[31270] in Perl-Users-Digest
Perl-Users Digest, Issue: 2515 Volume: 11
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Sun Jul 12 03:09:43 2009
Date: Sun, 12 Jul 2009 00:09:07 -0700 (PDT)
From: Perl-Users Digest <Perl-Users-Request@ruby.OCE.ORST.EDU>
To: Perl-Users@ruby.OCE.ORST.EDU (Perl-Users Digest)
Perl-Users Digest Sun, 12 Jul 2009 Volume: 11 Number: 2515
Today's topics:
[OT] Re: formatting a number of elsif statements <m@rtij.nl.invlalid>
Re: [OT] Re: formatting a number of elsif statements sln@netherlands.com
Re: Calling 'C' routines from perl. <ralph.malph@altavista.com>
Re: FAQ 4.28 How do I change the Nth occurrence of some <brian.d.foy@gmail.com>
ImageShack Hacked - Popular Image Hosting Website Vanda <reid@tardis-db.co.uk>
Re: Perl Fails To List All The Multiple Matches In The <m@rtij.nl.invlalid>
Re: Perl Fails To List All The Multiple Matches In The <jurgenex@hotmail.com>
Re: To extract file name only from a file sln@netherlands.com
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Fri, 10 Jul 2009 22:32:35 +0200
From: Martijn Lievaart <m@rtij.nl.invlalid>
Subject: [OT] Re: formatting a number of elsif statements
Message-Id: <34lki6-9mn.ln1@news.rtij.nl>
On Thu, 09 Jul 2009 15:18:50 -0700, sln wrote:
> On Thu, 09 Jul 2009 14:39:54 -0700, sln@netherlands.com wrote:
>
>>On Thu, 9 Jul 2009 07:18:09 +0200, Martijn Lievaart <m@rtij.nl.invlalid>
>>wrote:
>>
>>>On Mon, 06 Jul 2009 13:32:51 -0700, sln wrote:
>>>
>>>>>Another reason is that it can often be implemented using a branch
>>>>>table.
> <snip>
>
> It cannot be! Comparisons on each case must be made, there is no single
> leaf.
It's rather simple, something like:
switch (x) {
case 1:
f1();
break;
case 2:
f2();
break;
.
.
.
case <n>:
f<n>;
break;
}
might be implemented (in pseudo assembler)
.data
label branchtable
Lcont
L1
L2
.
.
.
L<n>
.code
; value is in accumulator X
CMP X,<n>
JGT Lcont
JMP branchtable[x]
L1:
call f1
JMP Lcont
L2:
call f2
JMP Lcont
.
.
.
L<n>:
CALL f<n>
Lcont:
Again, this is pretty basic stuff, consult a good book on compilers.
M4
------------------------------
Date: Sat, 11 Jul 2009 16:29:59 -0700
From: sln@netherlands.com
Subject: Re: [OT] Re: formatting a number of elsif statements
Message-Id: <b16i5517m6rb7t08so6vm73u14dct0iqg8@4ax.com>
On Fri, 10 Jul 2009 22:32:35 +0200, Martijn Lievaart <m@rtij.nl.invlalid> wrote:
>On Thu, 09 Jul 2009 15:18:50 -0700, sln wrote:
>
>> On Thu, 09 Jul 2009 14:39:54 -0700, sln@netherlands.com wrote:
>>
>>>On Thu, 9 Jul 2009 07:18:09 +0200, Martijn Lievaart <m@rtij.nl.invlalid>
>>>wrote:
>>>
>>>>On Mon, 06 Jul 2009 13:32:51 -0700, sln wrote:
>>>>
>>>>>>Another reason is that it can often be implemented using a branch
>>>>>>table.
>> <snip>
>>
>> It cannot be! Comparisons on each case must be made, there is no single
>> leaf.
>
>It's rather simple, something like:
>
>switch (x) {
> case 1:
> f1();
> break;
> case 2:
> f2();
> break;
>.
>.
>.
> case <n>:
> f<n>;
> break;
>}
>
>might be implemented (in pseudo assembler)
>
>.data
>label branchtable
>Lcont
>L1
>L2
>.
>.
>.
>L<n>
>
>.code
>
>; value is in accumulator X
>
>CMP X,<n>
>JGT Lcont
>JMP branchtable[x]
>L1:
>call f1
>JMP Lcont
>L2:
>call f2
>JMP Lcont
>.
>.
>.
>L<n>:
>CALL f<n>
>Lcont:
>
>Again, this is pretty basic stuff, consult a good book on compilers.
>
>M4
Looks pretty basic. A single comparison of a value in a range (seemingly continuous)
that is the offset into a table (data) that hold the absolute jump addresses.
