You guys are the best...thx

The above assumes big-endian byteorder. For little-endian use "V" instead
of "N". Or just use "L" when the file has the same byteorder as the
machine you are running this script on.

Btw, the hex() above is probably wrong. hex() converts a string into a
numeric value by intepreting it as hexadecimal. Essentially, you do it
twice resulting in:

$hex = 0xff == 255 => hex(255) == 597

Whereas:

$hex = "0xff" => hex($hex) == 255

Tassilo
--
$_=q#",}])!JAPH!qq(tsuJ[{@"tnirp}3..0}_$;//::niam/s~=)]3[))_$-3(rellac(=_$({
pam{rekcahbus})(rekcah{lrePbus})(lreP{rehtonabus})!JAPH!qq(rehtona{tsuJbus#;
$_=reverse,s+(?<=sub).+q#q!'"qq.t$&."'!#+sexisexiixesixeseg;y~n~~dddd;eval

woops, you are correct. the 'hex $hex' assumes it is passed as a string.
other than that it works as expected on both my Win2k (intel, little endian)
and Solaris (sparc, big endian). The bin result is returned in big endian on
both machines, so one would have to be cognizant that the result is not
returned in the native format for little endian machines. And yes it depends
on how the file is formatted. so we can make some adjustments:

--
$hex = '0xff'; #passed as a string
$bin = unpack("B32", pack("N", hex $hex));
print $bin;

---
$hex = 0xff;
$bin = unpack("B32", pack("N", $hex)); #passed as a hex number
print $bin;

----
# print in correct order for little endian machines
$hex = '0xff';
$bin = unpack("B32", pack("L", hex $hex));
print $bin;

-----

Thanks Tassilo !

That's why I asked what he meant. The absolut simpleest would be:

#!/usr/bin/perl -w

use strict;
use CGI qw(header);
use File::Slurp;

pritn header();
print read_file("./index.html");

Pretty pointless unless you did something with the file:

my $file = read_file("./index.html");

$file =~ s/Joemama/Monkey/g;
print $file;

Now what I assumed he probably meant was:

print header();
if(whatever) { process formand output html results )
else { print formhtml }

Whatever.

Dan

Net::SSH::Perl relies on a number of modules for the different cipher types, DES as well. The local SSH client has nothing to do with the module as it handles the whole process internally rather than shelling out or using an external client. If it is telling you all you have available is RC4 then that is probably correct and you need to install the other modules.

If my records are correct you should only need Crypt::DES to add DES support. You might try installing using CPAN rather than the SUSE package (if that is how you installed it) so that you are prompted for the compatibilities you want in Net::SSH::Perl and to make sure the dependencies are satisfied as there are a lot of them (if you installed from CPAN did it not prompt you?). I will attach the dependency chart I generated before (though it may not be complete, for all ciphers, etc.) (There is also a bug in Math::PARI/pari if you have a long running application that causes a memory leak that generates weird results - it takes about 2 hours to generate running about 30 commands every minute)

Does this help?

http://danconia.org

Dependency list:

