Adding text to the beginning and end of a number of files?

Question

I have a number of files in a directory hierarchy. For each file, I'd like to add "abcdef" to the beginning, on its own line, and "ghijkl" to the end, on its own line. For example, if the files initially contained:

# one/foo.txt
apples
bananas

# two/three/bar.txt
coconuts

Then afterwards, I'd expect them to contain:

# one/foo.txt
abcdef
apples
bananas
ghijkl

# two/three/bar.txt
abcdef
coconuts
ghijkl

What's the best way to do this?

I've gotten as far as:

# put stuff at start of file
find . -type f -print0 | xargs -0 sed -i 's/.../abcdef/g'

# put stuff at end of file
find . -type f -print0 | xargs -0 sed -i 's/.../ghijkl/g'

but I can't seem to figure out how what to put in the ellipses.

Answer 1

This isn't a job for sed. To add lines, just use I/O redirection.

For a single file named filename, you can do the following:

mv filename temp
(echo abcdef ; cat temp ; echo ghijkl) > filename
rm temp

To do this automatically to all files in the current directory, use find and xargs:

find -type f -print0 | xargs -0 -I % sh -c '
    mv "%" temp
    (echo abcdef ; cat temp ; echo ghijkl) > "%"
'
rm temp

Answer 2

If you have GNU sed available you can use the i\ and a\ constructs:

Use line addresses to apply to first and last line respectively:

find . -type f -print0 | xargs -0 sed -i -e '1i\abcdef' -e '$a\ghijkl'

Answer 3

For files in directory as file
echo "abcde" && cat file && echo "fghijk" > file