April 1, 1981
r ,PROr;RAr.'f CSECT S\VRET PROGRAM,12 LR 12,15 ST 14,SAVFET L DS 14,SAVRET 15,0 14
FESTABLISH ADDRESSABILITY SAVE RETURN ADDRESS IN R14 LOAD RETURN ADDRESS SET RETURN CODE IN R15 GO SAVE AREA Figure Sample Assembler Proaram Entry and Exit Linkage RETURN CODE HANDLING Feqister 15, in addition to its role in entry linkage, is also used in CMS as return code reqister. All of the internal routines completion code by way of register 15, and the SVC routines that receive control when any proqram completes execution examine register 15.
If 15 contains a nonzero value, this value is placed in the ready messaqe, following the "R": hh:mm:ss
Whenyou are executinq proqrams in it is good practice, if your
proqrams do not use reqister 15 as a return code register, to place a
zero in it before transferrina control back toCMS. Jtherwise, the ready
messagemay display meaningless data.
WhenYOI execute a proqram from your terminal, CMS scan routine sets UP a oarameter list based on your command input line. The parameter list
is doubleword-aligned, with parameters occupying successive doublewords.
Thescan routine recoqnizes blanks and parentheses as argument
delimiters: parentheses are placed, in the parameter list, in separate
doublewords.
For example, if you have aCMS MODULE file named TESTPROG, and you
call it with the command line:
t es t prog (f i 1 e 2)
The scan routine sets up the parameter list:CMNDLIST DS DC DC DC DC DC OD CL8'TESTPROG' CL8' ('
CL8'FILE2'Ct8 ') , 8X'FF' The last doubleword is made up of all 1s, to act as a delimiter.
Ifyou enter any argument lonqer than eight characters,
truncated and only the first eight characters appear in the
However, no error condition results.240 IBM VM/370 eMS User's Guide
it is
list.
r ,
F
If
When
proqrams do not use reqister 15 as a return code register, to place a
zero in it before transferrina control back to
message
When
is doubleword-aligned, with parameters occupying successive doublewords.
The
delimiters: parentheses are placed, in the parameter list, in separate
doublewords.
For example, if you have a
call it with the command line:
t es t pro
The scan routine sets up the parameter list:
CL8'FILE2'
If
truncated and only the first eight characters appear in the
However, no error condition results.
it is
list.