CB UNIX

{{Short description|Unix variant developed by the Columbus, Ohio branch of Bell Labs}}

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| name = Columbus UNIX / CB UNIX

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| developer = Bell Labs

| family = Unix

| working state = Discontinued

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| programmed in = C

| language = English

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| ui = Command-line interface

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Columbus UNIX, or CB UNIX, is a discontinued variant of the UNIX operating system used internally at Bell Labs{{cite book |last=Rochkind |first=Marc |authorlink=Marc Rochkind |title=Advanced UNIX Programming |url=https://archive.org/details/advancedunixprog00roch |url-access=registration |publisher=Prentice Hall |year=1985 |pages=[https://archive.org/details/advancedunixprog00roch/page/156 156–157] |isbn=0-13-011800-1}} for administrative databases and transaction processing. It was developed at the Columbus, Ohio branch, based on V6, V7 and PWB Unix.{{cite book |editor=J. D. Doan |title=CB-UNIX Programmer's Manual, Edition 2.3 |date=May 1981 |page=iii |publisher=Bell Telephone Laboratories |location=Columbus, OH |url=http://www.tuhs.org/Archive/Distributions/USDL/CB_Unix/cbunix_intro.pdf}} It was little-known outside the company.

CB UNIX was developed to address deficiencies inherent in Research Unix, notably the lack of interprocess communication (IPC) and file locking, considered essential for a database management system. Several Bell System operation support system products were based on CB UNIX such as Switching Control Center System. The primary innovations were power-fail restart, line disciplines, terminal types, and IPC features.{{cite newsgroup

|title = UNIX history

|author = Dale Dejager

|date = 1984-01-16

|newsgroup = net.unix

|url = https://groups.google.com/group/net.unix/msg/b80689d4b3bff13f?dmode=source

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File:CB Unix Manuals.jpg

The interprocess communication features developed for CB UNIX were message queues, semaphores and shared memory support. These eventually appeared in mainstream Unix systems starting with System V in 1983, and are now collectively known as System V IPC.{{cite book |title=The Linux Programming Interface |url=https://archive.org/details/linuxprogramming00kerr |url-access=limited |last=Kerrisk |first=Michael |year=2010 |publisher=No Starch Press |page=[https://archive.org/details/linuxprogramming00kerr/page/n964 921]|isbn=9781593272203 }}