head

- display first few lines of files

Synopsis

/usr/bin/head [-number | -n number] [filename]...

Description

The head utility copies the first number of lines of each filename to the standard output. If no filename is given, head copies lines from the standard input. The default value of number is 10 lines.

When more than one file is specified, the start of each file looks like:

==> filename <==

Thus, a common way to display a set of short files, identifying each one, is:

example% head -9999 filename1 filename2 ...

Options

The following options are supported:

-n number

The first number lines of each input file is copied to standard output. The number option-argument must be a positive decimal integer.

-number

The number argument is a positive decimal integer with the same effect as the -n number option.

If no options are specified, head acts as if -n 10 had been specified.

Operands

The following operand is supported:

filename

A path name of an input file. If no file operands are specified, the standard input is used.

Usage

See largefile(5) for the description of the behavior of head when encountering files greater than or equal to 2 Gbyte (2³¹ bytes).

Examples

Example 1 Writing the First Ten Lines of All Files

The following example writes the first ten lines of all files, except those with a leading period, in the directory:

example% head *

Environment Variables

See environ(5) for descriptions of the following environment variables that affect the execution of head: LANG, LC_ALL, LC_CTYPE, LC_MESSAGES, and NLSPATH.

Exit Status

The following exit values are returned:

0

Successful completion.

>0

An error occurred.

Attributes

See attributes(5) for descriptions of the following attributes:

See Also

cat(1), more(1), pg(1), tail(1), attributes(5), environ(5), largefile(5), standards(5)