Concatenate multiple files but include filename as section headers

I would like to concatenate a number of text files into one large file in terminal. I know I can do this using the cat command. However, I would like the filename of each file to precede the "data dump" for that file. Anyone know how to do this?

what I currently have:

file1.txt = bluemoongoodbeer

file2.txt = awesomepossum

file3.txt = hownowbrowncow

cat file1.txt file2.txt file3.txt

desired output:

file1

bluemoongoodbeer

file2

awesomepossum

file3

hownowbrowncow

Was looking for the same thing, and found this to suggest:

tail -n +1 file1.txt file2.txt file3.txt

Output:

==> file1.txt <==
<contents of file1.txt>

==> file2.txt <==
<contents of file2.txt>

==> file3.txt <==
<contents of file3.txt>

If there is only a single file then the header will not be printed. If using GNU utils, you can use -v to always print a header.

I used grep for something similar:

grep "" *.txt

It does not give you a 'header', but prefixes every line with the filename.

This should do the trick as well:

find . -type f -print -exec cat {} \;

Means:

find    = linux `find` command finds filenames, see `man find` for more info
.       = in current directory
-type f = only files, not directories
-print  = show found file
-exec   = additionally execute another linux command
cat     = linux `cat` command, see `man cat`, displays file contents
{}      = placeholder for the currently found filename
\;      = tell `find` command that it ends now here

You further can combine searches trough boolean operators like -and or -or. find -ls is nice, too.

This should do the trick:

for filename in file1.txt file2.txt file3.txt; do
    echo "$filename"
    cat "$filename"
done > output.txt

or to do this for all text files recursively:

find . -type f -name '*.txt' -print | while read filename; do
    echo "$filename"
    cat "$filename"
done > output.txt