REXX External Assembler API › Execution Interfaces › Subcommand Handlers

Subcommand Handlers

These programs are executed when an ADDRESS statement or implied command statement is executed, and the specified (or current) ADDRESS subcommand environment is one that is an external program.

The routines are called as documented in the TSO/E REXX Reference:

• R0 on entry points to the environment block.
• R1 on entry points to a parameter list.
• R13 (save area address), R14 (return address), and R15 (entry point address) are standard.
• AMODE is 31 (31-bit addressing).

The parameter list has five fullwords with the top bit set in the last word. The list contains the following parameters:

• Name of the host command environment (8 characters)
• Address of the command string (4 bytes)
• Length of the command string (4 bytes)
• User token in the subcommand table entry (16 characters)
• Return code of the command (4 bytes)