One-liner for lowercasing files

Ruby
1

Hi,
Can someone please suggest a simple Ruby one-liner to lowercase a
filename (in a directory)? I’ve perused, with Google, a bunch of good
Ruby one-liner sites, but, I can’t find any lowercasing examples.

Thanks a lot,
Peter

2

Peter B. wrote:

Can someone please suggest a simple Ruby one-liner to lowercase a
filename (in a directory)?

Lowercase the contents of a file, or its name ?

For the contents, this example lifted almost verbatim from “man ruby”.

ruby -p -i.bak -e ‘$_.downcase!’ /tmp/junk

To lowercase the names of all files:

Dir["*"].each { |fn| File.rename(fn, fn.downcase) }

Beware that even ruby 1.9 won’t lowercase anything other than plain A-Z.

3

Thanks, Brian. Yes, it’s just filename I want, not content. But, this is
what I get when I try your suggestion:

ruby Dir.glob("*").each { |fn| File.rename(fn, fn.downcase) }
‘file’ is not recognized as an internal or external command,
operable program or batch file.

Brian C. wrote:

Peter B. wrote:

Can someone please suggest a simple Ruby one-liner to lowercase a
filename (in a directory)?

Lowercase the contents of a file, or its name ?

For the contents, this example lifted almost verbatim from “man ruby”.

ruby -p -i.bak -e ‘$_.downcase!’ /tmp/junk

To lowercase the names of all files:

Dir["*"].each { |fn| File.rename(fn, fn.downcase) }

Beware that even ruby 1.9 won’t lowercase anything other than plain A-Z.

4

On Dec 14, 2009, at 1:17 PM, Peter B. wrote:

Thanks, Brian. Yes, it’s just filename I want, not content. But,
this is
what I get when I try your suggestion:

ruby Dir.glob("*").each { |fn| File.rename(fn, fn.downcase) }
‘file’ is not recognized as an internal or external command,
operable program or batch file.

Try

ruby -e ‘Dir.glob("*").each { |fn| File.rename(fn, fn.downcase) }’

Otherwise, Dir.glob… will be seen as a shell command, not as ruby
code.

Regards,
Florian

5

On Dec 14, 12:04 pm, Peter B. [email protected] wrote:

Still no good. Here’s what I get:

ruby -e ‘Dir.glob(“.”).each { |fn| File.rename(fn, fn.downcase) }’

‘fn’ is not recognized as an internal or external command,
operable program or batch file.

E:\Asura-Non\BWDhelp\temp>

Do not top-post.

Since you are using the windoze shell, you must learn some things
about the windoze shell. Does that make sense?

In this case, the Ruby code must be enclosed in double quotes.
Try this.

ruby -e “Dir[‘*’].each{|fn| p fn.downcase }”

6

w_a_x_man wrote:

On Dec 14, 12:04�pm, Peter B. [email protected] wrote:

Still no good. Here’s what I get:

ruby -e ‘Dir.glob(“.”).each { |fn| File.rename(fn, fn.downcase) }’

‘fn’ is not recognized as an internal or external command,
operable program or batch file.

E:\Asura-Non\BWDhelp\temp>

Do not top-post.

Since you are using the windoze shell, you must learn some things
about the windoze shell. Does that make sense?

In this case, the Ruby code must be enclosed in double quotes.
Try this.

ruby -e “Dir[‘*’].each{|fn| p fn.downcase }”

Here’s what worked. Yours worked, waxman, but I needed a real filename
conversion, not just a print of it.
Thank you all for your help! This is great, simple stuff.

ruby -e “Dir.glob(‘*’).each{|fn| File.rename(fn, fn.downcase) }”

7

Still no good. Here’s what I get:

ruby -e ‘Dir.glob(".").each { |fn| File.rename(fn, fn.downcase) }’
‘fn’ is not recognized as an internal or external command,
operable program or batch file.

E:\Asura-Non\BWDhelp\temp>

Florian G. wrote:

On Dec 14, 2009, at 1:17 PM, Peter B. wrote:

Thanks, Brian. Yes, it’s just filename I want, not content. But,
this is
what I get when I try your suggestion:

ruby Dir.glob("*").each { |fn| File.rename(fn, fn.downcase) }
‘file’ is not recognized as an internal or external command,
operable program or batch file.

Try

ruby -e ‘Dir.glob("*").each { |fn| File.rename(fn, fn.downcase) }’

Otherwise, Dir.glob… will be seen as a shell command, not as ruby
code.

Regards,
Florian

8

2009/12/14 Peter B. [email protected]:

Here’s what worked. Yours worked, waxman, but I needed a real filename
conversion, not just a print of it.
Thank you all for your help! This is great, simple stuff.

ruby -e “Dir.glob(‘*’).each{|fn| File.rename(fn, fn.downcase) }”

Note that if you use a directory name in Dir[‘*’] you need to make
sure the dirname remains unchanged. Then you might rather do

ruby -e ‘Dir[“path/*”].each {|f| d, p = File.split(f); File.rename(f,
File.join(d, p.downcase))}’

Kind regards

robert