Beefy Boxes and Bandwidth Generously Provided by pair Networks
Your skill will accomplish
what the force of many cannot
 
PerlMonks  

Cool Uses for Perl

( #1044=superdoc: print w/replies, xml ) Need Help??

This section is the place to post your general code offerings -- everything from one-liners to full-blown frameworks and apps.

CUFP's
Perl Tk run on Android. It works
1 direct reply — Read more / Contribute
by zentara
on Sep 17, 2019 at 13:46
    Hi,this is a step by step guide, but your experience might differ.

    I am using Android 7.0 Nitrogen on a Nexus 7.

    (1) Go to google play store and install the termux app. Now follow the instructions for setting up a graphical environment at termux gui. I suggest using the tigervnc as the XSDL dosn't work on Android later than v4. Also install the VNC Viewer app. The instructions explain how to setup fluxbox and openbox but I had trouble getting them to load. The default TWM works fine. Basically the commands until now should be "pkg install x11-repo" followed by "pkg install tigervnc aterm"

    (2) Install the cc with "pkg install clang libxorgproto" I found that X11/X.h file was in libxorgproto and is needed.

    (3) While in termux, and at the prompt "pkg install mc" to naviagte and edit :-). Create and edit the file ~/.bashrc and add export DISPLAY=":1"

    (4) Edit the ~/.vnc/xstartup file to say this:
    ##########################
    aterm -geometry 80x24+10+150 -ls &
    twm &
    ###########################

    At the termux prompt, type "vncserver -localhost" and you should get a message saying :1 was started. If not do a "killall Xvnc" and try again. Once you are running, start the VNC Viewer app and enter 127.0.0.1:5901 for address. 5900 + display number

    You should see a black screen in your VNC Viewer with an aterm. In the aterm type "pkg install perl" then "pkg install Tk".

    The Japanese fonts don't seem to work, and the test takes long, but the Tk windows are opening.

    You may find that cpan's install fails at make test, so then just navigate to ~/.cpan/build/Tk-****/ and type "make install". Then you will find that the shebang line #!/usr/bin/perl needs to be symlinked or changed to /data/data/com.termux/files/usr/bin/perl. YMMV. As an easy solution, just start all Tk programs like "perl mytkapp"

    Good luck, have fun. Perl Tk is way easier than Android programming. :-)


    I'm not really a human, but I play one on earth. ..... an animated JAPH
Graphics::Framebuffer + MCE::Hobo and threads
No replies — Read more | Post response
by marioroy
on Sep 09, 2019 at 02:25

    Greetings,

    I'm posting to share something wonderful. MCE and MCE::Shared have reached 1.850. They now work reliably with Graphics::Framebuffer. Three new examples were added to the framebuffer folder on GitHub. Curently, Graphics::Framebuffer works on Linux maybe FreeBSD. The 3 examples many_boxes.pl, many_ellipses.pl, and many_lines.pl use MCE::Hobo, threads (yes this too), and MCE::Child respectively.

    I also updated the PDL demonstration on GitHub, recently. That works on Windows similarly to runing on UNIX.

    Me ka aloha pumehana (kind regards), Mario

simple game of life by new hand
4 direct replies — Read more / Contribute
by glycine
on Sep 08, 2019 at 05:42

    hello! when I first read some things about game of life, it let me amazing. some days ago, suddenly, I find maybe I can make one by my self with perl! although there are a lot of game of life on the internet, wrote by Rust, c++, java... but I think it will be a interesting practice, so I write this :) ( Conway's Game of Life on the Wiki: Conway's Game of Life )

    this code can't be expand to other rules of cell automata, and have a lot of pointless subroutine.

    here is code:

    new: after roboticus give me advice, I change the name of variables and subroutines, delete a bug, so, here is new version.

    I know that using OOP is better, but I am still learning about this, um... I will try it...

    thanks you for read this! p.s., I try to use readmore, but I don't know it if work in preview...

