rename - rename multiple files.
Rename all files matching "*.bak" to strip the extension:
rename 's/\e.bak$//' *.bak
Rename all files uppercase names to lowercase:
rename 'y/A-Z/a-z/' *
Rename all files matching "*.html" to "*.htm":
rename 's/.html/.htm/' *
Rename all files matching "*.html" to "*.htm" and show the result:
rename -v 's/.html/.htm/' *
Display the names of files to be renamed, but don't rename:
rename -n 's/.html/.htm/' *