Its the going from here:
CMP X,<n>
to here:
JMP branchtable[x]
thats got me. I haven't done assembly in a long time, if I were paid to do it I would.
I do remember doing thousands and thousands of hand written machine code lines before assemblers.
Mostly 8-bit. Then some stuff with Masm 5.1 and eproms for a while. Mostly frogotten.
Thats why I look at your pseudo assembler and wonder if there is a hidden meaning in CMP X,<n>
the '<n>' especially. It might be benificial to view dissasembly (preferably after c2 pass)
to see if they actually invented some new 'op' code or something that would be a miracle and
shorten your assembly down to what appears to be really only a very few machine cycles.
So that this:
if (x == 1)
f1();
else
CMP X,1
JRNE 16
call f1
JMP Lcont
if (x == 2)
f2();
else
CMP X,2
JRNE 16
call f2
JMP Lcont
...
Lcont:
will forever be looked on as bad code as will this:
switch (x) {
case 1:
f1();
case 2:
case 109827:
fall();
break;
}
-sln
------------------------------
Date: Sat, 11 Jul 2009 00:03:12 -0400
From: Ralph Malph <ralph.malph@altavista.com>
Subject: Re: Calling 'C' routines from perl.
Message-Id: <h392uc$c9j$1@aioe.org>
Prathap wrote:
> Hi All:
>
>
> Can someone let me know how to invoke a 'C' routine from perl. I
> have to develop an application
> that requires Perl and C interactions. I need to know this in
> detail. Please provide me with exmples or referances where I can learn
> this.
>
> Thanks for the help in advance.
>
> Regards,
> Prathap
Sorry shitskin...no aid to the enemy.
------------------------------
Date: Fri, 10 Jul 2009 22:33:35 -0500
From: brian d foy <brian.d.foy@gmail.com>
Subject: Re: FAQ 4.28 How do I change the Nth occurrence of something?
Message-Id: <100720092233356302%brian.d.foy@gmail.com>
In article
<937440cb-1d0a-4d4d-9496-f99769d2b3ed@x5g2000prf.googlegroups.com>,
C.DeRykus <derykus@gmail.com> wrote:
> On Jul 9, 10:48 am, anno4...@radom.zrz.tu-berlin.de wrote:
> Or, use /gc and stop one short of the match count:
>
> my $n = 5;
> my $re = qr/(whom?)ever/;
>
> $str =~ /$re/gc} for 1 .. $n-1; # position at match-1
> $str =~ s/\G(.*?)$re/$1${2}soever/ # replace next if any
ah, very tricky. After the for(), the pos ends up either after any
possible matches in the failure case, or right before the next possible
one.
------------------------------
Date: Fri, 10 Jul 2009 22:18:20 -0700
From: "Reid Tardis" <reid@tardis-db.co.uk>
Subject: ImageShack Hacked - Popular Image Hosting Website Vandalized
Message-Id: <zgV5m.423$dW5.324@newsfe04.iad>
Hacked
http://www.kevinkatovic.com/2009/07/imageshack-hacked-popular-image-hosting.html -
ImageShack.us Hacked check out what it looked like!
------------------------------
Date: Fri, 10 Jul 2009 22:34:13 +0200
From: Martijn Lievaart <m@rtij.nl.invlalid>
Subject: Re: Perl Fails To List All The Multiple Matches In The Same Line?
Message-Id: <57lki6-9mn.ln1@news.rtij.nl>
On Thu, 09 Jul 2009 14:09:13 -0700, sln wrote:
> Why can't windows do unix?
In this case, it can. Install cygwin.
HTH,
M4
------------------------------
Date: Fri, 10 Jul 2009 14:34:52 -0700
From: Jürgen Exner <jurgenex@hotmail.com>
Subject: Re: Perl Fails To List All The Multiple Matches In The Same Line?
Message-Id: <2qcf55dgibgfr5ha060n7f8egsffg2nd22@4ax.com>
Martijn Lievaart <m@rtij.nl.invlalid> wrote:
>On Thu, 09 Jul 2009 14:09:13 -0700, sln wrote:
>
>> Why can't windows do unix?
"Why can't a Ford do a Chevy?"
>In this case, it can. Install cygwin.
That doesn't "do Unix" (whatever that is supposed to mean).
It merely provides the typical Unix utilities in the Windows
environment.
jue
------------------------------
Date: Sat, 11 Jul 2009 14:18:10 -0700
From: sln@netherlands.com
Subject: Re: To extract file name only from a file
Message-Id: <povh55h6v44hdd0ij8nlhtrcua610bjbvb@4ax.com>
On Thu, 9 Jul 2009 08:00:03 -0700 (PDT), Rider <clearguy02@yahoo.com> wrote:
>
>Hi experts,
>
>I have this file, inut.txt (listed below). each line in the file has
>more than 10 fields, but I am just listing a sample format here.
