TSO/E External Functions

In addition to the built-in functions, TSO/E provides external functions that you can use to do specific tasks. Some of these functions perform the same services as control variables in the CLIST language.

The TSO/E external functions are:

GETMSG - returns in variables a system message issued during an extended MCS console session. It also returns in variables associated information about the message. The function call is replaced by a function code that indicates whether the call was successful.
LISTDSI - returns in variables the data set attributes of a specified data set. The function call is replaced by a function code that indicates whether the call was successful.
MSG - controls the display of TSO/E messages. The function returns the previous setting of MSG.
MVSVAR - uses specific argument values to return information about MVS™, TSO/E, and the current session.
OUTTRAP - traps lines of TSO/E command output into a specified series of variables. The function call returns the variable name specified.
PROMPT - sets the prompt option on or off for TSO/E interactive commands. The function returns the previous setting of prompt.
SETLANG - retrieves and optionally changes the language in which REXX messages are displayed. The function returns the previous language setting.
STORAGE - retrieves and optionally changes the value in a storage address.
SYSCPUS - returns in a stem variable information about all CPUs that are on-line.
SYSDSN - returns OK if the specified data set exists; otherwise, it returns an appropriate error message.
SYSVAR - uses specific argument values to return information about the user, terminal, language, exec, system, and console session.

Following are brief explanations about how to use the TSO/E external functions. For complete information, see z/OS TSO/E REXX Reference.