Planet Perl

wxPerl Revival

dev.to #perl

Published by Johan Vromans on Saturday 12 October 2024 19:09

For several years now, development and support of wxPerl, the interface library between Perl and wxWidgets, has stalled. The latest release was based on Perl 5.16 and wxWidgets 2.9.

Meanwhile some active users have made attempts to port wxPerl to newer versions of Perl and wxWidgets, with varying results. Microsoft Windows and Apple macOS provide additional challenges.

I believe in user-friendly desktop based GUI applications written in Perl and wxPerl is an excellent tool to develop these applications that are deployable across different desktop platforms. I hate to see wxPerl rusting away in the archives.

If you are using wxPerl and want to keep using it with recent
versions of Perl and wxWidgets, please join the mailing list.

As a start, I've set up a new, independent repo for wxPerl on GitHub.

It currently has two branches: wx30 and master.

Branch wx30 contains an updated version of the last 'official' release 0.9932, fixed for modern Perl and wxWidgets 3.0. I have released it on GitHub as Wx-0.9933.

The master branch has been updated with all necessary changes for wxWidgets 3.2. Also some constants and methods have been added to deploy some 3.2 functionality. I have released it on GitHub as Wx-3.001. More will be added in the future but will require help from Perl/XS experts.

I found the easiest way to install gcc on Windows — Just install Straberry Perl

Perl on Medium

Published by Aishik Nath on Saturday 12 October 2024 05:35

Yes, you read that right. Just install Straberry Perl and gcc will be properly installed in your Windows machine.

Continue reading on Medium »

Double Luhn

dev.to #perl

Published by Simon Green on Saturday 12 October 2024 03:11

Weekly Challenge 290

Each week Mohammad S. Anwar sends out The Weekly Challenge, a chance for all of us to come up with solutions to two weekly tasks. My solutions are written in Python first, and then converted to Perl. It's a great way for us all to practice some coding.

Challenge, My solutions

Task 1: Double Exist

Tasks

You are given an array of integers, @ints.

Write a script to find if there exist two indices $i and $j such that:

$i != $j
0 <= ($i, $j) < scalar @ints
$ints[$i] == 2 * $ints[$j]

My solution

This seems relatively straight forward, but there is a massive gotcha that hopefully other Team PWC members also noticed. For this task, I loop through the list and see if a value that is twice its value exist.

However, if the value is '0' (and thus 0 × 2 = 0), I need to check that there were at least two zeros in the list.

def double_exists(ints: list) -> bool:

    for i in ints:
        if i * 2 in ints:
            if i != 0 or ints.count(0) > 1:
                return True

    return False

Examples

$ ./ch-1.py 6 2 3 3
true

$ ./ch-1.py 3 1 4 13
false

$ ./ch-1.py 2 1 4 2
true

$ ./ch-1.py 1 3 0
false

$ ./ch-1.py 1 0 3 0
true

Task 2: Luhn’s Algorithm

Task

You are given a string $str containing digits (and possibly other characters which can be ignored). The last digit is the payload; consider it separately. Counting from the right, double the value of the first, third, etc. of the remaining digits.

For each value now greater than 9, sum its digits.

The correct check digit is that which, added to the sum of all values, would bring the total mod 10 to zero.

Return true if and only if the payload is equal to the correct check digit.

My solution

I start this task by removing non-digit characters from the string, and turn the reversed string into a list of integers.

I then use the supplied formula, alternating between adding the value to count or multiplying it by two and removing 9. If the resulting count is divisible by 10, I return True, otherwise I return False.

def luhn_algorithm(s: str) -> bool:
    s = re.sub('[^0-9]', '', s)
    ints = [int(n) for n in s[::-1]]

    count = 0
    for pos, i in enumerate(ints):
        if pos % 2 == 1:
            i *= 2
            if i > 9:
                i -= 9
        count += i
    return count % 10 == 0

Examples

$ ./ch-2.py  17893729974
true

$ ./ch-2.py  "4137 8947 1175 5904"
true

$ ./ch-2.py "4137 8974 1175 5904"
false

Finding Double Existence and Applying Luhn's Algorithm

dev.to #perl

Published by André Plöger on Friday 11 October 2024 19:50

In this article, we will address two engaging tasks from the Perl Weekly Challenge #290: checking for double existence in an array and implementing Luhn's Algorithm for validation. We'll implement solutions in both Perl and Go.

Double Existence

The first task involves finding if there exist two indices $i and $j such that:

1. $i != $j
2. 0 <= ($i, $j) < scalar @ints
3. $ints[i] = 2 * $ints[j]

Task Description

Input: An array of integers, @ints.

Output: true if the condition is met; otherwise, false.

Examples:

Input: @ints = (6, 2, 3, 3)
Output: true

For $i = 0, $j = 2
$ints[$i] = 6 => 2 * 3 =>  2 * $ints[$j]

Input: @ints = (3, 1, 4, 13)
Output: false

Input: @ints = (2, 1, 4, 2)
Output: true

For $i = 2, $j = 3
$ints[$i] = 4 => 2 * 2 =>  2 * $ints[$j]

Solution

Perl Implementation
In the Perl implementation, we use a hash to track seen integers and check if either half or double of the current number exists in the hash.

sub double_exist {
    my %seen;

    foreach my $num (@_) {
        return 1 if exists $seen{$num / 2} || exists $seen{$num * 2};
        $seen{$num} = 1;
    }

    return 0;
}

Go Implementation
The Go implementation follows a similar logic, using a map to keep track of unique integers.

func doubleExist(ints []int) bool {
    seen := make(map[int]bool)

    for _, num := range ints {
        if (num%2 == 0 && seen[num/2]) || seen[num*2] {
            return true
        }
        seen[num] = true
    }

    return false
}

Luhn's Algorithm

The second task involves implementing Luhn's Algorithm to validate a string of digits, ignoring non-digit characters. The last digit is considered separately as the payload.

Task Description

You are given a string str containing digits (and possibly other characters which can be ignored). The last digit is considered as the payload and handled separately.

Counting from the right, double the value of the first, third, etc., of the remaining digits.
For each value now greater than 9, sum its digits.
The correct check digit is the one that, when added to the sum of all values, brings the total modulo 10 to zero.

