listing a directory by size
April
is the input <*>, everything and anything? Another is the usage
$i{$f} or $i{$b}, etc., not sure what that means?
foreach $f (<*>) ( $i{$f} = -S $f };
foreach $k (sort{ $i{$b} <=> $i${a} } keys %i}
{ printf "%8d %s\n", $i{$k}, $k }
Any guru can explain? Thanks!
Jürgen Exner
>For the following program, found somethings seem not seen before, one
>is the input <*>, everything and anything?
Another way of writing
glob(*);
> Another is the usage
>$i{$f} or $i{$b}, etc., not sure what that means?
See
perldoc perldata
and look for hashes. It is retrieving the value of %i for the key that
has the value of $f resp. $b.
jue
John W. Krahn
> April <xiaoxi...@yahoo.com> wrote:
>> For the following program, found somethings seem not seen before, one
>> is the input <*>, everything and anything?
>
> Another way of writing
> glob(*);
ITYM: glob '*';
John
--
Perl isn't a toolbox, but a small machine shop where you
can special-order certain sorts of tools at low cost and
in short order. -- Larry Wall
Jürgen Exner
>Jürgen Exner wrote:
>> April <xiaoxi...@yahoo.com> wrote:
>>> For the following program, found somethings seem not seen before, one
>>> is the input <*>, everything and anything?
>>
>> Another way of writing
>> glob(*);
>
>ITYM: glob '*';
Hmmm, yes.
jue
xho...@gmail.com
> For the following program, found somethings seem not seen before, one
> is the input <*>, everything and anything?
Yes. There is nothing special about it, it is just the "file glob" version
of the diamond operator, and just happens to have an argument of '*', which
does indeed mean all non-hidden files (in the current directory).
> Another is the usage
> $i{$f} or $i{$b}, etc., not sure what that means?
%i is a hash. $i{$f} is a hash lookup.
> foreach $f (<*>) ( $i{$f} = -S $f };
This is storing each file in the hash %i, with the hash key being the
file name and hash value being the file size.
Xho
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Ben Morrow
Quoth xho...@gmail.com:
> April <xiaoxi...@yahoo.com> wrote:
> > For the following program, found somethings seem not seen before, one
> > is the input <*>, everything and anything?
>
> Yes. There is nothing special about it, it is just the "file glob" version
> of the diamond operator, and just happens to have an argument of '*', which
> does indeed mean all non-hidden files (in the current directory).
So, not everything and anything. Specifically, it omits all files with
names beginning with '.', even on OSs where that is not a convention for
'hidden file'. It ignores e.g. DOS 'hidden file' attributes.
Ben
--
Many users now operate their own computers day in and day out on various
applications without ever writing a program. Indeed, many of these users
cannot write new programs for their machines...
-- F.P. Brooks, 'No Silver Bullet', 1987 [b...@morrow.me.uk]
xho...@gmail.com
> Quoth xho...@gmail.com:
> > April <xiaoxi...@yahoo.com> wrote:
> > > For the following program, found somethings seem not seen before, one
> > > is the input <*>, everything and anything?
> >
> > Yes. There is nothing special about it, it is just the "file glob"
> > version of the diamond operator, and just happens to have an argument
> > of '*', which does indeed mean all non-hidden files (in the current
> > directory).
>
> So, not everything and anything. Specifically, it omits all files with
> names beginning with '.', even on OSs where that is not a convention for
> 'hidden file'. It ignores e.g. DOS 'hidden file' attributes.
I did not know that. I knew it used the Unix interpretation of "*.*"
rather DOS's, but I didn't know it also used Unix's method of hiddenness.
Maybe 'Why doesn't glob("*.*") get all the files?' should be changed
to make that clearer. I don't exactly how, maybe from:
You'll need "glob("*")" to get all (non-hidden) files
to
You'll need "glob("*")" to get all (non-dot) files
That doesn't sound all that clear either.
Maybe adding ", including the Unix notion of filenames starting with a
dot being hidden." after:
Because even on non-Unix ports, Perl's glob function follows standard Unix
globbing semantics
Anyway, I found it misleading as-is because I assumed the semantics being
discussed were only those concerning *.*, not also those concerning .*
Jürgen Exner
>Ben Morrow <b...@morrow.me.uk> wrote:
>> So, not everything and anything. Specifically, it omits all files with
>> names beginning with '.', even on OSs where that is not a convention for
>> 'hidden file'. It ignores e.g. DOS 'hidden file' attributes.
>
>I did not know that. I knew it used the Unix interpretation of "*.*"
>rather DOS's, but I didn't know it also used Unix's method of hiddenness.
It's documented but well hidden in perldoc -f glob:
glob Returns the value of EXPR with filename expansions such as
the standard Unix shell /bin/csh would do. [...]
I guess you just have to know what /bin/csh would do.
>Anyway, I found it misleading as-is because I assumed the semantics being
>discussed were only those concerning *.*, not also those concerning .*
Another good point.
jue
John W. Krahn
> April <xiaoxi...@yahoo.com> wrote:
>> For the following program, found somethings seem not seen before, one
>> is the input <*>, everything and anything?
>
> Yes. There is nothing special about it, it is just the "file glob" version
> of the diamond operator, and just happens to have an argument of '*', which
> does indeed mean all non-hidden files (in the current directory).
>
>> Another is the usage
>> $i{$f} or $i{$b}, etc., not sure what that means?
>
> %i is a hash. $i{$f} is a hash lookup.
>
>> foreach $f (<*>) ( $i{$f} = -S $f };
>
> This is storing each file in the hash %i, with the hash key being the
> file name and hash value being the file size.
Actually the value is true or false depending on whether $f is a socket
or not.