- Net::SSH::Perl (requires
- Digest::HMAC_MD5 (requires Digest::MD5, Digest::SHA1)
- Digest::MD5 (requires N/A)
- Digest::SHA1 (requires N/A)
- Crypt::DSA (requires Crypt::Random, Math::Pari, Digest::SHA1, prefers Data::Buffer
for (ssh2))
- Crypt::Random (requires Math::Pari, Class::Loader)
- Class::Loader (requires N/A)
- Math::Pari (requires pari C libraries)
- Math::Pari (requires pari C libraries)
- Digest::SHA1 (requires N/A)
- Data::Buffer (requires N/A)
- Crypt::RSA (requires Digest::MD2, Convert::ASCII::Armour, Crypt::Primes, Tie::EncryptedHash, Crypt::Blowfish, Sort::Versions)
- Digest::MD2 (requires N/A)
- Convert::ASCII::Armour (requires Digest::MD5, Compress::Zlib)
- Digest::MD5 (requires N/A)
- Compress::Zlib (requires N/A)
- Crypt::Primes (requires Crypt::Random, Math::Pari)
- Crypt::Random (requires Math::Pari, Class::Loader)
- Class::Loader (requires N/A)
- Math::Pari (requires pari C libraries)
- Math::Pari (requires pari C libraries)
- Tie::EncryptedHash (requires Crypt::Blowfish, Crypt::CBC, Crypt::DES)
- Crypt::Blowfish (requires N/A)
- Crypt::CBC (requires Digest::MD5, Crypt::Rijndael)
- Digest::MD5 (requires N/A)
- Crypt::Rijndael (requires N/A)
- Crypt::DES (requires N/A, prefers Crypt::CBC)
- Crypt::CBC (requires Digest::MD5, Crypt::Rijndael)
- Digest::MD5 (requires N/A)
- Crypt::Rijndael (requires N/A)
- Crypt::Blowfish (requires N/A)
- Sort::Versions (requires N/A)
- Convert::PEM (requires Digest::MD5, Convert::ASN1, Crypt::DES_EDE3)
- Digest::MD5 (requires N/A)
- Convert::ASN1 (requires N/A)
- Crypt::DES_EDE3 (requires Crypt::DES)
- Crypt::DES (requires N/A, prefers Crypt::CBC)
- Crypt::CBC (requires Digest::MD5, Crypt::Rijndael)
- Digest::MD5 (requires N/A)
- Crypt::Rijndael (requires N/A)
- Crypt::DH (requires Crypt::Random, Math::Pari)
- Crypt::Random (requires Math::Pari, Class::Loader)
- Class::Loader (requires N/A)
- Math::Pari (requires pari C libraries)
- Math::Pari (requires pari C libraries)
- Math::Pari (requires pari C libraries)
- Crypt::DES (requires N/A, prefers Crypt::CBC)
- Digest::SHA1 (requires N/A)
? Math::GMP (requires gmp C libraries) (ssh1 only)

my $name = 'Anthony Bob';
$name =~ tr/ //d; # remove the space
my @letters = split //, $name;

print "$_n" foreach @letters;

Hope that helps.

James

Howdy

It's cuz Perl rocks!!

Rather than using split and grep, you can use a capturing regex with /g in
list context to return a list of matches:

@letters = uc($word) =~ /([A-Z])/g;

depends on how you declare (global or lexical), you might go to the symbol
table and ask for a certain type of variables (array, hash, scalar, etc)
and update their values. the following assumes that you declare your
variables as global with 'our' and update the third element (to have the
value of 99) of all arrays whose name begines with 'xyz':

#!/usr/bin/perl -w
use strict;

#--
#-- the following 3 arrays are declared with 'our' which makes
#-- them global and thus visible in the symbol table. the third
#-- element of those arrays will be updated to have the value of 99
#--
our @xyz_var1 = 1 .. 5;
our @xyz_var2 = 2 .. 6;
our @xyz_change_me = 12 .. 16;

#--
#-- the following is not updated:
#--
#-- @dont_change_me: because it doesn't start with xyz
#-- %xyz_dont_change_me: because it's a hash, not array
#-- $xyz_dont_change_me: because it's a sclar, not array
#-- @xzy_not_global: because it's declared with 'my' which makes it lexical
#--
our @dont_change_me = 7 .. 11;
our %xyz_dont_change_me = 50 .. 53;
our $xyz_dont_change_me = 100;
my @xzy_not_global = 17 .. 21;

#--
#-- this asks the symbol table for all globol variables declared so far
#-- and update the array's 3rd element to 99
#--
$::{$_}->[2] = 99 for(grep {/^xyz/} keys %::);

#--
#-- demo to show their values are indeed changed
#--
print join(" ",@xyz_var1),"n";
print join(" ",@xyz_var2),"n";
print join(" ",@xyz_change_me),"nn";

#--
#-- demo to show that this is not changed
#--
print join(" ",@dont_change_me),"n";
print join(" ",@xzy_not_global),"n";

__END__

prints:

1 2 99 4 5
2 3 99 5 6
12 13 99 15 16

7 8 9 10 11
17 18 19 20 21

generally, this is a poor approach especially if you are new to Perl. you
might accidentally change something that you are not intended to change.
other disadvantages include:

* it's slow because it walks the entire symbol table each time it's called.
you can improve this by caching the variables in a hash but you must be
careful that you don't declare more arrays after you cache them because the
cache version won't see those.