Return true if the payload equals the correct check digit; otherwise, return false.

Examples:

Input: "17893729974"
Output: true

Payload is 4.

Digits from the right:

7 * 2 = 14, sum = 5
9 = 9
9 * 2 = 18, sum = 9
2 = 2
7 * 2 = 14, sum = 5
3 = 3
9 * 2 = 18, sum = 9
8 = 8
7 * 2 = 14, sum = 5
1 = 1

Sum of all values = 56, so 4 must be added to bring the total mod 10 to zero. The payload is indeed 4.

Input: "4137 8947 1175 5904"
Output: true

Input: "4137 8974 1175 5904"
Output: false

Solution

Perl Implementation
The Perl implementation processes the input string to ignore non-digit characters, then applies Luhn's algorithm to validate the number.

sub luhn_check {
    my ($str) = @_;
    $str =~ s/[^0-9]//g;

    my $payload = substr($str, -1);
    my $sum = 0;
    my $length = length($str);

    for (my $i = 0; $i < $length - 1; $i++) {
        my $digit = substr($str, $length - 2 - $i, 1);
        if ($i % 2 == 0) {
            $digit *= 2;
            $digit -= 9 if $digit > 9;
        }
        $sum += $digit;
    }

    my $check_digit = (10 - ($sum % 10)) % 10;

    return $payload == $check_digit ? 1 : 0;
}

Go Implementation
The Go version implements the same logic, utilizing the unicode package to filter out non-digit characters.

func luhnCheck(str string) bool {
    sum := 0
    payload := 0
    digits := []int{}

    for _, char := range str {
        if unicode.IsDigit(char) {
            digit := int(char - '0')
            digits = append(digits, digit)
        }
    }

    if len(digits) == 0 {
        return false
    }

    payload = digits[len(digits)-1]

    for i := 0; i < len(digits)-1; i++ {
        digit := digits[i]
        if (len(digits)-2-i)%2 == 0 {
            digit *= 2
            if digit > 9 {
                digit -= 9
            }
        }
        sum += digit
    }

    checkDigit := (10 - (sum % 10)) % 10

    return payload == checkDigit
}

Conclusion

In this article, we explored two interesting programming challenges: finding double existence in an array and implementing Luhn's Algorithm for validation. These tasks highlight how different programming languages can tackle similar problems with their own unique approaches. I hope these examples inspire you to delve deeper into both Perl and Go!

You can find the complete code, including tests, on GitHub.

perlfunc - update each documentation with foreach examples

Perl commits on GitHub

Published by Grinnz on Friday 11 October 2024 15:42

perlfunc - update each documentation with foreach examples

Also mention multiple-value foreach as a new alternative, and fix a hash dereference in a previous example.

Silence clang compilation warning

Perl commits on GitHub

Published by khwilliamson on Friday 11 October 2024 15:41

Silence clang compilation warning

Commit 9acaa9844a1adc113059335846a097b435800a22 introduced a compilation
warning that I only have seen with clang.  Casting appropriately gets
rid of it.

London Perl & Raku Workshop 2024 Silver Sponsors

blogs.perl.org

Published by London Perl Workshop on Friday 11 October 2024 14:30

This year's London Perl and Raku Workshop will take place on 26th Oct 2024. Without our sponsors this event would not happen and we would like to thank them.

Perl developers are hard to get. As the leading language of the dotcom boom, Perl is one of the best-paid languages worldwide, yet Perl training seldom features on university curricula. But that doesn't have to cause a headache for employers trying to expand their Perl team.

Geekuni can give software developers with no previous Perl experience the training they need, as they need it. So, whether you’re looking to provide new recruits with online Perl training from day one of the onboarding process or upskill existing talent, Geekuni has the training package to empower your staff with Perl.

To find out more, go here: https://geekuni.com/corporate-perl-training or email andrew@geekuni.com

Geizhals Preisvergleich is one of the largest product and price comparison platforms in the German-speaking area.

For now over 20 years, our company has proven itself in a highly competitive, dynamic industry.

We attribute our success to an uncompromising implementation of our company philosophy: transparency, objective and user-oriented information, and the quality of our content.

The Geizhals Preisvergleich teach team has been a proud user and supporter of the Perl programming language since the founding of the company. In the last months this includes directly supporting development for the "Corinna in Core" project.

Datensegler e.U. is a small team of Perl enthusiasts specialized in agile software development and PostgreSQL consulting from Vienna, Austria and are happy to sponsor the LPW2024.

We use Perl in the majority of our projects both for web applications (shout-out to the formidable Mojolicious framework) and backend tasks from ETL to web scraping since, well basically forever.

We also offer PostgreSQL consulting, including developer support, optimization and operating. If you want to migrate from Oracle or MySQL to PostgreSQL we can lend a helping hand too.

Founded in 2004 and based in Manchester, SpareRoom is the largest flatmate finding service in the UK and globally. Sharing isn’t just at the heart of our business - it IS our business. We are dedicated to helping people find more than just a room; we help them find the right people to live with and turn their flatshare into their home.

A Perl company from the start, we continue to enhance our services using modern Perl, thanks to our small but talented team of seasoned Perl developers and our commitment to training junior developers as they embark on their Perl journey. We are usually on the lookout for Perl talent, so feel free to contact us through our jobs page.

Our commitment to Perl and open-source software is strong. You can often find our team members either attending or speaking at Perl events, or contributing to CPAN and other open-source projects. Thus, we are proud to sponsor the London Perl Workshop as it makes its return, an event we have eagerly awaited and supported.

This week in PSC (163) | 2024-10-10

blogs.perl.org

Published by Perl Steering Council on Friday 11 October 2024 04:21

We had a guest this week: Olaf Alders.

We exchanged Perl (re)branding ideas with Olaf. We will be keeping in touch on that front.
We discussed the feedback on feature-guarding and unbundling apostrophe. We came up with a strategy to propose that we think should work, which will be posted on the relevant thread.
We discussed the fact that keeping the current smartmatch operator (as a feature) means we can’t have a meaningful air gap to prevent subtle bugs when moving to a future “good” smartmatch. This probably implies that we would be giving up on any future smart match operator, but there are usually better replacements.

