The CLIST language enables you to work more efficiently with TSO/E. You can write programs, called CLISTs, that perform given tasks or groups of tasks. From then on, you can simply invoke the CLISTs to do those tasks.
What is CLIST
The term CLIST (pronounced “sea list”) is short for Command LIST, because the most basic CLISTs are lists of TSO/E commands. When you invoke such a CLIST, it issues the TSO/E commands in sequence. Download CLIST pdf at free of cost.
Besides issuing TSO/E commands, CLISTs can perform more complex programming tasks. The CLIST language includes the programming tools you need to write extensive, structured applications.
Purpose of CLIST
CLISTs can perform any number of complex tasks, from displaying a series of full-screen panels to managing programs written in other languages.
The CLIST language is an interpretive language. Like programs in other high-level interpretive languages, CLISTs are easy to write and test. You don’t have to compile and link-edit them. To test a CLIST, you execute it, correct any errors, and re-execute it. The CLIST language is one of two command languages available in TSO/E.
According to Wiki the CLIST is as follows:
CLIST (Command List) (pronounced “C-List”) is a procedural programming language for TSO in MVS systems. It originated in OS/360 Release 20 and has assumed a secondary role since the availability of Rexx in TSO/E Version 2. The term CLIST is also used for command lists written by users of NetView.[1]
In its basic form, a CLIST program (or “CLIST” for short) can take the form of a simple list of commands to be executed in strict sequence (like a DOS batch file (*.bat) file). However, CLIST also features If-Then-Else logic as well as loop constructs. The best available book on CLIST find here.
CLIST is an interpreted language. That is, the computer must translate a CLIST every time the program is executed.
CLISTs, therefore, tend to be slower than programs written in compiled languages such as COBOL, FORTRAN, or PL/1. (A program written in a compiled language is translated once to create a “load module” or executable.)
CLIST can read/write MVS files and read/write from/to a TSO terminal. It can read parameters from the caller and also features a function to hold global variables and pass them between CLISTs.
A CLIST can also call an MVS application program (written in COBOL or PL/I, for example). CLISTs can be run in background (by running JCL which executes the TSO control program (IKJEFT01)). TSO I/O screens and menus using ISPF dialog services can be displayed by CLISTs.
Compare the function of CLIST with that provided by REXX.
Best CLIST example
1 /********************************************************************/
2 /* MULTI-LINGUAL "HELLO WORLD" PROGRAM. */
3 /* */
4 /* THIS CLIST, STORED AS USERID.TSO.CLIST(TEST), CAN BE INVOKED */
5 /* FROM THE ISPF COMMAND LINE AS SHOWN IN THE FOLLOWING EXAMPLE: */
6 /* */
7 /* COMMAND ===> TSO TEST SPANISH */
8 /* */
9 /********************************************************************/
10 PROC 1 LANGUAGE
11 IF &LANGUAGE = SPANISH THEN +
12 WRITE HOLA, MUNDO
13 ELSE IF &LANGUAGE = FRENCH THEN +
14 WRITE BONJOUR, MONDE
15 ELSE +
16 WRITE HELLO, WORLD
17 EXITRelated Posts
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