If
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you need a Perl solution to an actual real-life problem, or
you're unsure why something you've tried just isn't working...
then this section is the place to ask. Post a new question!
However, you might consider asking in the chatterbox first (if you're a
registered user). The response time tends to be quicker, and if it turns
out that the problem/solutions are too much for the cb to handle, the
kind monks will be sure to direct you here.
In the following piece of markdown text, I want to replace the spaces with a hyphen and also make the link absolute with a slash in front. So I want to go from:
I'm drawing a blank on how I might loop through all matches to links and modify those matches. Or maybe there is an entirely better way of pulling this off. Thanks!
UPDATE:
OK, I noodled around with this some more. On a lark, I tried a "global" match (which I didn't know existed outside substitution), and came up with this:
my $text = "blah blah [click me](click me) more stuff\nblah [link here
+](link here) blah blah";
$text =~ s/(\[[^]]+]\()/$1\//g; # make links absolute
my @matches = $text =~ /(\[[^]]+]\(\/)([^\)]+)/g;
while (@matches) {
my $part1 = shift @matches;
my $part2 = shift @matches;
my $orig_part2 = $part2;
$part2 =~ s/ /-/g;
$text =~ s/\Q$part1$orig_part2\E/$part1$part2/g;
}
I noticed that B::Xref had problems listing a subroutine so I took a look into the optree only to see that the name isn't properly displayed there.
file 1 and 2 are only different in the order of sub definition and call. as you can see at the line marked as ### the name fooxx is missing in version 2.
What's the problem?
I actually also did a Xref,-r which was buggy too, (the definition of &fooxx was located in in the B.pm file) but the output is just too verbose, to be shown here.
D:\exp>perl -MO=Xref,-d t_XREF_bug1.pl
File t_XREF_bug1.pl
Subroutine (main)
Package main
&fooxx &1 ###
t_XREF_bug1.pl syntax OK
D:\exp>perl -MO=Xref,-d t_XREF_bug2.pl
File t_XREF_bug2.pl
Subroutine (main)
Package (lexical)
&? &4 ###
t_XREF_bug2.pl syntax OK
D:\exp>
D:\exp>type t_XREF_bug1.pl
fooxx();
sub fooxx {
print @_;
}
D:\exp>perl -MO=Concise,-stash="main",-main,-src t_XREF_bug1.pl
FUNC: *main::fooxx ###
6 <1> leavesub[1 ref] K/REFC,1 ->(end)
- <@> lineseq KP ->6
# 3: print @_;
1 <;> nextstate(main 2 t_XREF_bug1.pl:3) v ->2
5 <@> print sK ->6
2 <0> pushmark s ->3
4 <1> rv2av[t2] lK/1 ->5
3 <#> gv[*_] s ->4
main program:
c <@> leave[1 ref] vKP/REFC ->(end)
7 <0> enter ->8
# 1: fooxx();
8 <;> nextstate(main 1 t_XREF_bug1.pl:1) v:{ ->9
b <1> entersub[t2] vKS/TARG ->c
- <1> ex-list K ->b
9 <0> pushmark s ->a
- <1> ex-rv2cv sK/1 ->-
a <#> gv[*fooxx] s/EARLYCV ->b ###
# 6:
- <;> ex-nextstate(main 3 t_XREF_bug1.pl:6) v:{ ->c
t_XREF_bug1.pl syntax OK
D:\exp>type t_XREF_bug2.pl
sub fooxx {
print @_;
}
fooxx();
D:\exp>perl -MO=Concise,-stash="main",-main,-src t_XREF_bug2.pl
FUNC: *main::constant:: ###
6 <1> leavesub[1 ref] K/REFC,1 ->(end)
- <@> lineseq KP ->6
# 2: print @_;
1 <;> nextstate(main 2 t_XREF_bug2.pl:2) v ->2
5 <@> print sK ->6
2 <0> pushmark s ->3
4 <1> rv2av[t2] lK/1 ->5
3 <#> gv[*_] s ->4
main program:
c <@> leave[1 ref] vKP/REFC ->(end)
7 <0> enter ->8
# 4: fooxx();
8 <;> nextstate(main 3 t_XREF_bug2.pl:4) v:{ ->9
b <1> entersub vKS ->c
- <1> ex-list K ->b
9 <0> pushmark s ->a
- <1> ex-rv2cv sK/1 ->-
a <#> gv[IV \] s ->b ###
t_XREF_bug2.pl syntax OK
D:\exp>
I am working through a book where it uses perl to learn network programming. With a client written in a similar manner as to this server, the udp datagram is a little bit of text. When I run the program and send the packet it just sits in the receiv queue. I see this using netstat on all listening ports does anyone know how to not have it hold them in there and just process them?