[P5P posting of this summary]

Perl Weekly Challenge 290: Double Exist

blogs.perl.org

Published by laurent_r on Friday 11 October 2024 03:20

These are some answers to the Week 290, Task 1, of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a few days from now (on October 13, 2024, at 23:59). This blog post provides some solutions to this challenge. Please don’t read on if you intend to complete the challenge on your own.

Task 1: Double Exist

You are given an array of integers, @ints.

Write a script to find if there exist two indices $i and $j such that:

1) $i != $j
2) 0 <= ($i, $j) < scalar @ints
3) $ints[$i] == 2 * $ints[$j]

Example 1

Input: @ints = (6, 2, 3, 3)
Output: true

For $i = 0, $j = 2
$ints[$i] = 6 => 2 * 3 =>  2 * $ints[$j]

Example 2

Input: @ints = (3, 1, 4, 13)
Output: false

Example 3

Input: @ints = (2, 1, 4, 2)
Output: true

For $i = 2, $j = 3
$ints[$i] = 4 => 2 * 2 =>  2 * $ints[$j]

I initially didn't understand condition (2). This ($i, $j) expression didn't make sense to me, until I understood that it meant that both $i and $j have to be greater than or equal to zero, and smaller than the number of items in the array.

Note that the first condition, $i != $j, is unnecessary since, if $i == $j, then we cannot meet condition (3), $ints[$i] == 2 * $ints[$j]. Well, that is except if the value is 0, but zeros should be avoided anyway because we could have 0 = 2 * 0, which is technically true, but that's not really the meaning of the task. I'll therefore consider that the input should be an array of non-zero integers because what we should do with the zero special case is unclear and not specified in the task. Thus, there is no need to check condition (1) in our code (this applies only to the Perl implementation, as we don't have this issue with the Raku implementation).

Double Exist in Raku

In Raku, the built-in combinations routine make it possible to generate automatically all combinations of two items of an array. Combinations are unordered. In other words, with an input such as <1 2 3>, the combinations method will generate the following combinations: (1 2) (1 3) (2 3), but not (2, 1), (3, 1), or (3, 2). Therefore, for each combination, we need to compare both ways: is the first item the double of the second, and is the second item the double of the first.

sub double-exists (@in) {
    for @in.combinations: 2 -> $comb {
        return True if $comb[0] == 2 * $comb[1] or 
            $comb[1] == 2 * $comb[0];
    }
    False;
}

my @tests = <1 2 3 4>, <6 2 3 3>, <3 1 4 13>, <2 1 4 2>;
for @tests -> @test {
    printf "%-10s => ", "@test[]";
    say double-exists @test;
}

This program displays the following output:

$ raku ./double-exists.raku
1 2 3 4    => True
6 2 3 3    => True
3 1 4 13   => False
2 1 4 2    => True

Double Exist in Perl

Perl doesn't have a built-in combinations subroutine, so we will apply the canonical method of generating them (as well as those reversing the value order) using two nested loops. Please read my comments at the beginning of this post concerning the first condition ($i != $j) and the need to avoid zero values in the input. If you disagree with my view, it is very easy to add a code list such as:

next if $i == $j;

in the inner loop of the code below.

sub double_exists {
    for my $i (0..$#_) {
        for my $j (0..$#_) {
            return "True" if $_[$i] == 2 * $_[$j];
        }
    }
    return "False";
}

my @tests = ( [1, 2, 3, 4], [6, 2, 3, 3 ], 
              [3, 1, 4, 13], [2, 1, 4, 2] );
for my $test (@tests) {
    printf "%-10s => ", "@$test";
    say double_exists @$test;
}

This program displays the following output:

$ perl ./double-exists.pl
1 2 3 4    => True
6 2 3 3    => True
3 1 4 13   => False
2 1 4 2    => True

Wrapping up

The next week Perl Weekly Challenge will start soon. If you want to participate in this challenge, please check https://perlweeklychallenge.org/ and make sure you answer the challenge before 23:59 BST (British summer time) on October 20, 2024. And, please, also spread the word about the Perl Weekly Challenge if you can.

Weather::OWM released on CPAN

blogs.perl.org

Published by Dimitrios Kechagias on Friday 11 October 2024 00:15

I am in the process of adding OpenWeatherMap support to Xasteria Weather for iOS and the proxy I built is in Perl. Since there was only an old module on CPAN which did not support the current API and was not easily updatable, I released Weather::OWM. It's a very simple module, similar to two other Weather modules I've released in the past (Weather::WeatherKit and Weather::Astro7Timer).
The OpenWeather API has a Free tier with both current weather and forecast, which makes the module useful to anyone interested in fetching weather for any location. E.g.


use Weather::OWM;
 
my $owm = Weather::OWM->new(key => 'Your API key');

# Get current weather for the Stonehenge area using lat/lon...

my %r = $owm->get_weather(lat => 51.18, lon => -1.83);

 

# ...and print temperature, humidity, wind speed

say "$r{main}->{temp}C $r{main}->{humidity}% $r{wind}->{speed}m/s"

    unless $r{error};

# Get 3h/5d forecast for London, UK...

%r = $owm->get_weather(product => 'forecast', loc => 'London,UK');

 

# ...print the temperature for every 3 hours over the next 5 days

say scalar(localtime($_->{dt}))." $_->{main}->{temp}C"

    for @{$r{list}};

Perl Weekly Challenge 290: Luhn's Algorithm

blogs.perl.org

Published by laurent_r on Thursday 10 October 2024 17:30

These are some answers to the Week 290, Task 2, of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a few days from now (on October 13, 2024, at 23:59). This blog post provides some solutions to this challenge. Please don’t read on if you intend to complete the challenge on your own.

Task 2: Luhn’s Algorithm

You are given a string $str containing digits (and possibly other characters which can be ignored). The last digit is the payload; consider it separately. Counting from the right, double the value of the first, third, etc. of the remaining digits.

For each value now greater than 9, sum its digits.

The correct check digit is that which, added to the sum of all values, would bring the total mod 10 to zero.

Return true if and only if the payload is equal to the correct check digit.