* it's dangerous because we might change something that you don't really
want to change. this is especially important if you are new to Perl.

* if your arrays are declared with 'my', they won't be changed at all.

david

Hello,

my $text = ' Anthony Bob ';

my @letters = $text =~ /[[:alpha:]]/g;

print "$_n" for @letters;



John
--
use Perl;
program
fulfillment

You may want to check out the MONO project:

http://go-mono.org/

http://danconia.org

_
This message and any attachments are intended only for the use of the addressee and
may contain information that is privileged and confidential. If the reader of the
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intended recipient, you are hereby notified that any dissemination of this
communication is strictly prohibited. If you have received this communication in
error, please notify us immediately by e-mail and delete the message and any
attachments from your system.

I never knew you could leave the parens off in a case like this. I just went
and looked it up. Neat!

This works too (at least, works for me):

my $text='Anthony Bob';
my @letters=split(//, $text);
print(join("n", @letters));

--
Bernhard van Staveren - madcat(at)ghostfield.com
GhostField Internet - http://www.ghostfield.com/
"A witty saying proves nothing, but damn it's funny!" - me, 1998

What you seem to be doing is not very clear. Why are you running this loop
while (@array = $query->fetchrow_array ) {
($field1, $field2, $field3, $field4, $field5, $field6, $field7, $field8,
$field9, $field10,
$field11, $field12, $field13, $field14, $field15, $field16, $field17,
$field18) = @array;}

If you just want the last transaction id change the query
to "select max($field1) from cash where $x = $y ";

This will give you the last transaction id directly


BTW
1) Have you considered using an autoincrement field
2) Do not connect to the database in every function of yours .
Make one connection in the beginning and pass the handle to all functions.
3) And when you post a reply to a newsgroup post your reply *at the
bottom* avoid top posting

Ram

I've sussed it, I hand an empty pair (''=>'') in the hash from when I was
keying in the key/value pairs.
--
Gary Stainburn

This email does not contain private or confidential material as it
may be snooped on by interested government parties for unknown
and undisclosed purposes - Regulation of Investigatory Powers Act, 2000

in more than one function...

something wrong. You should only select exactly what you want from a
database rather than "just give me it all and I'll figure it out later".
Especially because--judging from the loop below--you don't appear to use
anything in the db except the first field, but also because this method
doesn't take into account changing database structure. Ramprasad
suggested "select max($field1) from cash where $x = $y " but keep in
mind you should do this using placeholders where any user input is
involved to protect yourself from SQL injection attacks. =]

loop that's iterating through database query results!
Move finish and disconnect out of the loop.

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That would depend on how you plan to measure the speed. Are you downloading
a file and calulating the speed like "bandwidth testing" places do?

Are you keeping track of packets in a datatbase, interfacing a QOS system, etc?

The method you use to figure that will decide how you go about doing it with Perl.

What tools are they? Maybe we can find a way to do what they do in Perl.

Okay, so far the only thing you need to do is read the documentation
for spammassassin. There's a few ways to do it. I personally use
MH-mail, procmail, postfix, and fetchmail. Fetchmail picks up the
mail, forwards it to the SMTP server on the box, checks for viruses
(yes, you CAN check mail for viruses on Linux - not that it would harm
anything - but my wife enjoys Windows, so I have to keep her safe and
get her mail - then she grabs the mail off my system ... where was I
.... oh, ya), then it goes through procmail, which has a "recipe" to
filter it using spamassassin (to pick up "stray" spam - read on). So
far, the only thing Perl is spamassassin.

