Summary
EXEC 2 is an interpreted, command procedure control, computer scripting language used by the EXEC 2 Processor originally supplied with the CMS component of the IBM Virtual Machine/System Product (VM/SP) operating system.[1]
Relation to EXEC edit
EXEC 2 is mostly compatible[2] with CMS EXEC but EXEC 2 scripts must begin with an &TRACE statement. Some EXEC statements and predefined variables do not exist in EXEC 2, although in some cases there are analogs. There are some minor differences in some statements and predefined functions.
EXEC 2 has the following enhancements:[3]
- There is no 8-byte restriction on token length.[4]
- Statements can be up to 255 characters long.
- EXEC 2 can issue commands to subcommand environments as well as CMS and CP.
- EXEC 2 has additional built-in functions.
- EXEC 2 has user-defined functions.
- EXEC 2 commands may include subroutines and functions.
- EXEC 2 has extra debugging facilities.
- CMS programs can manipulate EXEC 2 variables.
Some statemts of EXEC are not supported in EXEC 2, including:
- &BEGSTACK ALL
- &CONTROL
- &EMSG
- &END
- &GOTO TOP
- &HEX
- &PUNCH
- &SPACE
- &TIME
Some predefined variables of EXEC are not defined in EXEC2:
- &*
- &$
- &DISKX
- &DISK*
- &DISK?
- &DOS
- &EXEC
- &GLOBAL
- &GLOBALn
- &READFLAG
- &TYPEFLAG
XEDIT Macros edit
XEDIT Macros are files with filetype XEDIT, whose contents are written using the syntax of CMS EXEC, EXEC 2 or REXX.[5] Like regular EXEC 2 "EXEC" command files, they begin with a "&TRACE" statement,[5] to distinguish them from CMS EXEC files.
History edit
Written in the 1970s[6] and formally introduced for CMS with VM/SP Release 1, EXEC 2 was preceded by CMS EXEC and superseded by REXX.
All three command interpreters—CMS EXEC, EXEC 2 and REXX — continue to be supported by z/VM.
References edit
- ^ Varian, Melinda. "VM AND THE VM COMMUNITY: Past, Present, and Future" (PDF). Retrieved March 14, 2012.
- ^ "Appendix A: CMS EXEC and EXEC 2 Relationship". IBM Virtual Machine/Sysrem Product: EXEC 2 Reference - Program Number 5664-167 - Release 2 (PDF). IBM. pp. 48–55. SC24-5219-1. Retrieved April 29, 2022.
{{cite book}}:|work=ignored (help) - ^ IBM Corporation. "EXEC 2 Processor and CMS EXEC Processor". Retrieved March 14, 2012.
- ^ "EXEC 2 Processor and CMS EXEC Processor". IBM.
- ^ a b EXEC 2 Reference (PDF). p. 92. Archived from the original (PDF) on 2017-01-20. Retrieved 2017-12-03.
- ^ "EXEC 2".
External links edit
- EXEC 2 Processor, CMS User's Guide, z/VM Version 5 Release 1.0, Program Number 5741-A05, Document Number SC24-6079-00, First Edition September 2004
- REX - A Command Programming Language, REX First Public Paper, SHARE 56, 18 Feb 1981