It was originally posted on reddit.

Example 1

Input: "17893729974"
Output: true

Payload is 4.

Digits from the right:

7 * 2 = 14, sum = 5
9 = 9
9 * 2 = 18, sum = 9
2 = 2
7 * 2 = 14, sum = 5
3 = 3
9 * 2 = 18, sum = 9
8 = 8
7 * 2 = 14, sum = 5
1 = 1

Sum of all values = 56, so 4 must be added to bring the total mod 10 to zero. The payload is indeed 4.

Example 2

Input: "4137 8947 1175 5904"
Output: true

Example 3

Input: "4137 8974 1175 5904"
Output: false

The Luhn algorithm is a simple check digit formula (or checksum) used to validate a variety of identification numbers.

The algorithm was invented in 1960 and is in wide use today. It is aimed at protecting against accidental typing errors. Most credit cards and many government identification numbers use the algorithm as a simple method of distinguishing valid numbers from mistyped or otherwise incorrect numbers.

This task has real life applications. In my professional career as a contractor for a tier-one cell phone operator for 26 years, I implemented the Luhn algorithm at least three times (in three different programming languages, including Perl, but I no longer have the code developed then, so I had to re-implement it from scratch for this task). In the mobile phone industry, the Luhn formula is used for validating at least two identification numbers: the International Mobile Equipment Identity (IMEI), an identifier for the phone itself, and the Integrated Circuit Card Identifier (ICCID) for the SIM card (or eSIM profile).

The algorithm described above can be simplified. Rather than performing the calculations on the identification number without the trailing check digit, we can do it directly on the whole number (with the check digit). This modified algorithm goes as follows:

Reverse the order of the digits in the number.
Take the second, fourth ... and every other even digit in the reversed digits, multiply them by two and sum the digits if the answer is greater than nine.
Add all the digits; if the sum is a multiple of 10 (ends in zero), then the original number is a valid identification number.

Luhn’s Algorithm in Raku

This program implements the modified algorithm described just above. First, the program uses a regex to remove characters that are not digits from the input string. Then it reverses the resulting string, using the flip method, and splitted into an array of individual characters (@digits), using the comb method. Then, it multiplies by 2 the values of @digits with and even index, and sums the digits of the resulting number (using a comb and sum combination. Finally, the original number is validl if the sum of all digits can be evenly divided by 10.

sub luhn ($in is copy) {
    $in ~~ s:g/\D+//;  # remove non-digits
    my @digits = $in.flip.comb;  # reverse and split
    for 0..@digits.end -> $i {
        # values for even indices don't change
        @digits[$i] = (2 * @digits[$i]).comb.sum unless $i %% 2;
    }
    return @digits.sum %% 10; # valid if sum end with a 0
}

for "17893729974", "178az93r729974", "178 9372 9 9  74",
    "4137 8947 1175 5904", "4137 8974 1175 5904" -> $test {
    printf "%-25s => ", $test;
    say luhn $test;
}

This program displays the following output:

$ raku ./luhn.raku
17893729974               => True
178az93r729974            => True
178 9372 9 9  74          => True
4137 8947 1175 5904       => True
4137 8974 1175 5904       => False

Luhn’s Algorithm in Perl

This is a port to Perl of the above Raku program. Please refer to the previous sections if you need explanations. The comb built-in is replaced by split and we implemented our own sum and sum_digits auxiliary subroutines.

use strict;
use warnings;
use feature 'say';

sub sum {
    my $sum = 0;
    for my $n (@_) {
        $sum += $n;
    }
    return $sum;
}
sub sum_digits {
    return sum split //, shift;
}

sub luhn {
    my $in = shift;
    $in =~ s/\D+//g;             # remove non-digits
    my @digits = reverse split //, $in; # reverse and split
    for my $i (0..$#digits) {
        next unless $i % 2;   #skip even indices
        my $val = 2 * $digits[$i];
        $digits[$i] = sum_digits $val;
    }
    # valid luhn if sum ends with a 0 (multiple of 10)
    return (sum @digits) % 10 == 0 ? "True" : "False"; 
}

for my $test ("17893729974", "178a93r729974", "178 9372 9 9 74",
    "4137 8947 1175 5904", "4137 8974 1175 5904") {
    printf "%-25s => ", $test;
    say luhn $test;
}

This program displays the following output:

$ perl  ./luhn.pl
17893729974               => True
178a93r729974             => True
178 9372 9 9 74           => True
4137 8947 1175 5904       => True
4137 8974 1175 5904       => False

Wrapping up

The next week Perl Weekly Challenge will start soon. If you want to participate in this challenge, please check https://perlweeklychallenge.org/ and make sure you answer the challenge before 23:59 BST (British summer time) on October 20, 2024. And, please, also spread the word about the Perl Weekly Challenge if you can.

IPC::Run and Applescript

Perl questions on StackOverflow

Published by simone on Thursday 10 October 2024 15:52

My end-goal is to:

get PNG data from the clipboard on MacOS
do stuff with it (typically with ImageMagick)
put it back onto the clipboard

and I'm trying to do that with IPC::Run in perl

It looks like the minimal example in AppleScript works:

set in_clip to get the clipboard as «class PNGf»
set the clipboard to in_clip as «class PNGf»

generates no error, and leaves the clipboard alone.

When I try to do what I think is the same in perl:

use IPC::Run qw/run/;
use utf8;

$\ = "\n"; $, = "\t";

my ($stdin, $stdout, $stderr);

run ["osascript", "-e", "get the clipboard as «class PNGf»"], \$stdin, \$stdout, \$stderr;
print ("original data:", (substr $stdout, 0, 100) . "..." . (substr $stdout, -200)) ;

run ["osascript", "-e", (sprintf qq(set the clipboard to "%s" as «class PNGf»), ($stdout =~ s/\n//gmrs))], \$stdin, \$stdout, \$stderr;

print ("convert error:", (substr $stderr, 0, 100) . (substr $stderr, -200)) ;

I get errors: the script throws:

convert 64548:64560: execution error: Can’t make "«data PNGf89504E4...26082»" into type «class PNGf»

What's going on here?

