TERSE is an
IBM archive file format
In computing, an archive file is a computer file that is composed of one or more files along with metadata. Archive files are used to collect multiple data files together into a single file for easier portability and storage, or simply to compres ...
that supports
lossless compression
Lossless compression is a class of data compression that allows the original data to be perfectly reconstructed from the compressed data with no loss of information. Lossless compression is possible because most real-world data exhibits statistic ...
. A TERSE file may contain a sequential data set, a
partitioned data set (PDS), partitioned data set extended (PDSE), or a ''large format dataset'' (DSNTYPE=LARGE). Any record format (RECFM) is allowed as long as the record length is less than 32 K (64 K for RECFM=VBS). Records may contain printer control characters.
Terse files are compressed using a modification of
Ziv, Lempel compression algorithm developed by
Victor S. Miller
Victor Saul Miller (born 3 March 1947 in Brooklyn, New York) is an American mathematician as a Principal Computer Scientist in the Computer Science Laboratory of SRI International. He received his B.A. in mathematics from Columbia University in ...
and
Mark Wegman
Mark N. Wegman is an American computer scientist known for his contributions to algorithms and compiler optimization. Wegman received his B.A. from New York University and his Ph.D. from the University of California, Berkeley. He joined IBM Res ...
at the
Thomas J. Watson Research Center in
Yorktown Heights, New York.
The Terse algorithm was proprietary to IBM; however, IBM has released an open source Java decompressor under the Apache 2 license. The compression/decompression program (called ''terse'' and ''unterse'')—AMATERSE or TRSMAIN—is available from IBM for
z/OS; the
z/VM equivalents are the
TERSE and
DETERSE commands, for sequential datasets only. Versions for
PC DOS,
OS/2,
AIX
Aix or AIX may refer to:
Computing
* AIX, a line of IBM computer operating systems
*An Alternate Index, for a Virtual Storage Access Method Key Sequenced Data Set
*Athens Internet Exchange, a European Internet exchange point
Places Belgium
...
,
Windows
Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...
(2000,XP,2003),
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...
, and
Mac OS/X are available online.
AMATERSE
The following JCL can be used to invoke AMATERSE on z/OS (TRSMAIN uses INFILE and OUTFILE instead of SYSUT1 and SYSUT2):
[
ppppp is PACK (compress),
SPACK (compress, slower and compresses better), or
UNPACK (uncompress)
]
//jobname JOB ...
//stepname EXEC PGM=AMATERSE,PARM=ppppp
//SYSPRINT DD SYSOUT=*
//SYSUT1 DD DISP=SHR,DSN=input.dataset
//SYSUT2 DD DISP=(NEW,CATLG),DCB=ddd,DSN=output.dataset,
// SPACE=space_parameters
//SYSUT3 DD DISP=(NEW,DELETE),SPACE=space_parameters Optional temporary dataset
Uses
Terse can be used as a general-purpose compression/decompression tool. IBM also distributes downloadable
Program temporary fix In IBM terminology, a Program temporary fix or Product temporary fix (PTF), sometimes depending on date, is a single bug fix, or group of fixes, distributed in a form ready to install for customers.
A PTF normally follows an APAR (Authorized Progra ...
s (PTFs) as tersed datasets. Terse is also used by IBM customers to package diagnostic information such as z/OS dumps and traces, for transmission to IBM.
References
External links
Terse PC versions at Vetusware
IBM software
Archive formats
Data compression
American inventions
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