List content of one or more files with a header showing the file name

Question

Sometime ago I read a blog that showed a misuse of a commandline command that when given a list of files serially showed the content of each file and each file had header line showing the filename of the file below it. Could someone refresh my memory?

Answer 1

You can use either tail or head for this: when given multiple files, both tools precede each file's contents with a header containing the file name.

$ for i in {1..3}; do echo line$i > file$i; done
$ tail file*
==> file1 <==
line1

==> file2 <==
line2

==> file3 <==
line3

To output the entire files instead of just the last/first 10 lines of each, use tail -n +1 or head -n -0.