I understand this is messy and at a perilous borderline, but why?

bytes_to_utf8: Don't redo work

Perl commits on GitHub

Published by khwilliamson on Thursday 10 October 2024 14:13

bytes_to_utf8: Don't redo work

We have gone to some trouble to find the first UTF-8 variant character
in the input string.  There is no need to look again for variants in the
portion of the string that we have already determined doesn't have any
such variants.

This missing statement appears to have been an oversight.

Fix compilation warnings about UTF8_\w+_PERL_EXTENDED

Perl commits on GitHub

Published by khwilliamson on Thursday 10 October 2024 13:49

Fix compilation warnings about UTF8_\w+_PERL_EXTENDED

Commit b66abe3878e48c99de059364b052d96c7be8ee75 added these symbols to
two #defines, but neglected to remove the special casing that had been
used when it wasn't in them.

Cygwin Perl won't load DLLs anymore, perhaps due to a failure to convert cygwin paths to Windows paths

Perl questions on StackOverflow

Published by Phil Goetz on Wednesday 09 October 2024 23:10

I'm suddenly unable to run any Perl scripts under Cygwin. Every script I try to run crashes like this:

phil@TAICHI /cygdrive/h/bakE/new/virChecked
$ findFiles -s . -t /cygdrive/D/data-comp/text -u /cygdrive/E/new/virChecked/text -d -a .3
Can't load '/home/phil/perl5/lib/perl5/x86_64-cygwin-threads-multi/auto/Win32/File/File.dll' for module Win32::File: No such file or directory at /usr/lib/perl5/5.36/x86_64-cygwin-threads/DynaLoader.pm line 206.
 at /usr/local/bin/findFiles line 24.
Compilation failed in require at /usr/local/bin/findFiles line 24.
BEGIN failed--compilation aborted at /usr/local/bin/findFiles line 24.

phil@TAICHI /cygdrive/h/bakE/new/virChecked
$ pushd /home/phil/perl5/lib/perl5/x86_64-cygwin-threads-multi/auto/Win32/File/
~/perl5/lib/perl5/x86_64-cygwin-threads-multi/auto/Win32/File /cygdrive/h/bakE/new/virChecked

phil@TAICHI ~/perl5/lib/perl5/x86_64-cygwin-threads-multi/auto/Win32/File
$ ls -l File.dll
-r-xr-xr-x 1 phil None 178K Jul 14  2021 File.dll*

Sometimes perl won't open File.dll; sometimes it won't open IO.dll. In either case, the DLL is always exactly where Perl is looking for it, with world read privs; but Perl won't load it.

Line 206 of Dynaloader.pm is

my $libref = dl_load_file($file, $flags) or croak("Can't load '$file' for module $module: ".dl_error());

A comment near the start of Dynaloader says:

The load function that dl_load_file() calls may require an absolute pathname.

I can't find where dl_load_file() is defined. It isn't in Dynaloader.pm; and the only module Dynaloader includes is Config, which also doesn't have it, and includes no other files.

I suspect that some Perl module has changed, with the result that dl_load_file doesn't convert Cygwin absolute pathnames to Windows absolute pathnames. I tried reinstalling Perl 5.36.3-1, but it didn't help. I also made a new Cygwin installation and installed Perl 5.40, but it behaved the same way.

Questions:

Is anyone else currently able to use Perl in Cygwin using the lastest Cygwin packages?
Any idea what might have changed recently to make Cygwin Perl unable to use full Cygwin paths?
Where can I find a Cygwin perl distribution prior to Perl 5.32?

How to pass JSON using WWW::Mechanize in perl

Perl questions on StackOverflow

Published by Nilesh on Wednesday 09 October 2024 18:44

We are using WWW::Mechanize to send json data to our api.

My code is below.

#!/usr/local/bin/perl

use WWW::Mechanize;

sub get_csrf_token {
    my $sso = shift;
    my $referer = shift;
    my @cookie_items;
    my $rsp = $sso->get($referer);
    my $set_cookie = $rsp->header('set-cookie');
    if ($set_cookie =~ /csrftoken=(\S+);/) {
        push(@cookie_items, $1);
    }
    if ($set_cookie =~ /sessionid=(\S+);/) {
        push(@cookie_items, $1);
    }
    else {
        die 'Failed to get CSRF Token';
    }
    return @cookie_items;
}

my $sso = WWW::Mechanize->new(
        keep_alive  => 0,
        timeout     => 3000,
        stack_depth => 1,
        debug       => 1,
        verbose     => 1,
        key         => "/home/user/.athenz/key",
        cert        => "/home/user/.athenz/cert",
    );

my $referer = "https://myapi.domain.com/athenz/api/healthcheck/";
my @cookies = get_csrf_token($sso, $referer);
$sso->add_header('Referer' => $referer);
$sso->add_header('X-CSRFToken' => $cookies[0]);
$sso->add_header('Cookie' => "sessionid=$cookies[1]; csrftoken=$cookies[0]");

my %content = (
          'value' => '127.0.0.1',
          'key_name' => 'NTP_SERVERS'
);

my $response = $sso->put("https://myapi.domain.com/athenz/api/NTP_SERVERS/", \%content);

print "^^^^^^^^^^^^^^^^^^^^^^^^^\n";
print $response->code();
print "\n^^^^^^^^^^^^^^^^^^^^^^^^^\n";

its give me error Error PUTing https://myapi.domain.com/athenz/api/NTP_SERVERS/: Bad Request at /tmp/test.pm line 53

When I check server logs, its seems, the payload which I am sending, is deliver to server as HASH instead of json.

Below is apache logs.

