Using CLIST CONTROL and REXX TRACE statements

You can display a statement from a macro as it is being interpreted and run. Use either of these:

A CLIST CONTROL statement with the LIST, SYMLIST, or CONLIST operand
A REXX TRACE statement with the A, I, L, O, R, or S operand

These statements produce messages on your display screen similar to the WRITE and SAY statements discussed in the previous section. However, several differences should be noted:

For the CLIST CONTROL statement:
- LIST displays commands and subcommands (including ISREDIT statements) after substitution but before processing. This allows you to see an ISREDIT statement in the form that the editor sees the statement.
- CONLIST displays a CLIST statement (for example, IF, DO, SET) after substitution but before processing. You might be able to tell why an IF statement did not work properly by using CONLIST.
- SYMLIST displays both CLIST and command lines before symbolic substitution, allowing you to see the lines as written.
Use the NOLIST, NOSYMLIST, and NOCONLIST operands to prevent the display of statements. See z/OS TSO/E CLISTs for more details.
For the REXX TRACE statement:
- The A operand traces all clauses displaying the results of each clause.
- The I operand traces the intermediate results, displaying both the statement and the results.
- The L operand traces labels in your edit macro.
- The O operand stops, or turns off, the trace.
- The R operand, which is used most often, traces all clauses and expressions.
- The S operand scans each statement, displaying it without processing it.

See z/OS TSO/E REXX Reference and z/OS TSO/E REXX User's Guide for more details.