If you used print it will be displayed correctly:

C:\test>dir huge.3.5GB
2008-11-25  09:29     3,758,096,387 huge.3.5GB
               1 File(s)  3,758,096,387 bytes

C:\test>perl -wle"print -s $ARGV[ 0 ]" huge.3.5GB
3758096387
[download]

You'll only see the problem if you use printf with %d:

C:\test>perl -wle"printf qq[%d\n], -s $ARGV[ 0 ]" huge.3.5GB
-536870909
[download]

And you can avoid that by using %f or %u instead:

C:\test>perl -wle"printf qq[%.f\n], -s $ARGV[ 0 ]" huge.3.5GB
3758096387

C:\test>perl -wle"printf qq[%u\n], -s $ARGV[ 0 ]" huge.3.5GB
3758096387
[download]

However, %u is limited to 2**32-1 (a limitation by design that %.f doesn't have):

C:\test>dir huge.6.0GB
2008-11-25  09:40     6,442,450,947 huge.6.0GB
               1 File(s)  6,442,450,947 bytes

C:\test>perl -wle"printf qq[%u\n], -s $ARGV[ 0 ]" huge.6.0GB
4294967295

C:\test>perl -wle"printf qq[%.f\n], -s $ARGV[ 0 ]" huge.6.0GB
6442450947
[download]

This "problem" is nothing to do with filesizes (or win32 per se), but rather that printf %d treats numbers as signed integers, so values between 2**31 and 2**32 are displayed as negative. They are held correctly internally.

but I didn't use printf yet...
I use print in your way.

but I didn't use printf yet... I use print in your way.

Show us the code!

---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

Update: please ignore, read BrowserUk's explanation below instead. In my humble opinion that's a bug in perl, so please file a bug report for that.

It sounds like a typical integer overflow.

Maybe a workaround is to add 2**31 to negative sizes, but it's not a nice "solution" at all.

As long as the perl in question is built with uselargefiles=define, (which means all AS perls and most others by default for at least the last 6+ years, probably longer), then perl quite happily, accurately and correctly deals with files up to at least 9e15 (~9,000 Terabytes).

Also, I don't think it's even possible to get Win32::DirSize to give the size of a single file--unless it happened to be the only file in the directory--but in any case, it (and all it's conversion functions/methods) are totally unneccessary unless you have access to a filesystem that can store a single file > 9e15. (Is that even possible given current disk technology?)

---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

Simple solution: upgrade from 5.6.1 to some later build.

More complicated solution: Rebuild 5.6.1 having defined uselargefiles.

---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."