[Mon Oct 07 18:32:27.987189 2024] [ssl:info] [pid 19745:tid 19745] [client 127.0.0.1:58372] AH01964: Connection to child 29 established (server myapi.domain.com:443)
[Mon Oct 07 18:32:27.987600 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(140): [client 127.0.0.1:58372] mod_dumpio: dumpio_in [init-blocking] 0 readbytes
[Mon Oct 07 18:32:27.987964 2024] [ssl:debug] [pid 19745:tid 19745] ssl_engine_kernel.c(2393): [client 127.0.0.1:58372] AH02043: SSL virtual host for servername myapi.domain.com found
[Mon Oct 07 18:32:27.992817 2024] [ssl:debug] [pid 19745:tid 19745] ssl_engine_kernel.c(2256): [client 127.0.0.1:58372] AH02041: Protocol: TLSv1.2, Cipher: ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)
[Mon Oct 07 18:32:27.992936 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(140): [client 127.0.0.1:58372] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:32:27.993929 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(63): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): 53 bytes
[Mon Oct 07 18:32:27.993964 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(103): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): PUT /athenz/api/NTP_SERVERS/ HTTP/1.1

[Mon Oct 07 18:32:27.994033 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(140): [client 127.0.0.1:58372] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:32:27.994047 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(63): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): 24 bytes
[Mon Oct 07 18:32:27.994056 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(103): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): TE: deflate,gzip;q=0.3

[Mon Oct 07 18:32:27.994065 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(140): [client 127.0.0.1:58372] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:32:27.994089 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(63): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): 23 bytes
[Mon Oct 07 18:32:27.994093 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(103): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): Connection: TE, close

[Mon Oct 07 18:32:27.994100 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(140): [client 127.0.0.1:58372] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:32:27.994104 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(63): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): 23 bytes
[Mon Oct 07 18:32:27.994123 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(103): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): Accept-Encoding: gzip

[Mon Oct 07 18:32:27.994127 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(140): [client 127.0.0.1:58372] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:32:27.994132 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(63): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): 45 bytes
[Mon Oct 07 18:32:27.994135 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(103): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): Host: myapi.domain.com

[Mon Oct 07 18:32:27.994139 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(140): [client 127.0.0.1:58372] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:32:27.994143 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(63): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): 84 bytes
[Mon Oct 07 18:32:27.994147 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(103): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): Referer: https://myapi.domain.com/athenz/api/healthcheck/

[Mon Oct 07 18:32:27.994151 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(140): [client 127.0.0.1:58372] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:32:27.994155 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(63): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): 32 bytes
[Mon Oct 07 18:32:27.994158 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(103): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): User-Agent: WWW-Mechanize/1.72

[Mon Oct 07 18:32:27.994185 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(140): [client 127.0.0.1:58372] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:32:27.994190 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(63): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): 128 bytes
[Mon Oct 07 18:32:27.994193 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(103): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): Cookie: sessionid=XXXXXXX; csrftoken=YYYYYYY

[Mon Oct 07 18:32:27.994198 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(140): [client 127.0.0.1:58372] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:32:27.994201 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(63): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): 19 bytes
[Mon Oct 07 18:32:27.994205 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(103): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): HASH(0x1d5b760):

[Mon Oct 07 18:32:27.994209 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(140): [client 127.0.0.1:58372] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:32:27.994213 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(63): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): 79 bytes
[Mon Oct 07 18:32:27.994217 2024] [dumpio:trace7] [pid 19745:tid 19745] mod_dumpio.c(103): [client 127.0.0.1:58372] mod_dumpio:  dumpio_in (data-TRANSIENT): X-CSRFToken: YYYYYYY

[Mon Oct 07 18:32:27.994223 2024] [core:debug] [pid 19745:tid 19745] protocol.c(1290): [client 127.0.0.1:58372 {YRA:127.0.0.1:58372, YPA:127.0.0.1:58372}] AH02426: Request header field name is malformed: HASH(0x1d5b760):, referer: https://myapi.domain.com/athenz/api/healthcheck/
[Mon Oct 07 18:32:27.994328 2024] [core:debug] [pid 19745:tid 19745] protocol.c(1482): [client 127.0.0.1:58372 {YRA:127.0.0.1:58372, YPA:127.0.0.1:58372}] AH00567: request failed: error reading the headers, referer: https://myapi.domain.com/athenz/api/healthcheck/

If I use same API with curl, it works fine and apache logs gives no error.

curl --cert ~/.athenz/cert --key ~/.athenz/key -H "Content-type: application/json" -H "X-CSRFToken: $TOKEN" --referer "https://myapi.domain.com/athenz/api/healthcheck/" --cookie "csrftoken=$TOKEN;sessionid=$SESSIONID;" "https://myapi.domain.com/athenz/api/NTP_SERVERS/" -X PUT -d '{"key_name": "NTP_SERVERS", "value": "98.139.133.27"}' -i
HTTP/1.1 200 OK
Date: Mon, 07 Oct 2024 18:26:50 GMT
P3P: policyref="https://policies.domain.com/w3c/p3p.xml", CP="CAO DSP COR CUR ADM DEV TAI PSA PSD IVAi IVDi CONi TELo OTPi OUR DELi SAMi OTRi UNRi PUBi IND PHY ONL UNI PUR FIN COM NAV INT DEM CNT STA POL HEA PRE LOC GOV"
Allow: GET, PUT, DELETE, HEAD, OPTIONS
X-Frame-Options: DENY
Vary: Cookie
Content-Length: 0
Access-Control-Allow-Methods: GET, PUT, POST, DELETE, OPTIONS
Access-Control-Allow-Credentials: true
X-Content-Type-Options: nosniff
Referrer-Policy: same-origin
Set-Cookie: csrftoken=YYYYYYYYYYY; Domain=.domain.com; expires=Mon, 06 Oct 2025 18:26:53 GMT; Max-Age=31449600; Path=/; SameSite=Lax
Set-Cookie: sessionid=XXXXXXXXXXXX; expires=Mon, 21 Oct 2024 18:26:53 GMT; HttpOnly; Max-Age=1209600; Path=/; SameSite=Lax
Cache-Control: private
Connection: close

The apache logs, which print the json I passed in the curl.