Lexing C++
3 direct replies — Read more / Contribute
by Random_Walk
on Aug 31, 2019 at 19:17

    So folks,

    today I need to makes some sense of C++ files. I will need to parse out function signatures, and I have tried this with regex before, it gets messy especially around templates. Now a similar requirement has reared it's head so step one, lex the code. without further ado here is my attempt at lexing C++. The Lexer is called with an open file handle to a C++ source file. This is lexed into an array of tokens, that is then handed on to the parser.

    What do you think, is this going to give me a nice labeled stream and make parsing a dream, or am I stumbling into know gotchas? Does it qualify as cool?

    Cheers,
    R.

    Pereant, qui ante nos nostra dixerunt!

    Update

    More compiler directives added
perl2c++.pl (I know Kung Fu)
1 direct reply — Read more / Contribute
by Anonymous Monk
on Aug 30, 2019 at 05:25
    Downloaded:
    https://github.com/gmatht/joshell/blob/master/scripts/perl2c%2B%2B.pl
    
    
    Saved as hw.pl:
    #!/usr/bin/perl my $h = "hello"; my $w = "world"; for (my $i = 0; $i < 3; $i++) { print "$h $w \n"; } my $n = 0; my $x = 100000000; for (my $i = 0; $i < $x; $i++) { $n++; } print "\n"; print "Counted to $n \n";
    Typed:
    perl perl2c++.pl < hw.pl | tee hw.cpp && g++ hw.cpp -o hw.o && time pe +rl hw.pl && time hw.o
    Creating:
    #include <iostream> int main(){ //!/usr/bin/perl std::string h("hello"); std::string w("world"); for (double i=0; i < 3; i++) { std::cout << "" << h << " " << w << " \n"; } double n=0; double x=100000000; for (double i=0; i < x; i++) { n++; } std::cout << "\n"; std::cout << "Counted to " << n << " \n"; return 0; }
    Observed discrepancy:
    perl	0m3.213s
    c++	0m0.298s
    
    Cool use for Perl, to learn a little C++!
Moving, copying and renaming files with new tool
2 direct replies — Read more / Contribute
by siberia-man
on Aug 14, 2019 at 05:22
    Hello Monks,

    I re-invented the wheel and decided to share it. This is script that is supposed to be used as a tool for moving, copying and renaming files. In the beginning I called it as "the re-invented wheel" becuase there are a few implementations for such kind of functionality. I found 3 of them at least (all are mentioned in the documentation). While developing the script I borrowed some good ideas from those implementations and adapted for my script. And I applied my vision of the conveniency.

    Here I show some scenarios from real life I've really met:

    Removing prefixes and suffixes:

    file-rename 's/^[^.]+\.//; s/\.[^.]+$//' ...
    Enumerate files:
    file-rename 's/^/sprintf "%02d. ", $NR/' ...

    By default the script implements move files, but it is possible to copy them with the option -c, --copy.

    It is posible to include/exclude Perl modules with the option -M for those cases it you need to apply something very specific. It is similar to Perl's own option.

    With the -T or --transcode option it is possible to apply encoding over names. For example the following example works fine for filenames in Cyrillic with Perl 5.14 under Cygwin 1.7.25:

    file-rename -Tutf8 '$_ = ucfirst' -f ...

    Handling with filename component is enabled with the option -N, --filename-only. The is example (prepending filenames with some prefix):

    file-rename 's/^/old-/' -N ../*

    Verbosity, forcing and dry-run are implemented with the -v, -f and -n options, respectively. The long options are also available

    I have still never met the case of using the zero-terminated lines but implemented it with the options -z, -0, --null.

    The last thing I developed is renaming in loop with the option -r, --rename. With this option we can:

    Rotate files cyclically to left (resulting to file2 file3 file4 file1):

    file-name --rename=rotate-left file1 file2 file3 file4
    Rotate files cyclically to right (resulting to file4 file1 file2 file3):
    file-name --rename=rotate-right file1 file2 file3 file4
    Swap pair of files (swap nearest, resulting to file2 file1 file4 file3):
    file-name --rename=swap file1 file2 file3 file4
    Flip the whole list of files (swap farthest, resulting to file4 file3 file2 file1):
    file-name --rename=flip file1 file2 file3 file4

    The script lives in github. Below is the latest version to the moment of the writing.

