Issuing Commands to Host System

In this REXX version all the commands are executed via command interpreter (normally COMMAND.COM)
So valid environments are:

• COMMAND, SYSTEM, DOS, '': load and execute command interpreter from COMSPEC env. variable.
• INT2E: executes commands via interrupt 2E the undocumented back door to COMMAND.COM. Normally it is faster than COMMAND environment, because there is no need to load an extra copy of COMMAND.COM before the execution of the command. Note: Commands executed through INT2E cannot be redirected to stack. There is a BUG that causes sometimes a Fatal error. While executing a cmd via INT2E and press Control-C you may have some very strange results.
• The user can create his own environments, will using the REXX interpreter as a MACRO language through a C-program with the RxRegEnvironment function Look Programming Rexx.

A command is an expression, which may include function-calls, arithmetic operations, and so on. Operators or other special characters (for example, "(" or "*") must be specified in a string if they are to appear in the issued command.

Commands to environments COMMAND, SYSTEM may return its result to REXX stack when at the end of cmd appears the string (STACK, (FIFO or (LIFO (with the parenthesis).

"dir (STACK"

If the string STACK> appears in the beginning of cmd, then stack is redirected to stdin of cmd.

"STACK> date"

Stack is flushed after redirecting it to stdin.

Redirection to or from STACK will create a temporary file with name like OAA.AAB that will be erased. It is nice to redirect all your temporary pipe files to a temporary directory. To do this set in your AUTOEXEC.BAT a new line containing:

SET TEMP=C:\TEMP

where C:\TEMP is the temporary directory (which must exist) and you must have Read/Write authority. (Look also the function LOAD)