ARCHIVED: In Unix, what do some obscurely named commands stand for?
A list of some of the more obscurely named Unix commands follows:
awk
- Aho, Weinberger, and Kernighan
The awk scripting language was named by its authors, Al Aho, Peter Weinberger, and Brian Kernighan. For more, see ARCHIVED: What is awk, and how do I use it?
grep
- Global regular expression print
The grep command comes from the command used by the
ed
program (a simple and venerable Unix text editor) to print all lines matching a certain pattern:g/re/p
For more, see About grep
fgrep
- Fixed grep
The
fgrep
command searches for fixed strings only, possibly taking the strings from another file. The "f" does not stand for "fast"; in fact, at times, using thefgrep
command can be slower than using theegrep
command. However, thefgrep
command may still be useful when searching a file for a larger number of strings than theegrep
command can handle. egrep
- Extended grep
The
egrep
command uses fancier regular expressions than thegrep
command. Many people use theegrep
command for its internal algorithms, which are more sophisticated than thegrep
andfgrep
commands. Also, theegrep
command is usually the fastest of the three programs. cat
- Catenate
"Catenate" is an obscure word meaning "to connect in a series", which is what the
cat
command does to one or more files. This is not to be confused with C/A/T, the Computer Aided Typesetter. For more, see Combine several text files into a single file in Unix nroff
,troff
- New roff, Typesetter new roff
These two commands are descendants of the
roff
command, which was a re-implementation of the Multicsrunoff
program. Therunoff
program would "run off" a good copy of a document. tee
- T
The
tee
command is named after plumbing terminology for a T-shaped pipe splitter. This Unix command splits the output of another command, sending it to a file and to the terminal. biff
- A dog named Biff
This command, which turns on asynchronous mail notification, was actually named after a dog. Courtesy of Eric Cooper, Carnegie Mellon University:
"I can confirm the origin of
biff
, if you're interested. Biff was Heidi Stettner's dog, back when Heidi (and I, and Bill Joy) were all grad students at U.C. Berkeley and the early versions of BSD were being developed. Biff was popular among the residents of Evans Hall, and was known for barking at the mailman, hence the name of the command." rc
- runcom (as in
.cshrc
or/etc/rc
)The
rc
command derives from theruncom
facility from the MIT CTSS system, ca. 1965. From Brian Kernighan and Dennis Ritchie, as told to Vicki Brown:"There was a facility that would execute a bunch of commands stored in a file; it was called
Note: The name of the shell from the Plan 9 operating system is alsoruncom
for "run commands", and the file began to be called "a runcom".rc
in Unix is a fossil from that usage."rc
. - Perl
- Practical extraction and report language
The Perl language is a text, process, and file manipulation tool, created by Larry Wall. Perl bridges the gap between shell and C programming, and is free and completely portable. The acronym is one of many variants proposed, with varying degrees of seriousness, as the true origin of the name. However, this is currently regarded as apocryphal. Spelling Perl as "PERL", as though it is an acronym, is incorrect. For further information, see the Usenet newsgroup
comp.lang.perl
and the Perl FAQ.
For more interesting tidbits, see the book Life with Unix by Don Libes.
At Indiana University, for personal or departmental Linux or Unix systems support, see Get help for Linux or Unix at IU.
This is document abnd in the Knowledge Base.
Last modified on 2018-01-18 08:57:22.