head (Unix)

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head is a program on Unix and Unix-like systems used to display the beginning of a text file or piped data. The command syntax is:

head [options] <file_name>

By default, 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 the n and just let you say -5. GNU head allows negative arguments for -n option, meaning to print all but the last - argument value counted - lines of each input file.

Flags[edit]

-c <x number of bytes> Copy first x number of bytes.

Other[edit]

Many early versions of Unix did not have this command, and so documentation and books had sed do this job:

sed 5q foo

This says to print every line (implicit), and quit after the fifth.

See also[edit]

External links[edit]