Head (Unix)

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Template:More citations needed Template:Short description Template:Lowercase Script error: No such module "Infobox".Template:Template otherScript error: No such module "Check for unknown parameters".Template:Main other head is a program on Unix and Unix-like operating systems used to display the beginning of a text file or piped data.

Syntax

The command syntax is:

head [options] Template:Angbr

By default, Template:Tt will print the first 10 lines of its input to the standard output.

Option flags

Template:Glossary Template:Term Template:Term Template:Defn Template:Term Template:Term Template:Defn Template:Glossary end

Other command

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 quits 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]

Implementations

A head command is also part of ASCII's MSX-DOS2 Tools for MSX-DOS version 2.[2] The Template:Mono command has also been ported to the IBM i operating system.[3]

See also

References

Template:Reflist

External links

Template:Sister project

Script error: No such module "Navbox". Template:Core Utilities commands

  1. Script error: No such module "Citation/CS1".
  2. MSX-DOS2 Tools User's Manual by ASCII Corporation
  3. Script error: No such module "citation/CS1".