Animated Heatmap
3 direct replies — Read more / Contribute
by Anonymous Monk
on Aug 10, 2019 at 08:52
New stable MCE 1.842 and MCE::Shared 1.842 releases
No replies — Read more | Post response
by marioroy
on Jul 21, 2019 at 23:13

    Update: Added results for Parallel::ForkManager 2.02. The results mentioned in the POD documentation ran slower due to an unaware background job at the time. I reran again on all 5 platforms.

    Dear fellow Monks,

    I am pleased to annouce MCE 1.842 and MCE::Shared 1.842 (both stable). MCE now includes MCE::Channel and MCE::Child recently.

    This weekend, added Parallel::ForkManager-like demonstration to the POD section in MCE::Child and MCE::Hobo. The results were captured on a Macbook Pro (late 2013 model - 2.6 GHz ~ 3.6 GHz with Turbo Boost).

    To run, one may direct standard output to :nul or /dev/null depending on the platform. Or better yet, I commented out the print line in the on_finish handler. Unfortunately, Parallel::ForkManager 2.02 suffers from memory leaks on the Windows platform ($^O eq 'MSWin32') and the reason why slower than Cygwin.

    These days, there are other ways and instead have workers persist (i.e. pull items from a shared queue or channel) or perhaps via MCE's input and chunking capabilities.

    Regards, Mario

2d field of view, vision algorithm in grid (ray casting)
1 direct reply — Read more / Contribute
by Discipulus
on Jun 24, 2019 at 15:05
    Hello community!

    who knows me is aware I'm writing a game (engine?) and I asked here for the precious monks wisdom about circular area in a coordinates grid (AoA).

    But now I'm progressing and I discovererd that the above illuminate function is not enough. I found a big resource of Roguelike_Vision_Algorithms and I choosed the simplest one (second example) and I ported it to Perl ( field_of_view sub in the below code ).

    Impressed by this shiny exemple I wrapped into an interactive program to show my proof of concept:

    Chatting in the perl irc channel daxim also implemented a semi-transparency feature I'd like to add to my game. Here daxim's patch (and a big thank to him):

    have fun!

    L*

    There are no rules, there are no thumbs..
    Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.
Listener Crossword #4321 solitaire
No replies — Read more | Post response
by GrandFather
on Jun 21, 2019 at 06:19

    The Times newspaper features an occasional "The Listener Crossword" which is in fact a numerically based logic puzzle in the form of a crossword. A friend of mine introduced me to the genera with #4321 which is a puzzle of two parts. The first part consists of populating the playing grid with hexadecimal numbers. The second part consist of using the populated grid to play a game of solitaire which, when played correctly on a correctly constructed grid ends up spelling out three words. There is a certain amount of trial and error involved in finding the solution!

    So to aid playing the game in the second part of the puzzle I wrote the following script. The gameGrid is configured for a partial solution of the game. A feature of the code is that you can "save" the game state at any point then paste the saved gameGrid in place of the current grid to explore possibilities from that point.

    As far as I can tell developing tools of this sort is all part of the solution domain for the puzzle. They are very much one off puzzles as each "crossword" is a puzzle of a completely different nature, so it is very unlikely that this tool will be useful for another "Crossword Puzzle". But it is a cool use for Perl!

    Note that a few shortcuts have been taken in the code. In particular global variables are used, which I usually avoid. The rendered grid is not very pretty and the layout generally is rough, but good enough for the task at hand.

    Play consists of clicking on a "peg" (piece to be moved) then an "empty" cell ("_") skipping over one intervening piece. The skipped piece is removed and added to the "skipped" string. Moves can be undone back to the starting state. For instructions beyond these you will need to find the original puzzle instructions and create the starting grid.

    Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond
Tk ASCII Draw on Canvas
4 direct replies — Read more / Contribute
by Discipulus
on Jun 03, 2019 at 06:57
    Hello folks!,

    another Tk CUFP from my part! It is working and is also a draft for a bigger project (you all know what I'm working on nowadays.. ;)

    This is an ASCII drawing program expoiting the best I'm able to from Canvas and their precious feature: tags.

