CLIST
CLIST ( C ommand List ) is a scripting language for Time Sharing Option (TSO) on IBM - mainframes .
Historically, CLIST is important for time sharing, whereby several users can use one computer at the same time. This time-sharing option could be implemented using TSO commands in the CLIST script language. CLIST is now considered obsolete and is in practice replaced as a scripting language under TSO mainly by REXX . Knowledge of CLIST is still required if old CLIST procedures have to be maintained, for example under MVT on a Hercules system where REXX is not available.
A procedure that is coded in CLIST ("CLIST procedure") is also often referred to as CLIST for short. A CLIST procedure is loaded into main memory at execution time and interpreted there. In its simplest form, it consists of a series of TSO commands, similar to an MS-DOS batch file (* .bat).
In addition to pure TSO commands, there are variables, query options and conditional jumps. The syntax is inflexible, access to the content of source variables and built-in functions begin with the substitution character '&' and must be coded in capital letters.
For a comfortable call, CLIST procedures should be stored in a partitioned dataset in the SYSPROC concatenation , otherwise they must be qualified with the full file name using the TSO command 'EXEC'.
An example program:
PROC 0 WRITE HELLO WIKIPEDIA!
literature
- Michael Teuffel: Command procedures. In: TSO time-sharing option in the OS / 390 MVS operating system. The detailed instruction and manual for the successful TSO user. 5th edition, R. Oldenbourg Verlag, Munich 1997, ISBN 3-486-24004-8 , pp. 293-374.
Individual evidence
- ↑ CLIST and its areas of application on IBM mainframes (2006)
- ↑ IBM manual from 2000