CONNECT=,                                               X
               MF=L
TEXTADDR DS 0H
TEXTLEN  DC CL2' '
TEXTTEXT DC CL72' '
MSGID    DS F
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* DSECTs
* CMDX - Command exit parameter list                                -*
        IEZVX101                  CMDX