Well, this again is not Perl, but you can set fetchmail NOT to mark
messages as being read when you get them. Not exactly what you
wanted, but to send mail BACK to your webmail account seems redundent
- but that's my opinion and the fact that I'm spoilled by my ISP
(which does use spamassassin). However, if you want to 'roll your
own' solution, there are several Perl modules to aid you in this task.
Check http://search.cpan.org/

Just a side note: if you are responsible about testing, you're going
to need to set up a mail server anyway. I can speak from experience
that it's a bad idea to use a script (or fetchmail for that matter)
and not test it in a controled environment first. You end up lossing
mail if you don't test first ;)

IMHO, use the tools on your system. They are proven, maintained, and
work. That's not a reflection of any Perl scripts you may find/write
- but why re-invent the wheel? Unless that what's you want to do. I
mean, why write say, a web server in Perl, unless you think you can do
better than Apache -or- want the experience. HOWEVER, I'd ditch
sendmail and start using postfix ... but here again, not Perl and just
my opinion.

If you decide to 'roll your own', you're going to have a monumental
task ahead of you.

HTH

Jim

http://search.cpan.org/dist/IO-Tee/
http://jenda.krynicky.cz/#Local::TeeOutput

HTH, Jenda
===== [Email Removed] === http://Jenda.Krynicky.cz =====
When it comes to wine, women and song, wizards are allowed
to get drunk and croon as much as they like.
-- Terry Pratchett in Sourcery

Methods are the easy part:

our @ISA = qw(ClassOne ClassTwo Etc);

Perl doesn't really provide a method for instance variable inheritance
(even for single inheritance), but you can generally roll your own easy
enough. Here's one possible method:

sub new {
my $class = shift;
my $object = { };
$object = $_->new(%$object) foreach @ISA;
# class specific initialization here...
return bless $object, ref($class) || $class;
}

This is heavily dependent on the classes you are trying to inherit from
though, so you may have to get a little more creative. Watch for
parent classes stomping on each others' member data with this too, it
could happen.

If you need something more robust, you might create instances of the
parent classes as store them internally as private instance data. You
could then basically use your class as a proxy for them, passing what
is needed, to who, when. You probably need to do a little more
subroutine work for this method, though I imagine most of them would
just be one-liners calling the appropriate parent method on the
internal object. A good AUTOLOAD with a little can() magic should even
get you around this, if you're Lazy.

Well, hopefully that at least gives you a couple of ideas. Good luck.

James

Hello,

You should _ALWAYS_ verify that your files were opened correctly:

open( READFILE1, $writefilename ) or die "Cannot open $writefilename:
$!";
open( WRITEFILE1, ">>cdf.txt" ) or die "Cannot open cdf.txt: $!";

You are telling split() to split on zero or more whitespace which is the
same as splitting the string into individual characters and removing the
whitespace.

$ perl -le'print ">$_<" for split /s*/, "one two"'

According to your code, this should do the same thing:

for ( @array ) {
s/Celld=//i;
s/s+//g;
print WRITEFILE1;
}

John
--
use Perl;
program
fulfillment

This aint entirely true. You can use File::Copy to copy files to
remote shares (Windows Networking), remote drives mounted via NFS ,
.... basicaly anything that the OS allows you to treat like a local
disk.

Jenda
===== [Email Removed] === http://Jenda.Krynicky.cz =====
When it comes to wine, women and song, wizards are allowed
to get drunk and croon as much as they like.
-- Terry Pratchett in Sourcery

Hmmm... my guess is the $1. The `` interpolates. You need to escape the
dollar sign with a backslash... otherwise it puts the value of $1 into your
command before executing it.

You might want to use strict, it would have caught that.

Rob

-----Original Message-----
From: Bill Akins [mailto:[Email Removed]]
Sent: Thursday, August 21, 2003 2:01 PM
To: [Email Removed]
Subject: Split on white space from `command` return?


Hi!

I would like to grab the first column (variable width) of data in each
line that will be returned from an external command.
I tried @PSARRAY = `command | grep bf1`; and got just the lines with
data I wanted. The returned data looks like this:

EHCFS001 Booted Down bf1/p20 Windows/MU Yes,Opt,0 12:55:29
VMDFS Booted Up bf1/p14 VM25AS21e16/MU Yes,Opt,0
12:52:12
ORA_1 Booted Up bf1/p18 VM25AS21e16/MU Yes,Opt,0
12:56:25
ps3 Booted Up bf1/p3 custom/MU Yes,Opt,0 12:51:56
ps4 Booted Up bf1/p4 custom/MU Yes,Opt,0 12:51:42
ps5 Booted Up bf1/p5 custom/MU Yes,Opt,0 12:51:22

I need to capture just EHCFS001, VMDFS, ORA_1, PS3, PS4 and PS5 in a
var, array, hash, whatever and I don't care about any of the other data.
A variable would be preferable over array, I think.