>
>I need to print out only the filenames that are ending with .txt in
>the output..
>
>The output should be:
>===============
>unixFile1.txt
>unixFile2.txt
>unixFile3.txt
>...
>..
>===============
>
>I am looking out for a shorter form of a reg exp to extract only the
>file names in to the output here. I do the basic perl coding on an
>occasional basis, but don't know the right reg exp to do it.
>
>Thanks in advance,
>J
>
>
>Here is the input file.
>===================
>1, bob, usr/tst/unixFile1.txt, boston, text1, text2, text3
>2, bob, usr/tst/unixFile2.txt, boston, text1, text2, text3
>3, bob, usr/tst/unixFile3.txt, boston, text1, text2, text3
>.....
>....
>===================
This might help. Its a construct your own recipe. How you use it
is up to you. Certainly not a 1-liner (or short) but neither is real
file name parsing. There might be a module you could invoke.
Or you could use something like:
/(?:(\/\s*[.-]+.*?)|([a-z0-9_][a-z0-9_ .-]*\.txt))[\s,]+/i and defined $2
-sln
----------------------------
## parse_fname_unix.pl
## (some rudimentary regex construction)
##
use strict;
use warnings;
use constant debug => 1;
my $start_char = "a-z0-9_";
my $body_chars = "$start_char .-";
my $field_seps = "\\s,";
my $fname = "[$start_char][$body_chars]*";
my $ext = "txt";
my $bad_fname = "\/\\s*[.-]+.*?";
my $qualified_name = qr/(?:($bad_fname)|($fname\.$ext))[$field_seps]+/i;
print "\n$qualified_name\n";
while (<DATA>)
{
next if (/^\s*$/);
if (debug) {
print "\n$_";
while (/$qualified_name/g)
{
print "\tBAD: $1\n" if defined $1;
print "\tOK: $2\n" if defined $2;
}
} else {
while (/$qualified_name/g and defined $2) {
print "$2\n";
}
}
}
__DATA__
-4, bob, unix/ .txt/File_-4.txt, boston, text1, unix/tst.txt/File_-4a.txt
-3, bob, unix .txt/File_-3.txt, boston, text1, text2, text3
-2, bob, unix .txt/.-File_-2.txt, boston, text1, text2, text3
-1, bob, unix .txt.-File_-1.txt, boston, text1, text2, text3
0, bob, unixFile0.txt, boston, text1, text2, text3
1, bob, usr/tst/unixFile1.txt, boston, text1, text2, text3
2, bob, usr/tst/unixFile2.txt, boston, text1, text2, text3
3, bob, usr/tst/unix.some.txt.File3.txt, boston, text1, text2, text3
4, bob, usr/tst.txt/unixFile4.Txt, boston, text1, text2, text3
--------------------
output:
(?i-xsm:(?:(/\s*[.-]+.*?)|([a-z0-9_][a-z0-9_ .-]*\.txt))[\s,]+)
-4, bob, unix/ .txt/File_-4.txt, boston, text1, unix/tst.txt/File_-4a.txt
BAD: / .txt/File_-4.txt
OK: File_-4a.txt
-3, bob, unix .txt/File_-3.txt, boston, text1, text2, text3
OK: File_-3.txt
-2, bob, unix .txt/.-File_-2.txt, boston, text1, text2, text3
BAD: /.-File_-2.txt
-1, bob, unix .txt.-File_-1.txt, boston, text1, text2, text3
OK: unix .txt.-File_-1.txt
0, bob, unixFile0.txt, boston, text1, text2, text3
OK: unixFile0.txt
1, bob, usr/tst/unixFile1.txt, boston, text1, text2, text3
OK: unixFile1.txt
2, bob, usr/tst/unixFile2.txt, boston, text1, text2, text3
OK: unixFile2.txt
3, bob, usr/tst/unix.some.txt.File3.txt, boston, text1, text2, text3
OK: unix.some.txt.File3.txt
4, bob, usr/tst.txt/unixFile4.Txt, boston, text1, text2, text3
OK: unixFile4.Txt
------------------------------
Date: 6 Apr 2001 21:33:47 GMT (Last modified)
From: Perl-Users-Request@ruby.oce.orst.edu (Perl-Users-Digest Admin)
Subject: Digest Administrivia (Last modified: 6 Apr 01)
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------------------------------
End of Perl-Users Digest V11 Issue 2515
***************************************
