Copy the first part of files (POSIX)
head [-number] [-c|-l] [-n number] [file]...
The head utility copies its input files to the standard output. The utility ends the output for each file at a point designated by the -n number option. The number argument is counted in bytes if you choose the -c option, and in lines if you choose the -l option.
If you specify multiple files, head prints an identifying header before the output for each file.
Display the first ten lines of all files in the current directory:
head *
Print the first 16 bytes of myfile in hex:
head -c -n 16 myfile | hd
(Note that in this case, the same functionality is offered through command-line options to hd.)