mmv

Move and rename files in bulk. More information: https://manned.org/mmv.1.

• Rename all files with a certain extension to a different extension:
  mmv "*{{.old_extension}}" "#1{{.new_extension}}"
• Copy report6part4.txt to ./french/rapport6partie4.txt along with all similarly named files:
  mmv -c "{{report*part*.txt}}" "{{./french/rapport#1partie#2.txt}}"
• Append all .txt files into one file:
  mmv -a "{{*.txt}}" "{{all.txt}}"
• Convert dates in filenames from "M-D-Y" format to "D-M-Y" format:
  mmv "{{[0-1][0-9]-[0-3][0-9]-[0-9][0-9][0-9][0-9].txt}}" "{{#3#4-#1#2-#5#6#7#8.txt}}"