How to mass rename files in ruby

Question

I have been trying to work out a file rename program based on ruby, as a programming exercise for myself (I am aware of rename under linux, but I want to learn Ruby, and rename is not available in Mac).

From the code below, the issue is that the .include? method always returns false even though I see the filename contains such search pattern. If I comment out the include? check, gsub() does not seem to generate a new file name at all (i.e. file name remains the same). So can someone please take a look at see what I did wrong? Thanks a bunch in advance!

Here is the expected behavior: Assuming that in current folder there are three files: a1.jpg, a2.jpg, and a3.jpg The Ruby script should be able to rename it to b1.jpg, b2.jpg, b3.jpg

#!/Users/Antony/.rvm/rubies/ruby-1.9.3-p194/bin/ruby

puts "Enter the file search query"
searchPattern = gets
puts "Enter the target to replace"
target = gets
puts "Enter the new target name"
newTarget = gets
Dir.glob("./*").sort.each do |entry|
  origin = File.basename(entry, File.extname(entry))
  if origin.include?(searchPattern)
    newEntry = origin.gsub(target, newTarget)
    File.rename( origin, newEntry )
    puts "Rename from " + origin + " to " + newEntry
  end
end

Answer 1

Your problem is that gets returns a newline at the end of the string. So, if you type "foo" then searchPattern becomes "foo\n". The simplest fix is:

searchPattern = gets.chomp

---

I might rewrite your code slightly:

$stdout.sync
print "Enter the file search query: "; search  = gets.chomp
print "Enter the target to replace: "; target  = gets.chomp
print "  Enter the new target name: "; replace = gets.chomp
Dir['*'].each do |file|
  # Skip directories
  next unless File.file?(file)
  old_name = File.basename(file,'.*')
  if old_name.include?(search)
    # Are you sure you want gsub here, and not sub?
    # Don't use `old_name` here, it doesn't have the extension
    new_name = File.basename(file).gsub(target,replace)
    File.rename( file, new_path )
    puts "Renamed #{file} to #{new_name}" if $DEBUG
  end
end

Answer 2

I made a small script to rename the entire DBZ serie by seasons and implement this:

count = 1
new_name = "Dragon Ball Z S05E"
format_file = ".mkv"
Dir.glob("dragon ball Z*").each do |old_name|
  File.rename(old_name, new_name + count.to_s + format_file)
  count += 1
end

The result would be: Dragon Ball Z S05E1 Dragon Ball Z S05E2 Dragon Ball Z S05E3