listing a directory by size

[April]

For the following program, found somethings seem not seen before, one
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]

Another way of writing
glob(*);

ITYM: glob '*';


John

 

[Jürgen Exner]

ITYM: glob '*';

Hmmm, yes.

jue

 

[xhoster]

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 (e-mail address removed):

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

 

[xhoster]

Quoth (e-mail address removed):

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 .*

Xho

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[Jürgen Exner]

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]

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).


%i is a hash. $i{$f} is a hash lookup.


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.



John