How to rename multiple files by replacing word in file name?

rename 's/ACDC/AC-DC/' *.xxx

from man rename

DESCRIPTION
       "rename" renames the filenames supplied according to the rule specified as the 
first argument.  The perlexpr argument is a Perl expression which is expected to modify the 
$_ string in Perl for at least some of the filenames specified.  If a given filename is not 
modified by the expression, it will not be renamed.  If no filenames are given on
           the command line, filenames will be read via standard input.

For example, to rename all files matching "*.bak" to strip the extension, you might say

rename 's/\.bak$//' *.bak

To translate uppercase names to lower, you'd use

rename 'y/A-Z/a-z/' *

This answer contains the good parts from all other answers, while leaving out such heresy as ls | while read.

Current directory:

for file in ACDC*.xxx; do
    mv "$file" "${file//ACDC/AC-DC}"
done

Including subdirectories:

find . -type f -name "ACDC*" -print0 | while read -r -d '' file; do
    mv "$file" "${file//ACDC/AC-DC}"
done

Newline characters are really unlikely to be in filenames, so this can be simpler while still working with names containing spaces:

find . -type f -name "ACDC*" | while read -r file; do
    mv "$file" "${file//ACDC/AC-DC}"
done

To use the util-linux version of rename that Phil referred to (on Ubuntu, it's called rename.ul):

rename ACDC AC-DC ACDC*

or

rename.ul ACDC AC-DC ACDC*

Using the bash shell

find . -type f -name "ACDC*" -print0 | while read -d $'\0' f
do
   new=`echo "$f" | sed -e "s/ACDC/AC-DC/"`
   mv "$f" "$new"
done

Note: using find will process the current directory, and the directories under.

Depends on your shell. In zsh, I'd do this:

for file in ACDC*.xxx; do
    mv "$file" "$(echo $file | sed -e 's/ACDC/AC-DC/')"
done

Probably not the best solution, but works.

Using bash:

ls *.xxx | while read fn; do
    mv "${fn}" "${fn/ACDC/AC-DC}";
done

If you have the rename program installed:

rename 's/ACDC/AC-DC/' *.xxx