By default, head will print the first 10 lines of its input to the standard output.
Option flagsedit
-n⟨count⟩
--lines=⟨count⟩
The number of lines printed may be changed with a command line option. The following example shows the first 20 lines of filename:
head -n 20 filename
This displays the first 5 lines of all files starting with foo:
head -n 5 foo*
Most versions[citation needed] allow omitting n and instead directly specifying the number: -5. GNU head allows negative arguments for the -n option, meaning to print all but the last - argument value counted - lines of each input file.
-c⟨bytes⟩
--bytes=⟨bytes⟩
Print first x number of bytes.
Other commandedit
Many early versions of Unix and Plan 9 did not have this command, and documentation and books used sed instead:
sed 5q filename
The example prints every line (implicit) and quit after the fifth.
Equivalently, awk may be used to print the first five lines in a file:
awk 'NR < 6' filename
However, neither sed nor awk were available in early versions of BSD, which were based on Version 6 Unix, and included head.[1]
Implementationsedit
A head command is also part of ASCII's MSX-DOS2 Tools for MSX-DOS version 2.[2] The head command has also been ported to the IBM i operating system.[3]
head, unix, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, head, unix, news, newspapers, books, scholar, jstor, jun. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Head Unix news newspapers books scholar JSTOR June 2020 Learn how and when to remove this message head is a program on Unix and Unix like operating systems used to display the beginning of a text file or piped data headExample usage of head command to display first 5 lines of Lorem ipsum in the specified fileDeveloper s Various open source and commercial developersOperating systemUnix Unix like MSX DOS IBM iPlatformCross platformTypeCommandLicensecoreutils GPLv3 Contents 1 Syntax 1 1 Option flags 2 Other command 3 Implementations 4 See also 5 References 6 External linksSyntax editThe command syntax is head options file name By default head will print the first 10 lines of its input to the standard output Option flags edit n count lines count The number of lines printed may be changed with a command line option The following example shows the first 20 lines of filename head n 20 filename This displays the first 5 lines of all files starting with foo head n 5 foo Most versions citation needed allow omitting n and instead directly specifying the number 5 GNU head allows negative arguments for the n option meaning to print all but the last argument value counted lines of each input file c bytes bytes bytes Print first x number of bytes Other command editMany early versions of Unix and Plan 9 did not have this command and documentation and books used sed instead sed 5q filename The example prints every line implicit and quit after the fifth Equivalently awk may be used to print the first five lines in a file awk NR lt 6 filename However neither sed nor awk were available in early versions of BSD which were based on Version 6 Unix and included head 1 Implementations editA head command is also part of ASCII s MSX DOS2 Tools for MSX DOS version 2 2 The head command has also been ported to the IBM i operating system 3 See also edittail Unix dd Unix List of Unix commandsReferences edit Spinellis Diomidis 2022 dspinellis unix history man Version 1 0 web pages v1 1 web Zenodo doi 10 5281 zenodo 7248228 MSX DOS2 Tools User s Manual by ASCII Corporation IBM IBM System i Version 7 2 Programming Qshell PDF Retrieved 2020 09 05 External links edit nbsp The Wikibook Guide to Unix has a page on the topic of Commands head manual page from GNU coreutils FreeBSD documentation for head Retrieved from https en wikipedia org w index php title Head Unix amp oldid 1218885113, wikipedia, wiki, book, books, library,