I then tried @PSARRAY = `command | grep bf1 | awk -F " " '{print $1}'`
but got the same exact results. Anyone know why it didn't like the awk
command or just decided to ignore it?
If I run command | grep bf1 | awk -F " " '{print $1}' on the command
line I get exactly what I need, why doesn't this work during an external
call?

Running on Linux, Perl 5.6.1

Thanks all.



Bill Akins
SSS III
Emory Healthcare
( - Office
12674 - PIC
[Email Removed]

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command | grep bf1 | cut -d ' ' -f 1

....Or just use Perl

# untested
my @var = map {/^w+/;$&} grep {/bf1/} `command`;

Hmmm... my guess is the $1. The `` interpolates. You need to escape the
dollar sign with a backslash... otherwise it puts the value of $1 into your
command before executing it.

You might want to use strict, it would have caught that.

Rob

-----Original Message-----
From: Bill Akins [mailto:[Email Removed]]
Sent: Thursday, August 21, 2003 2:01 PM
To: [Email Removed]
Subject: Split on white space from `command` return?


Hi!

I would like to grab the first column (variable width) of data in each
line that will be returned from an external command.
I tried @PSARRAY = `command | grep bf1`; and got just the lines with
data I wanted. The returned data looks like this:

EHCFS001 Booted Down bf1/p20 Windows/MU Yes,Opt,0 12:55:29
VMDFS Booted Up bf1/p14 VM25AS21e16/MU Yes,Opt,0
12:52:12
ORA_1 Booted Up bf1/p18 VM25AS21e16/MU Yes,Opt,0
12:56:25
ps3 Booted Up bf1/p3 custom/MU Yes,Opt,0 12:51:56
ps4 Booted Up bf1/p4 custom/MU Yes,Opt,0 12:51:42
ps5 Booted Up bf1/p5 custom/MU Yes,Opt,0 12:51:22

I need to capture just EHCFS001, VMDFS, ORA_1, PS3, PS4 and PS5 in a
var, array, hash, whatever and I don't care about any of the other data.
A variable would be preferable over array, I think.

I then tried @PSARRAY = `command | grep bf1 | awk -F " " '{print $1}'`
but got the same exact results. Anyone know why it didn't like the awk
command or just decided to ignore it?
If I run command | grep bf1 | awk -F " " '{print $1}' on the command
line I get exactly what I need, why doesn't this work during an external
call?

Running on Linux, Perl 5.6.1

Thanks all.



Bill Akins
SSS III
Emory Healthcare
( - Office
12674 - PIC
[Email Removed]

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For additional commands, e-mail: [Email Removed]

use qx'' around your command (but then you have to protect the single quotes

But there's no need for the awk or grep, since perl has functions to handle
that kind of thing. Try something like:

@PSARRAY = map +(split)[0], grep /bf1/, `command`;

As you have observed, printf returns true if it worked (or false if it
didn't.) You
could do it like this:

my ( $oldest ) = sort { (-M $b) <=> (-M $a) } glob "v:*";

unlink $oldest or warn "Cannot delete $oldest: $!";


Or like this:

my $oldest = ( sort { (-M $b) <=> (-M $a) } glob "v:*" )[ 0 ];

unlink $oldest or warn "Cannot delete $oldest: $!";


But both of those methods use an inefficient sort because you are
stat()ing each
file more than once. Here are two methods that only stat()s each file
once.

my ( $oldest ) = map $_->[ 0 ],
sort { $b->[ 1 ] <=> $a->[ 1 ] }
map [ $_, -M ],
glob "v:*";

unlink $oldest or warn "Cannot delete $oldest: $!";


This is the most efficient as it only stat()s each file once and it
doesn't have to sort.

my $oldest = [ '', 0 ];
for my $file ( glob "v:*" ) {
my $date = -M $file;
$oldest = [ $file, $date ] if $oldest->[ 1 ] < $date;
}

unlink $oldest->[ 0 ] or warn "Cannot delete $oldest->[0]: $!";



John
--
use Perl;
program
fulfillment

$ENV{FLEE} = 'FLEE';
^remember about the '$' sigil.

