From: ara.t.howard@...
Date: 2006-02-17T13:06:40+09:00
Subject: Re: Ruby script to Module/Class refactor

On Fri, 17 Feb 2006, William James wrote:

> William James wrote:
>> James B. Byrne wrote:
>>
>>> # find, move and optionally rename data files that match glob expression
>>> # provided.
>>> #
>>> # ruby mv2dir.rb source_dir glob_exp [target_dir=./] [ext]
>>
>> # ruby mv2dir.rb source_dir glob_exp target_dir
>> require 'fileutils'
>> Dir[ File.join(ARGV[0], "*") ].select{ |p|
>>   Regexp.new(ARGV[1]).match File.basename( p ) }.each{ |p|
>>   FileUtils.move( p, ARGV[2] ) }
>
> Please pardon previous prolixity.
>
> require 'fileutils'
> FileUtils.move Dir[ File.join(ARGV[0], "*") ].select{ |p|
>  Regexp.new(ARGV[1]).match File.basename( p ) }, ARGV[2]

a glob is not a regexp

   harp:~ > irb
   irb(main):001:0> Dir::glob "*.{jpg,png}"
   => ["mqmapgend.png", "tshirt2.png", "tshirt.png", "boulder.png", "map.png", "seg_lights.png"]


   irb(main):002:0> Dir::glob("*").select{|file| file =~ /*.{jpg,png}/}
   SyntaxError: compile error
   (irb):2: invalid regular expression; there's no previous pattern, to which '*' would define cardinality at 1: /*.{jpg,png}/
           from (irb):2
           from :0


so almost any valid glob will explode the above when it fails to compile as a
regexp.

also, for large dirs this will be extremely slow since all results are returned
at once.  best to use the block form of globbing to accomplish this

   harp:~ > ls *png
   boulder.png  map.png  mqmapgend.png  seg_lights.png  tshirt.png  tshirt2.png


   harp:~ > cat a.rb
   (src, glob, dst, ext = ARGV) and (dst ||= ".") and (f = File)
   Dir::glob(f.join(src, glob)){|e| f.rename(e, f.join(dst, f.basename(e) + ext.to_s))}


   harp:~ > ruby a.rb . '*.png' tmp .bak


   harp:~ > ls tmp
   boulder.png.bak  map.png.bak  mqmapgend.png.bak  seg_lights.png.bak  tshirt.png.bak  tshirt2.png.bak


regards.

-a

-- 
judge your success by what you had to give up in order to get it.
- h.h. the 14th dali lama