<language, operating system> (JCL) IBM's supremely rude script language, used to control the execution of programs in IBM OS/360's batch systems. JCL has a very fascist syntax, and some versions will, for example, barf if two spaces appear where it expects one. Most programmers confronted with JCL simply copy a working file (or card deck), changing the file names. Someone who actually understands and generates unique JCL is regarded with the mixed respect one gives to someone who memorises the phone book. It is reported that hackers at IBM itself sometimes sing "Who's the breeder of the crud that mangles you and me? I-B-M, J-C-L, M-o-u-s-e" to the tune of the "Mickey Mouse Club" theme to express their opinion of the beast. As with COBOL, JCL is often used as an archetype of ugliness even by those who haven't experienced it. However, no self-respecting mainframe MVS programmer would admit ignorance of JCL. See also fear and loathing. (1999-03-03)

<programming> A system that takes a set (a "batch") of commands or jobs, executes them and returns the results, all without human intervention. This contrasts with an interactive system where the user's commands and the computer's responses are interleaved during a single run. A batch system typically takes its commands from a disk file (or a set of punched cards or magnetic tape in the old days) and returns the results to a file (or prints them). Often there is a queue of jobs which the system processes as resources become available. Since the advent of the personal computer, the term "batch" has come to mean automating frequently performed tasks that would otherwise be done interactively by storing those commands in a "batch file" or "script". Usually this file is read by some kind of command interpreter but batch processing is sometimes used with GUI-based applications that define script equivalents for menu selections and other mouse actions. Such a recorded sequence of GUI actions is sometimes called a "macro". This may only exist in memory and may not be saved to disk whereas a batch normally implies something stored on disk. (1998-06-26)

Computerized batch processing is a method of running software programs called jobs in batches automatically. While users are required to submit the jobs, no other interaction by the user is required to process the batch.