See perlvar(1) manpage:
http://www.perldoc.com/perl5.8.0/pod/perlvar.html#%25ENV
"The hash %ENV contains your current environment. Setting a value in ENV
changes the environment for any child processes you subsequently fork()
off."

"Perl programming is an *empirical* science" after all, so you can ckeck
out if it changes the real environment:

#!/usr/bin/perl -wl
print "Old PATH: $ENV{PATH}";
$ENV{PATH} .= ':/ABCDEF';
print "%ENV PATH: $ENV{PATH}";
$/ = "";
open $env, '<', "/proc/$$/environ" or die $!;
while (<$env>) {
print "Real PATH: $1" if /^PATH=(.*)/;
}
close $env;

And it doesn't. %ENV is just a normal hash, it's not tied or anything.
But if it is your only way of reading your environment (and even
POSIX::getenv() just returns the %ENV elements) then it doesn't really
matter. I'm not quite sure if that answers your question though.

This won't work, because it will change the environment of the child
shell processes, which doesn't affect the environment of their parent,
i.e. your program process.

Try:

print `echo $FLEE`;
print `echo $FLAA`;

You need to print the value returned by backticks and you need the
backslach to escape the $ sigil, because otherwise perl would
interpolate its $FLEE variable there. Or instead of backticks, just use
system():

system 'echo $FLEE';

You don't have to escape $ in single quotes and system() doesn't capture
the output of your command, so it's just printed to stdout.

-zsdc.

Mildly tested (and ugly) but how 'bout replacing this with something to
the effect of:

foreach (sort { (stat("//sco1/pm6/reports/$b"))[9] <=>
(stat("//sco1/pm6/reports/$a"))[9] } readdir (DH)) {
:
}

Perl isn't doing anything but calling the OS's underlying readdir(2) call.
You shouldn't make any assumptions about the order in which readdir()
returns files. If you need them in some particular order, read them and then
sort them.

Files are not stored on the file system in any predefined order. If
they appear to be in some order then that is just a coincidence. If you
want the file names in a certain order then you will have to sort them
yourself.

my $dir = '//sco1/pm6/reports';

opendir DH, $dir or die "Can not open $dir: $!";

my @files = map $_->[0],
sort { $b->[1] <=> $a->[1] }
map [ $_, -M "$dir/$_" ],
grep /^Sj/,
readdir DH;

closedir DH;



John
--
use Perl;
program
fulfillment

No, it usually tells the (*nix) shell what program has to start
- in this case /usr/bin/perl - and with what kind of arguments - -w -.
The shell then passes all lines but this first one as STDIN to the called
program, in this case perl.

Well, the windows shell (dos box) doesn't interpret the shebang line
#!...,
so it doesn't play that important role whether
/usr/bin/perl is written or c:/perl.
However I personally would prefer to write
#!/usr/bin/perl
even on windows as it doesn't matter for windows,
but is more likely to run also on *nix machines

Yes, allthough windows itself doesn't interpret this line,
perl still scans it.
E.g. it looks for the -w switch or any other possible arguments on the
#! line.

(I believe, perl expects also that the substring "perl" is in the #! line
for interpreting, otherwise it assumes the #... line is really only a
commentar)

Why? Does your program something very operating system specific?
Unless it is an extra work, it's always a good habit to work with
standards and intercompability.
You can't loose anything but perhaps winning in one day some time.


Greetings,
Janek

Exactly. Moreover, you should never assume the order of anything
returned by an iterator like 'readdir' unless it is documented.

The nicest general solution I can think of is to use 'File::Find'
with your 'wanted' routine set to push $File::Find::name onto an
array @files. Then you can just do

@files = sort { -M $A <=> -M $B} @files;

(People will then tell you to use Randalian Transform ;-)
but then I will tell you to worry only if your code is too slow.)