    I left some commented code because I have some question in case some Tk expert has answers:

    -1 about binding modifiers: I planned the draw action when <Button1-Motion> is on: ie. when button 1 is pressed (modifier) and the pointer is moveing over the Canvas. No luck. The program below now uses <Control-Motion> and perhaps is even better (less mouse->less pain)

    -2 I noticed some strange behaviours with some key: £ aka sterling in Tk world and ° aka degree if I use one of them (now commented in the code) I get back a multichar: uppercase A with caret above plus the degree symbol, for instance.

    -3 I wonder how can I implement an export coordinates range in my Canvas: something like: when SHIFT modifier is on and Motion is on too I should tag tiles with something like selceted use a different color for them and haveing two buttons for export corrdinates and select nothing Seems this the right way?

    PS now you can draw fancy things like:

    L*

    There are no rules, there are no thumbs..
    Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.
Coordinate validator
2 direct replies — Read more / Contribute
by timpoiko
on May 17, 2019 at 05:41
    Dear monks. Some years ago I write small program which can validate coordinates (locations on the Earth) from user input. I didn't to restrict format of input and I wanted support English as well as Finnish.
perl 2.01 on Cygwin
3 direct replies — Read more / Contribute
by rje
on Mar 26, 2019 at 19:02

    Even though I haven't programmed in C for a long time, I could get Perl2 compiled and running (a 387k binary!) in just a couple hours this afternoon on Cygwin.

    .Can I throw out the in-house malloc and other hand-rolled memory management code? What else can I do away with? How about all of the variant hardware #defines Larry had to make? Can't I simplify the code by aiming for one modern OS (Linux?) and Dockerizing it? And how about all that K&R C? Boy does that take me back... Can I shrink the binary by modernizing the code?

    $ perl2 -v This is perl 2, subversion 1 (v2.0.1) Copyright 1987-2019, Larry Wall Perl may be copied only under the terms of either the Artistic License or the GNU GPL (https://www.gnu.org/licenses/gpl.html). Documentation for Perl should be found on this system via "man perl". Point your browser at http://www.perl.org/, the Perl Home Page. Patch level: 0

    I needed GCC, make, and byacc (softlinked to 'yacc'). Then, I had to make a few edits:

    1. stab.c: commented out extern errno and replaced it with: int errno;

    2. perl.h: commented out the #ifdef that declared sprintf().

    3. perl.h: commented out the declaration of times().

    4. perly.c: I changed the -v message to look more Perl-like.

    I might have made two earlier edits, but they were along the same lines of removing conflicting or redundant declarations.

    And now, as a reward, I've got perl 2 running on Cygwin on my laptop! I have to say, it was worth the effort!

    Onward to hack!

    -rwxrwxr-x+ 1 rje None 387058 Mar 26 17:52 perl2.exe
Multiplication digit persistence
4 direct replies — Read more / Contribute
by tobyink
on Mar 21, 2019 at 09:17

    Try to find a number that takes more than eleven steps.

    use v5.10; use strict; use warnings; use List::Util qw(product); sub per { my ($n) = @_; return if $n < 10; my $p = product split //, $n; return $p, per($p); } my @steps = per 277777788888899; my $steps = @steps; say "$steps steps"; say for @steps;
Conversions of SI Units
1 direct reply — Read more / Contribute
by choroba
on Feb 16, 2019 at 16:57
    My son (11) has just learned SI units and their prefixes at school. They started just with metres and litres, only some of the prefixes (mili, centi, deci, hecto, kilo) and they don't know the floating point yet. Because of his broken arm, he missed several days at school and needed to practice. So, I've written a Tk application for him to practice. It takes one parameter, the number of formulas to generate.

    Feel free to localize it using the constants at the beginning. Adding the floating point left as an exercise for the reader.

    It's been a practice for me, too, because of Function::Parameters.

    map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

Add your CUFP
Title:
CUFP:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others surveying the Monastery: (7)
    As of 2019-09-23 15:23 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?
      The room is dark, and your next move is ...












      Results (280 votes). Check out past polls.

      Notices?