[Mon Oct 07 18:26:50.576736 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(140): [client 127.0.0.1:57073] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:26:50.935742 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(63): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): 53 bytes
[Mon Oct 07 18:26:50.935767 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(103): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): PUT /athenz/api/NTP_SERVERS/ HTTP/1.1

[Mon Oct 07 18:26:50.935821 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(140): [client 127.0.0.1:57073] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:26:50.935840 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(63): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): 31 bytes
[Mon Oct 07 18:26:50.935844 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(103): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): Host: myapi.domain.com

[Mon Oct 07 18:26:50.935848 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(140): [client 127.0.0.1:57073] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:26:50.935852 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(63): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): 24 bytes
[Mon Oct 07 18:26:50.935857 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(103): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): User-Agent: curl/8.7.1

[Mon Oct 07 18:26:50.935863 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(140): [client 127.0.0.1:57073] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:26:50.935867 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(63): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): 13 bytes
[Mon Oct 07 18:26:50.935871 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(103): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): Accept: */*

[Mon Oct 07 18:26:50.935875 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(140): [client 127.0.0.1:57073] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:26:50.935880 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(63): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): 43 bytes
[Mon Oct 07 18:26:50.935883 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(103): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): Referer: https://myapi.domain.com/api/healthcheck/

[Mon Oct 07 18:26:50.935887 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(140): [client 127.0.0.1:57073] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:26:50.935890 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(63): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): 128 bytes
[Mon Oct 07 18:26:50.935894 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(103): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): Cookie: csrftoken=YYYYYYYY;sessionid=XXXXXXX;

[Mon Oct 07 18:26:50.935908 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(140): [client 127.0.0.1:57073] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:26:50.935913 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(63): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): 32 bytes
[Mon Oct 07 18:26:50.935917 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(103): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): Content-type: application/json

[Mon Oct 07 18:26:50.935922 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(140): [client 127.0.0.1:57073] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:26:50.935926 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(63): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): 79 bytes
[Mon Oct 07 18:26:50.935930 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(103): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): X-CSRFToken: YYYYYYYYY

[Mon Oct 07 18:26:50.935934 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(140): [client 127.0.0.1:57073] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:26:50.935937 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(63): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): 20 bytes
[Mon Oct 07 18:26:50.935942 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(103): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): Content-Length: 91

[Mon Oct 07 18:26:50.935946 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(140): [client 127.0.0.1:57073] mod_dumpio: dumpio_in [getline-blocking] 0 readbytes
[Mon Oct 07 18:26:50.935949 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(63): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): 2 bytes
[Mon Oct 07 18:26:50.935953 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(103): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT):

[Mon Oct 07 18:26:50.937521 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(140): [client 127.0.0.1:57073] mod_dumpio: dumpio_in [readbytes-blocking] 91 readbytes
[Mon Oct 07 18:26:50.937532 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(63): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): 91 bytes
[Mon Oct 07 18:26:50.937537 2024] [dumpio:trace7] [pid 19725:tid 19725] mod_dumpio.c(103): [client 127.0.0.1:57073] mod_dumpio:  dumpio_in (data-TRANSIENT): {"key_name": "NTP_SERVERS", "value": "98.139.133.27"}
[Mon Oct 07 18:26:50.937558 2024] [ssl:info] [pid 19725:tid 19725] [client 127.0.0.1:57073 {YRA:127.0.0.1:57073, YPA:127.0.0.1:57073}] AH02221: Requesting connection re-negotiation, referer: https://myapi.domain.com/api/healthcheck/

How can I make sure, perl script pass json data to the apache server? I tried setting Content-Type: application/json, that didnt work.

Perl search and replace words in file

Perl questions on StackOverflow

Published by Trey B on Wednesday 09 October 2024 17:01

I am not sure how to search and replace word from Perl.

I have .txt that contains image file names in random order.

Animals.txt

There is an image Dog_Image_85.jpg
Cat has an image Cat_Image_front.jpg
Here is another image Dog_Image_61.jpg
Cat has another image Cat_Image_back.jpg
Next image Dog_Image_55.jpg
Next Image Cat_Image_side.jpg
Next Image Dog_Image_200.jpg

I only want to change the Dog image names to a counter so it goes:

There is an image Dog_Image_1.jpg
Cat has an image Cat_Image_front.jpg
Here is another image Dog_Image_2.jpg
Cat has another image Cat_Image_back.jpg
Next image Dog_Image_3.jpg
Next Image Cat_Image_side.jpg
Next Image Dog_Image_4.jpg

I have tried these but I get an error each time:

#!/usr/local/bin/perl -w -I ../lib -I ./

use strict;

my $Animals = "Animals";

my $file = "$Animals.txt";

perl -pi -e 's/Dog_Image_.*.jpg/"Dog_Image_.++$i.jpg"/ge' $file;

This gives me an error: Can't use bareword perl.

I also tried with:

system('s/Dog_Image_.*.jpg/"Dog_Image_.++$i.jpg"/ge' $file);'

It still gives an error.

Syntax Error Using Double Quoted String and Fat Comma with map [duplicate]

Perl questions on StackOverflow

Published by Guido Flohr on Wednesday 09 October 2024 14:31

I have a syntax error in a Perl script that I don't understand:

# map BLOCK LIST
map { "/$_" => 1 } qw(foo bar baz);   # syntax error at .. line 1, near "} qw(foo bar baz)"

I have to rewrite it like this:

map { '/' . $_ => 1 } qw(foo bar baz);  # no error

This piece of code works on the other hand:

# Hash reference.
{ "/$_" => 1 };

I am using Perl 5.34.0.

TOTP with Perl and Authen::OATH

r/perl

Published by /u/pmz on Wednesday 09 October 2024 12:44

submitted by /u/pmz
[link] [comments]

Maintaining Perl 5 Core (Dave Mitchell): September 2024

Perl Foundation News

Published by alh on Wednesday 09 October 2024 07:35

Dave writes:

This is my monthly report on work done during September 2024 covered by my TPF perl core maintenance grant.

I spent most of last month continuing to do various bits of code refactoring and test-adding on Extutils::ParseXS, as a precursor to adding reference-counted stack (PERL_RC_STACK) abilities to XS.

SUMMARY:

5:02 process p5p mailbox
2:06 reduce smoke failures
54:15 refactor Extutils::ParseXS

Total: * 61:23 TOTAL (HH::MM)

How to create a parallel echo server using goroutines in SPVM?

dev.to #perl

Published by Yuki Kimoto on Wednesday 09 October 2024 05:59

How to create a parallel echo server using goroutines in SPVM?

I write a parallel echo server using SPVM::IO::Socket::IP and goroutines, channels, select in SPVM::Go.