#! /usr/bin/perl -w
use strict;
use Socket;
use constant SIMPLE_UDP_PORT => 4001;
use constant MAX_RECV_LEN => 1500;
use constant LOCAL_INETNAME => 'localhost';
my $trans_serv = getprotobyname('udp');
my $local_host = pack "C4", split('\.', "127.0.0.1");
my $local_port = shift || SIMPLE_UDP_PORT;
my $local_addr = sockaddr_in($local_port, INADDR_ANY);
socket(UDP_SOCK, PF_INET, SOCK_DGRAM, $trans_serv);
bind(UDP_SOCK, $local_addr);
my $data;
while(1)
{
my $from_who = recv(UDP_SOCK, $data, MAX_RECV_LEN, 0);
if ($from_who)
{
my($the_port, $the_ip) = sockaddr_in($from_who);
warn 'Received from ', inet_ntoa($the_ip), ": $data\n";
}
else
{
warn "Problem with recv: $!\n";
}
}
But in this case it has unexpected results. This is the 1st part where a hash is constructed based on whether a key in another hash exists:
use strict;
use warnings;
use Data::Dumper;
my %tests = (
'a' => 10,
'b' => 20,
);
my $m;
# this seems to assign $m once and never bother to check again
my %hash = (
'b' => exists($tests{'b'}) && defined($m=$tests{'b'}) ? $m : 0,
'a' => exists($tests{'b'}) && defined($m=$tests{'a'}) ? $m : 0,
);
print Dumper(\%hash);
# this works as expected
$m = 10;
my %hash2 = (
'1' => $m++,
'2' => $m++,
'3' => $m++
);
print Dumper(\%hash2);
Hello all. I have been playing around with Per::Critic on the command line and found to my dismay that some of my modules do not pass gentle. I realize that I can ignore the recommendations of Perl critic, but I would love for my modules to pass "gentle" before I begin ignoring things.
The most common issue is that I modify $_ in list functions. The following is a convenient and short one liner to put the lines of files into a list. I thought doing it this way was nice and slim.
my @list = map { chomp($_); $_ } <$fh>;
my @uc_list = map { chomp $_; [uc $_] } <$lc_fh>; # used only onc
+e
my @split_list = map { chomp $_; [ split(/\|/, $_) ] } <$piped_fh>;
+# used only once
If this is something ignored usually, I will ignore it, but I would like to know how to make it better. Should I just assign $_ to a variable and then use the variable?
Another thing that I am confused by is why the expression form of eval is discouraged?
The rest of the gentle issues are me being lazy with conditionals. While writing I was thinking my $var = "foo" if 'some condition', but Perl critic does not like it, but it is fixed easily.
NOTE: Please see my update. Most are fixed, but the eval problem remains.
My OS is Debian 10 (Buster); my perl versions are 5.28.1 local and 5.8.8 on web host.
No matter how hysterical I get, my problems are not time sensitive. So, relax, have a cookie, and a very nice day!
I'm still processing what I experienced at TPC. I've had time to catch up on some of the youtube videos from the ones I missed. Sometime in all the zooming, I thought I heard one of the presenters say
that's why we eval version
I thought it was Sawyer X, who says a lot of things parenthetically, but I went over his talk for a third time and didn't hear it again. I didn't understand what he meant, so I could well have misheard it or just dreamed up the recollection wholesale.
A couple days later, I'm going through the guts of a test script for local::lib and I see this, beginning line 16 of xt/bootstrap.t
sub check_version {
my ($perl, $module) = @_;
my @inc = `$perl -le "print for \@INC"`;
chomp @inc;
(my $file = "$module.pm") =~ s{::}{/}g;
($file) = grep -e, map { "$_/$file" } @inc;
return undef
unless $file;
my $version = MM->parse_version($file);
eval $version;
}
Got at specific problem, that I need some hints on. :-)
I got a bunch of fixed size .png images with logos. Those logos are centered on the images, and empty space on the left/right of the logo, is transparent background. I need to crop those images on the fly, so that empty space on the left/right of the logo is removed.
