Akatsukami wrote:... Or. more likely, Pearl-chan lives under a bridge and eats billy goats.
And doesn't realize he has run into Billy Goat Gruffs!
Another, "real world" example. This is a modification of a program that calls IDCAMS and uses the SYSIN exit to pass a LISTCAT LEVEL(xxx) command to IDCAMS, and uses the SYSPRINT exit to examine the output. The modification calls IDCAMS twice. The first call issues a LISTCAT ENTRIES(xxx), and uses a dummy SYSPRINT exit since all the program cares about is the return code. The second call is basically the original call, but it only executes if the first call returned with RC = 0. The first update group is the two calls, with modified setup. The second group is the update to the dynamic SYSIN exit to return the proper command to IDCAMS. The third group is the SYSPRINT IDCAMS exit to toss IDCAMS's SYSPRINT output into the bit bucket. The fourth group is the new parameter lists. The last group is the skeleton for the new IDCAMS command.
./ NUMBER INSERT=YES,SEQ1=20400000,NEW1=20410000,INCR=10000
MVC AUSERID,UUSER-USER(3) COPY USERID TO LISTCAT ENT CMD
MVI IXSTAT,0 INDICATE LISTCAT ENT
LINK SF=(E,LINKIDCAMS),MF=(E,IDCPARMD) CALL IDCAMS
LTR 15,15 TEST RC
JNZ SKIPIDCAMS BR IF NO ALIAS POINTER
MVI IXSTAT,1 INVOKE LISTCAT LEVEL
./ DELETE SEQ1=20600000,SEQ2=20600200
./ NUMBER INSERT=YES,SEQ1=50000000,NEW1=50200000,INCR=100000
LHI 15,4 SET EOF RETURN CODE
L 14,8(,1) LOAD ADDR OF I/O BUFFER WORDS
CLI IXSTAT,X'FF' TEST IF RETURN EOF
JE IDCR0200 BR IF SO
LA 1,=A(ACARD,L'ACARD) LOAD LENGTH AND ADDRESS OF THE
* LISTCAT ENTRIES(XXX) COMMAND
CLI IXSTAT,0 TEST IF LISTCAT ENTRIES(XXX) COMMAND
JE *+L'*+4 BR IF SO
LA 1,=A(IXCARD,L'IXCARD) LOAD LENGTH AND ADDRESS OF THE
* LISTCAT LEVEL(XXXX) COMMAND
MVI IXSTAT,X'FF' RESET IXSTAT
MVC 0(8,14),0(1) SAVE ADDRESS & LENGTH FOR IDCAMS
SR 15,15 SET RC = 0
./ DELETE SEQ1=50200000,SEQ2=52000000
./ NUMBER INSERT=YES,SEQ1=62200000,NEW1=62210000,INCR=10000
IDCDUMMYW SR 15,15
./ NUMBER INSERT=YES,SEQ1=66200000,NEW1=66210000,INCR=10000
IDCPARMD CALL ,(IDCNULL,IDCNULL,IDCNULL,IDCIOD),VL,MF=L IDCAMS PARMS
IDCIOD DC A(2) IDCAMS I/O EXIT PARMS
DC A(IDCDD1,IDCREAD,MAINPGM) SYSIN
DC A(IDCDD2,IDCDUMMYW,MAINPGM) SYSPRINT
./ NUMBER INSERT=YES,SEQ1=74000000,NEW1=74010000,INCR=10000
ACARD DC 0C' LISTCAT ENTRIES(XXXXXXXX)',C' LISTCAT ENTRIES('
AUSERID DC CL8' ',C')'
In the first version of the update there was a very confusing bug: IDCAMS got an S0C1 in a fairly strange location. After some analysis comparing the before and after versions of the program I realized the exit was missing the L 14,8(,1) instruction; I think reg 14 still pointed to IDCAMS when it did the MVC 0(8,14),0(1) instruction. After the L 14 instruction was added to the exit it appeared to work perfectly. This is still a work in progress, though, so there may be more problems since the initial test was a just a point test. There are two changes from the true update to what is here. Where you see MAINPGM the actual code uses the true name of the program CSECT. The second change removed a couple of continuation markers where a comment extended to a second line, and the second line was changed to a comment so the code box would display the update better. These are the kind of changes the TS could make in his problem. Actually, since the TS couldn't get the Billy Goats to respond to the request, I suspect the TS has abandoned this topic.
Twenty five years ago when I was reading stories to my son, this fable - probably adapted from a Grim brothers fairy tale - was one of our favorites.