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 will look like:

==> filename <==

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

example% head -9999 filename1 filename2 ...

The following options are supported:

-n number

The first number lines of each input file will be 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 will act as if -n 10had been specified.

The following operand is supported:

file

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

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

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

The following exit values are returned:

0

Successful completion.

>0

An error occurred.

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

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