How to batch rename files in bash

bash

I've got some files like this:

database1-backup-01-01-2011.sql
database2-backup-01-01-2011.sql

…etc. I want to rename them to add AM, like this:

database1-backup-01-01-2011-AM.sql
database2-backup-01-01-2011-AM.sql

What's the most concise way to do that from the bash shell?

Another option:

for i in *.sql ; do
    mv -v $i ${i%.sql}-AM.sql
done

This loops through all the .sql files and renames them to end in -AM.sql instead.

PROTIP: Use $(command) instead of `command` in your scripts (and command-lines), it makes quoting and escaping less of a nightmare.

I also like the rename command that John T posted, but it's not available on all systems. This should work everywhere:

for i in *.png; do mv -v $i `basename $i .png`.test.png; done

To protect files with 3 digits already

for f in "file #"*.ext; do
  num=${f#file #}
  num=${num%.ext}
  new=$(printf "file #%03d.ext" $num)
  echo mv "$f" "$new"
done

This will display in the console the commands to execute, but not actually rename the files.

Once you are happy with what it intends to do, you can make it rename the files by removing the word echo and re-running it.