Question

If I have a group of files with a .htm extention, how can I rename them all to .html?

mv *.htm *.html

does not work.

Answer 1

Or, you could use pure bash... (except for mv, that is..)

for file in *.htm; do mv "$file" "${file%.htm}.html"; done

and avoid the nasty basename stuff. ;)

Bash has an extensive set of variable replacement options. The one used here, '%', removes the smallest matching pattern from the. Pattern in this case is a glob pattern, so ${file%.*} would also work. The '%%' operator removes the largest matching pattern, and is interchangeable in the example above, as the pattern is fixed, ${file%%.*}.html would turn a.b.htm into a.html though.

See the variable substition section of the bash manpage for more neat tricks. There's a lot that can be done within bash directly.

Answer 2

There shouldn't be spaces, newlines or other whitespace in the filenames, but this version of freiheit's answer handles those. It also uses $() instead of backticks for readability along with other benefits.

for file in *.htm
do
    mv "$file" "$(basename "$file" .htm).html"
done

Answer 3

for file in *.htm; do
  mv $file `basename "$file" .htm`.html
done

Try it with an echo in front of the mv first time around.

The problem with your original is that "mv *.htm *.html" has the *s handled by the shell, so the mv command simply sees a list of all the .htm and .html files in the current directory. In other words, something like "mv foo.htm bar.htm stuff.htm six.htm file.htm". mv only knows how to handle more than 2 arguments if the last one is a directory.

Answer 4

rename(1) is a Perl utility that does exactly what you want. In this case:

rename 's/\.htm$/.html/' *htm

Answer 5

If you use Zsh you can use 'zmv'

Answer 6

The best tool is mmv.

mmv \*.htm #1.html

Other examples of use (and of other tools) in "GNU/Linux Command-Line Tools Summary".

Answer 7

The util-linux-ng package (on Fedora) has a rename command similar to the one mentioned by TRS-80. You can use it like this:

rename .htm .html *.html