Cheers,

Rob

It seems that you attack this from the wrong angle. Everything that is fast enough to solve your problem in a given time is fast enough. I.e. If you don't have any requirements towards how fast you have to sort the data means that your program is fast enough.

The question you are asking is about perl optimization... which is mostly answered with the following answer: DON'T... STOP... DON'T EVEN THINK ABOUT IT.

Various reasons behind all of this is that people don't know which part they have to optimize. Even though their are modules that will help you to find out the lines of code that take the longest.

Take a look at Devel::DProf which is a Perl code profiler.

Though always remember: Optimization takes time, increases complexity, adds bugs, wrecks encapsulation, reduces readability and last but not least makes your code unmaintainable.

thanks
/oliver/

I guess it ain't really not one.

Time depends on the time to connect to FTP.
However, the time is always independent of the programming language,
thus neglioabable to your problem.

Again independent of the programming language.

Mostly independent of the programming language,
however you can always use the zip and unzip programs if a solution in a
specific language, e.g. a pure Perl solution might be slower.

So the time depends only on the size of files.

Do you need to parse them or do you need to sort them?
However, parsing is something Perl is very good in.
Thus you can simply obtain, a Perlish solution is the quickest way,
so you also don't need to know how quick Perl is.

Sorting is something different as there might be very quick c solution
specialised to sorting on hard disks.

But that depends also on the size of the files.
I assume simply 30_000 lines of 100 columns each
=> 3_000_000 bytes = 3 MB.
3 MB would be nowadays so less that it Perl's memory wasting wouldn't
create problems.
Unless memory problems, common sort routines are very quick in all
languages, also to Perl.

Depends on the time of the database.

Depends on the check routine, but I assume it is also language independent.

It's always possible, you'll only need a computer that is expensive
enough. However, if my guess of 3 MB is right, it should be easy with
nowadays desktop pcs in every language.

http://www.google.com/search?q=benchmark+p...mming+languages


Greetings,
Janek

Benchmark between languages are - at the best of times - misleading.
They tend to contrive some seemingly common problems and compare their
implementations in different languages. Not even the p5-porters have so
far managed to come up with a reliable benchmark for comparing perl with
perl (perlbench gives nice tables but real-world programs often seem to
contradict these tables).

But as it can be seen in this thread, the problem wont be solved using
pure-Perl. Database access usually happens via modules written in C.
Therefore, a program making heavy use of an SQL database written in pure C
and one written in Perl will yield very comparable results.

I remember the longest-repeated-substring problem that was discussed
some months ago on MJD's quiz-of-the-week mailinglist. A reasonably fast
Perl solution looked very un-Perlish (doing it all with raw index() and
substr() operations for the sake of speed) and thus was easy to
translate to XS. The C implementation was faster to an degree of 5%, at
most. But sometimes it was even slower.

On the other hand, Octave for instance was written in C and Fortran. If
you take this and compare it with an implementation in Perl (if it
existed), it will surely make Perl look very poor.

So only for very sanitized ('pure') problems you'll be able to predice
which implementation will likely be fastest. The problem of the OP is no
such case. First you have the overhead of the FTP transaction,
afterwards unzipping that can either be done the slow way (Archive::Zip)
or in an intelligent way (when speed matters) through PerlIO::gzip or
even an external unzipper.

The only thing that really might make look one language more appropriate
than the other is the sorting. But again, precise figures can't be given
since Perl's sort is either very performant (when using one of the
optimized default routines) or painfully slow (with a complicated custom
comparison-routine).

Then a little bit I/O is carried out. Again, only little significance to
the language (they all are somewhat C-based). Yet, Perl is known to do
I/O a little better than most competitors. Eventually, database-access.
That's no concern when using one of the C-implementations in the DBD::
namespace.

Conclusion: most common languages should be able to do that in
reasonable time. They are no different than Perl in that they interface
with C code for tasks like working with compressed files, I/O and
databases. Unless of course you do in PROLOG or some other truely exotic
language.

Tassilo
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