See the following test code.

run_echo_server_go

Release of DateTime::Format::Intl

r/perl

Published by /u/jacktokyo on Wednesday 09 October 2024 02:45

I am quite thrilled to announce that after several months of hard work, I have released the perl module DateTime::Format::Intl. It mirrors its JavaScript equivalent of Intl.DateTimeFormat. The algorithm is quite elaborate, replicating how it works in web browsers. I also had to develop quite a few dependencies to make it work, notably Locale::Unicode and Locale::Unicode::Data, which provides access to all the Unicode CLDR (Common Locale Data Repository) data as an SQLite database via an extensive number of perl methods. I hope it will benefit you and supports you in the internationalisation of your projects in perl.

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Why The Perl and Raku Foundation Supports The Open Source Pledge

Perl Foundation News

Published by Stuart J Mackintosh on Tuesday 08 October 2024 11:00

The Open Source Pledge

We at The Perl and Raku Foundation are supporting the Open Source Pledge initiative.

The Open Source Pledge consists of companies with a shared commitment to paying the maintainers of the open source software they consume, therefore aims to help address sustainability challenges facing the Open Source community.

The Sustainability Challenge in OSS

Open source software is the backbone of much of today’s technology, but it relies heavily on the unpaid work of maintainers. As these volunteers struggle with burnout, turnover among OSS maintainers is high. Without the necessary support, key projects face the risk of disruption, which has far-reaching implications for the broader tech ecosystem. We have already seen the devastating effects of underfunded projects.

The Perl and Raku Foundation's Role in OSS

The Perl and Raku Foundation goal is to build a strong, healthy and sustainable language ecosystem and community. We also understand the importance of sustained funding for OSS projects. Through our community and core maintenance grants, we will provide support to developers who maintain essential infrastructure. These few dedicated individuals keep key components running, which are relied upon by both commercial systems and the broader internet.

This funding is necessary not only for technical upkeep but also for the non-technical aspects of managing open source communities. Without this support, the risk of losing essential contributors and the valuable work they do is too great.

This model of sustainability funding goes beyond just code contributions and aligns with the goals of the Open Source Pledge. It shows how financial support can be leveraged to maintain not just software, but entire developer ecosystems. This reinforces the importance of initiatives like the Open Source Pledge in supporting the broader open source ecosystem.

The Case for Joining the Pledge

The Open Source Pledge sets a new standard for how companies can contribute to OSS sustainability. By joining, companies commit to paying at least $2,000 per year for each developer on staff, with transparency through an annual report that details their payments.

We encourage other organizations to join us in supporting the Open Source Pledge, and using this as a method to set the value of your donations. By doing so, you’ll help ensure that the Perl and Raku ecosystem as well as the wider Open Source efforts remain healthy and sustainable, and that developers are recognized for the critical work they do. For more information about the Open Source Pledge and how to participate, please visit https://osspledge.com/

This is a welcome step in the right direction. "The Open Source Pledge is a crucial step towards ensuring the long-term sustainability of the open source ecosystem and by participating in this pledge, businesses can play a role in fostering innovation and maintaining the digital infrastructure we all rely on." Stuart Mackintosh, President of The Perl and Raku Foundation.

You can support The Perl and Raku Foundation directly using the method described by the Open Source Pledge, or any other amount that you can afford, details on our donations page here.

How to generate an executable file for an AI program using SPVM ?

dev.to #perl

Published by Yuki Kimoto on Tuesday 08 October 2024 04:59

Wouldn't you like to output a single executable file from your AI program? Then, you can run the AI program just by copying the executable file to the Raspberry Pi. Here's how to achieve this using SPVM. Here's an example of image recognition using MINIST as an example of AI using deep learning.

SPVM program

This is an AI program to recognize images using MINIST data.

It is writen by SPVM and SPVM::R.

Install dependent modules.

cpanm SPVM
cpanm SPVM::Errno
cpanm SPVM::File::Basename
cpanm SPVM::File::Spec
cpanm SPVM::FindBin
cpanm SPVM::Math
cpanm SPVM::Regex
cpanm SPVM::Sys
cpanm SPVM::Time::Local
cpanm SPVM::Time::Piece
cpanm SPVM::IO
cpanm SPVM::R

Execute an SPVM program.

spvm -I network_lib/SPVM my_minist_app.spvm

Generate an executable file and execute it.

spvmcc -I network_lib/SPVM -o my_minist_app my_minist_app.spvm

./my_minist_app

I'm not an AI expert, but if you are, I think you can modify this.

If you're interested in parallelization using threads and goroutines, see also:

Improving in perl

r/perl

Published by /u/Recent-Astronaut-240 on Monday 07 October 2024 13:58

Hey, I am writting in perl since few years I have written lots of stuff over the years however would consider myself more beginner, I love syntax and the fact that perl is almost on every linux. My main usecase is system scripting/parallelizing tasks/ some API clients.

I have felt in love threads::queue and inotify2 implementation and use them very frequently.

Module management - What is more nowadays standard to manage them?

I use cpan, or download module from cpan and execute perl makefile or later generated C Makefile.

However sometimes struggle:

Last example that comes to my mind:

I want to create simple app that interacts with cassandra and any module I try to gather is based on deprecated IO::Sockets::INET6 - also have disabled ipv6 and not able to build it. Is there any package manager that ships modules in some more portable formats?

If I build module that for example needs some .so that is bound to kABI [Inotify2] I push them to system perllib path. I understand that it is based on kABI and need to recompile with kernel-headers. But is there any more portable solution. My feeling is that on python side managing pkgs with pip is easier.

EDIT:

Shipping modules with APP, Is there like any equavilent for python-venv?

Is there any not code related method?

So far I use:

use FindBin; use lib "$FindBin::Bin/lib";

And bundle them locally.

Object model:

I tried writting OOP in pure perl and blessing every constructor seems strange for me.

I heard about Moo and Moose - are they still activly used? Are they simple to use for simple scripts?

Web development

Which frameworks are most popular nowadays? Do not have much requirements only MVC support and maybe some simple templating engine. Just for some small simple dashboards, project sites.

Web SAPI - How is invoked modern perl webapplication - apache mod_perl? Standalone perl? What is modern approach?

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