{{Unreferenced, date=December 2009 The Symbolic Stream Generator (or SSG) is a software productivity aid by

Unisys Unisys Corporation is an American multinational information technology (IT) services and consulting company headquartered in Blue Bell, Pennsylvania. It provides digital workplace solutions, cloud, applications, and infrastructure solutions, e ...

for their

mainframe computer A mainframe computer, informally called a mainframe or big iron, is a computer used primarily by large organizations for critical applications like bulk data processing for tasks such as censuses, industry and consumer statistics, enterpris ...

s of the former

UNIVAC 1100/2200 series The UNIVAC 1100/2200 series is a series of compatible 36-bit computer systems, beginning with the UNIVAC 1107 in 1962, initially made by Sperry Rand. The series continues to be supported today by Unisys Corporation as the ClearPath Dorado Series. ...

. SSG is used to generate RUN-Streams (corresponding to IBM's

Job Control Language Job Control Language (JCL) is a name for scripting languages used on IBM mainframe operating systems to instruct the system on how to run a batch job or start a subsystem. More specifically, the purpose of JCL is to say which programs to run, us ...

), apply and administer symbolic changes to program

source Source may refer to: Research * Historical document * Historical source * Source (intelligence) or sub source, typically a confidential provider of non open-source intelligence * Source (journalism), a person, publication, publishing institute o ...

s as a form of

version control In software engineering, version control (also known as revision control, source control, or source code management) is a class of systems responsible for managing changes to computer programs, documents, large web sites, or other collections o ...

, and for many other purposes. An SSG program (i.e., its "job control

script Script may refer to: Writing systems * Script, a distinctive writing system, based on a repertoire of specific elements or symbols, or that repertoire * Script (styles of handwriting) ** Script typeface, a typeface with characteristics of handw ...

") is called a ''Skeleton'', and its programming language Symstream. The tool created output streams based on interpreting data provided via multiple input sources. It was originally created by Univac for the creation of Operating System (OS) updates. It was later adopted by the general user community for the creation of complex batch and real-time computer processes. The sources could recursively reference additional sources, providing wide flexibility in input parsing. The rules for output creation were also in source files, with similar levels of dynamic input capability. Interpretation of the multiple input sources allowed for dynamic creation of output stream content. Complex recursive processes could be applied to create program source code, job execution sequences, simulated dynamic input from virtual consoles, and in general provide scripting capabilities reminiscent of the Unix GREP and YACC tools.

See also