How to print dataset content using Rexx - rexx

Question

I'm trying to print the data (line by line) found in the IO.ME.DATA dataset (see my jcl).
I get the following error and looking to get the syntax right:
10 +++ DO I = 1 TO SYSTSIN.0
Error running MYREXX, line 10: Bad arithmetic conversion
I'm new to REXX. Thanks
JCL
//JCL01 JOB 000,'TEST REXX',
// CLASS=T,
// MSGCLASS=X,
// USER=ME
/*JOBPARM R=999,T=999,L=9999,S=ANY
//*
//STEPREXX EXEC PGM=IKJEFT01,PARM='MYREXX'
//SYSEXEC DD DISP=SHR,DSN=IO.ME.REXX
//SYSTSPRT DD SYSOUT=*
//SYSTSIN DD DISP=SHR,DSN=IO.ME.DATA
//
MYREXX (IO.ME.REXX)
SAY 'START OF REXX CODE.'
"EXECIO * DISKR SYSTSIN (STEM LINE. FINIS"
DO I = 1 TO SYSTSIN.0
SAY "VALUE OF I : " SYSTSIN.I
END
SAY 'END OF REXX CODE.'
DATA (from IO.ME.DATA)
MYDATA1,A
MYDATA2,B
MYDATA3,C
MYDATA4,D
MYDATA5,E

Answer 1

Try changing the do loop to
DO I = 1 TO Line.0
SAY "VALUE OF I : " Line.I
END
the command
"EXECIO * DISKR SYSTSIN (STEM LINE. FINIS"
says read the file SYSTSIN in to the stem variable Line. The number of lines read will be placed into line.0, line.1 will hold the first line in the file etc.

Answer 2

In addition to what #Bruce Martin wrote, don't point SYSTSIN to your input data. Use a different DD. IKJEFT01 uses SYSTSIN for its own purposes. Even if it works in this particular case, it's a bad habit to use DDNAMES that are known to be used for other purposes for your own.
//JCL01 JOB 000,'TEST REXX',
// CLASS=T,
// MSGCLASS=X,
// USER=ME
/*JOBPARM R=999,T=999,L=9999,S=ANY
//*
//STEPREXX EXEC PGM=IKJEFT01,PARM='MYREXX'
//SYSEXEC DD DISP=SHR,DSN=IO.ME.REXX
//SYSTSPRT DD SYSOUT=*
//SYSTSIN DD DUMMY
//MYDATA DD DISP=SHR,DSN=IO.ME.DATA
//*
This wasn't going to fit in a comment, but I felt it important to point out.