Create an empty file of certain size

Ruby
1

Hi,

I need to create an empty (or at least garbage) file of a certain size.
I’m doing it the way below, but it is rather slow – any ideas on a
quicker way?

File.open(“tmp.txt”, ‘w’) { |f| 10.megabytes.times { f.write “a” } }

Thanks!

~ Mark

2

On May 15, 2008, at 4:09 PM, Mark D. wrote:

~ Mark

fd.truncate( 2 ** 20 )

a @ http://codeforpeople.com/

3

fd.truncate( 2 ** 20 )

Thanks that’s great, didn’t know about that method!

4

Robert K. wrote:

2008/5/16 Mark D. [email protected]:

fd.truncate( 2 ** 20 )

Thanks that’s great, didn’t know about that method!

If it does not work on your platform, you can speed up your solution
by writing larger chunks:

BUFFER = (“a” * 1024).freeze
File.open(“tmp.txt”, ‘wb’) { |f| 10.kilobytes.times { f.write BUFFER } }

Here is another way:

size = 2**30
File.open(“tmp.txt”,“wb”){|f|f.seek(size-1);f.write(“\0”)}

Regards,

Park H.

5

2008/5/16 Mark D. [email protected]:

fd.truncate( 2 ** 20 )

Thanks that’s great, didn’t know about that method!

If it does not work on your platform, you can speed up your solution
by writing larger chunks:

BUFFER = (“a” * 1024).freeze
File.open(“tmp.txt”, ‘wb’) { |f| 10.kilobytes.times { f.write BUFFER } }

Kind regards

robert