History/Common JCL
Many of these utilities were designed by IBM users, through the group SHARE, and then modified or extended by IBM from versions originally written by a user.
These utilities are usually invoked via Job Control Language (JCL). They tend to use common JCL DD identifiers for their data sets:
- SYSIN — input file for the 'commands' for the utility. Often set to DUMMY if the default action is desired.
- SYSUT1 — input file.
- SYSUT2 — output file.
- SYSUT3 — work (spill) file for input (SYSUT1) (often not used).
- SYSUT4 — work (spill) file for output (SYSUT2) (often not used).
- SYSPRINT — output file for printed output from the utility.
- SYSOUT — output file for messages from the utility.
- SYSUDUMP — output file for a system 'dump' if the program fails.
Read more about this topic: IBM Mainframe Utility Programs
Famous quotes containing the words history and/or common:
“A great proportion of the inhabitants of the Cape are always thus abroad about their teaming on some ocean highway or other, and the history of one of their ordinary trips would cast the Argonautic expedition into the shade.”
—Henry David Thoreau (1817–1862)
“In common with other rural regions much of the Iowa farm lore concerns the coming of company. When the rooster crows in the doorway, or the cat licks his fur, company is on the way.”
—For the State of Iowa, U.S. public relief program (1935-1943)