Many versions of BSD UNIX include a nice program called head
prints the top
(default: 10) lines of a file.
System V or other users without head
emulate its behavior with sed
The easiest way is simply to use
If you want to get fancy, you can use a shell script
to emulate all of the behavior of the BSD head
command, including taking an option for the number of lines to be
printed, and printing a separator line if multiple filenames are
specified on the same command line.
The CD-ROM has that script.
Most of it is straightforward.
One interesting part is shown below.
It's the sed
command that prints the separator when more than one
file is shown:
==> $1 <==
inserts the separator before line 1.
quits after the number of lines
(by default, 10) in the
shell variable (6.8
The shell substitutes
with the filename being read.
The double quotes (
) around the sed
commands let the
shell build the commands on-the-fly before starting sed