|Developer(s)||Various open-source and commercial developers|
|Operating system||Unix, Unix-like, MSX-DOS, IBM i|
head is a program on Unix and Unix-like operating systems used to display the beginning of a text file or piped data.
The command syntax is:
head [options] <file_name>
head will print the first 10 lines of its input to the standard output. 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 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 <x number of bytes> Copy first x number of bytes.
Many early versions of Unix 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.
head command is also part of ASCII's MSX-DOS2 Tools for MSX-DOS version 2. The head command has also been ported to the IBM i operating system.