What is best idiom to remove file extension

Ruby
1

What is the most concise, bulletproof idiom for removing the file
extension from a file? Maybe I’ve missed something obvious that
everyone else uses…

Here’s what I usually do:

This is what I usually use if I want bulletproof:
filename.sub(/#{Regexp.escape(File.extname(filename))}$/, ‘’)

I use something like this when I want something quick:
filename.sub(/.\w$/,’’)

One could imagine doing something like this, but it is comical how
much code it takes:
File.join( File.dirname(filename), File.basename(filename,
File.extname(filename)))

What do you use for this (seemingly) trivial task?

Thanks,
John

2

On Feb 23, 3:39 pm, bwv549 [email protected] wrote:

filename.sub(/.\w$/,‘’)

One could imagine doing something like this, but it is comical how
much code it takes:
File.join( File.dirname(filename), File.basename(filename,
File.extname(filename)))

Don’t forget about the 2nd argument to File.basename:

File.basename(file, File.extname(file))

If you need to guarantee the full path:

File.expand_path(File.basename(file, File.extname(file))

Regards,

Dan

3

bwv549 wrote:

What is the most concise, bulletproof idiom for removing the file
extension from a file? Maybe I’ve missed something obvious that
everyone else uses…

Here’s what I usually do:

This is what I usually use if I want bulletproof:
filename.sub(/#{Regexp.escape(File.extname(filename))}$/, ‘’)

How about:

name = fname.chomp(File.extname(fname) )

4

7stud – wrote:

How about:

name = fname.chomp(File.extname(fname) )

name = fname.chomp(File.extname(fname) ) <------

name = fname[/.*(?=…+$)/] <--------------

5

All great answers - much better than what I was doing before.

To summarize then…

full pathname with no extension:
File.expand_path(File.basename(fname, File.extname(fname))

easy to remember and read:
fname.chomp(File.extname(fname) )

shortest:
fname[/.*(?=…+$)/]

Thanks all!

6

On Tue, Feb 24, 2009 at 9:09 AM, bwv549 [email protected] wrote:

shortest:
  fname[/.*(?=..+$)/]

You can also use:

File.basename(‘foo.bar’, ‘.*’)

“foo”

^ manveru

7

Michael F. [email protected] wrote:

On Tue, Feb 24, 2009 at 9:09 AM, bwv549 [email protected] wrote:
You can also use:

File.basename(‘foo.bar’, ‘.*’)

“foo”

Be aware if it gets the result you want:
File.basename(‘foo.tar.gz’, ‘.*’)

=> “foo.tar”

However,
Jan F.

8

On Tue, Feb 24, 2009 at 5:39 AM, bwv549 [email protected] wrote:

shortest:
fname[/.*(?=..+$)/]

Note that you’ve lost your robustness with that last:

irb> fname = ‘.vimrc’
=> “.vimrc”
irb> fname[/.*(?=..+$)/]
=> “”
irb> fname.chomp(File.extname(fname) )
=> “.vimrc”

martin

9

Another summary is due:

Shortest, rock-solid idiom for removing the extension, without
removing the preceding path:

fname.chomp(File.extname(fname))

Best idiom if you are removing the path also:

File.basename(fname, ‘.*’)

It is unfortunate that these are so dissimilar, but both are easy to
remember and concise, so no problem. Thanks again for everyone’s help
on this.

10

full pathname with no extension:
File.expand_path(File.basename(fname, File.extname(fname))

File.basename(fname, ‘.*’) would be shorter. It also handles file names
like
“.vimrc” correctly.