Perl 6 iterate through command line arguments












8














I want to write a Perl 6 program that performs the same operation on an undetermined number of files, just like how you can use rm file1.txt file2.txt file3.txt in Linux.



My code looks like this:



#!/usr/bin/env perl6


my @args = @*ARGS.perl;

for @args -> $arg {
say $arg
}


However, when I invoke it as ./loop_args.pl6 file1.txt file2.txt I get the following output: ["file1.txt", "file2.txt"]



What am I doing wrong? I just want it to be an array.










share|improve this question






















  • I would like to know what lead you to use .perl, so that we can prevent others from going down this path in the future.
    – Brad Gilbert
    Nov 16 '18 at 16:07










  • Hey Brad, I misread the documentation here; I have a bad habit of only looking at the code: perl6maven.com/parsing-command-line-arguments-perl6
    – Taylor Lee
    Nov 16 '18 at 23:28












  • Ok. Short of asking Gabor to change that article, I suppose there's not much to do.
    – Brad Gilbert
    Nov 16 '18 at 23:41
















8














I want to write a Perl 6 program that performs the same operation on an undetermined number of files, just like how you can use rm file1.txt file2.txt file3.txt in Linux.



My code looks like this:



#!/usr/bin/env perl6


my @args = @*ARGS.perl;

for @args -> $arg {
say $arg
}


However, when I invoke it as ./loop_args.pl6 file1.txt file2.txt I get the following output: ["file1.txt", "file2.txt"]



What am I doing wrong? I just want it to be an array.










share|improve this question






















  • I would like to know what lead you to use .perl, so that we can prevent others from going down this path in the future.
    – Brad Gilbert
    Nov 16 '18 at 16:07










  • Hey Brad, I misread the documentation here; I have a bad habit of only looking at the code: perl6maven.com/parsing-command-line-arguments-perl6
    – Taylor Lee
    Nov 16 '18 at 23:28












  • Ok. Short of asking Gabor to change that article, I suppose there's not much to do.
    – Brad Gilbert
    Nov 16 '18 at 23:41














8












8








8







I want to write a Perl 6 program that performs the same operation on an undetermined number of files, just like how you can use rm file1.txt file2.txt file3.txt in Linux.



My code looks like this:



#!/usr/bin/env perl6


my @args = @*ARGS.perl;

for @args -> $arg {
say $arg
}


However, when I invoke it as ./loop_args.pl6 file1.txt file2.txt I get the following output: ["file1.txt", "file2.txt"]



What am I doing wrong? I just want it to be an array.










share|improve this question













I want to write a Perl 6 program that performs the same operation on an undetermined number of files, just like how you can use rm file1.txt file2.txt file3.txt in Linux.



My code looks like this:



#!/usr/bin/env perl6


my @args = @*ARGS.perl;

for @args -> $arg {
say $arg
}


However, when I invoke it as ./loop_args.pl6 file1.txt file2.txt I get the following output: ["file1.txt", "file2.txt"]



What am I doing wrong? I just want it to be an array.







perl6






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 13 '18 at 1:49









Taylor Lee

432




432












  • I would like to know what lead you to use .perl, so that we can prevent others from going down this path in the future.
    – Brad Gilbert
    Nov 16 '18 at 16:07










  • Hey Brad, I misread the documentation here; I have a bad habit of only looking at the code: perl6maven.com/parsing-command-line-arguments-perl6
    – Taylor Lee
    Nov 16 '18 at 23:28












  • Ok. Short of asking Gabor to change that article, I suppose there's not much to do.
    – Brad Gilbert
    Nov 16 '18 at 23:41


















  • I would like to know what lead you to use .perl, so that we can prevent others from going down this path in the future.
    – Brad Gilbert
    Nov 16 '18 at 16:07










  • Hey Brad, I misread the documentation here; I have a bad habit of only looking at the code: perl6maven.com/parsing-command-line-arguments-perl6
    – Taylor Lee
    Nov 16 '18 at 23:28












  • Ok. Short of asking Gabor to change that article, I suppose there's not much to do.
    – Brad Gilbert
    Nov 16 '18 at 23:41
















I would like to know what lead you to use .perl, so that we can prevent others from going down this path in the future.
– Brad Gilbert
Nov 16 '18 at 16:07




I would like to know what lead you to use .perl, so that we can prevent others from going down this path in the future.
– Brad Gilbert
Nov 16 '18 at 16:07












Hey Brad, I misread the documentation here; I have a bad habit of only looking at the code: perl6maven.com/parsing-command-line-arguments-perl6
– Taylor Lee
Nov 16 '18 at 23:28






Hey Brad, I misread the documentation here; I have a bad habit of only looking at the code: perl6maven.com/parsing-command-line-arguments-perl6
– Taylor Lee
Nov 16 '18 at 23:28














Ok. Short of asking Gabor to change that article, I suppose there's not much to do.
– Brad Gilbert
Nov 16 '18 at 23:41




Ok. Short of asking Gabor to change that article, I suppose there's not much to do.
– Brad Gilbert
Nov 16 '18 at 23:41












2 Answers
2






active

oldest

votes


















8














For Perl6 the arguments array is @*ARGS, this gives the code:



#! /usr/bin/env perl6

use v6;

for @*ARGS -> $arg
{
print("Arg $argn");
}


So you just need to remove the .perl from your my @args = @*ARGS.perl; line.



EDIT: Updated as per Ralphs's comments






share|improve this answer























  • You don't need the use strict; there :)
    – Scimon
    Nov 13 '18 at 9:04






  • 2




    To clarify @Scimon's comment you don't need the use strict; because P6 defaults to strict. While I'm writing a comment I'll also note that the my $arg; declares a $arg but it's redundant and misleading. The -> $arg declares another $arg that shadows the my one inside the block.
    – raiph
    Nov 13 '18 at 19:24





















5














So it depends on what you want to do with the files. If you want to read through them all you might want to take a look at $*ARGFILES this is an IO::CatHandle Object that batches up all the arguments and treats them as a list of files. So to print them all out you could do.



#! /usr/bin/env perl6
use v6;

for $*ARGFILES.handles -> $IO {
$IO.path.say
}


Ok so that's a bit more convoluted than looking at @*ARGS. But what if you wanted to print the first 5 lines for each file?



#! /usr/bin/env perl6
use v6;

for $*ARGFILES.handles -> $IO {
say $IO.lines: 5;
}


Or maybe you just want to read the contents of all the files and print them out?



#! /usr/bin/env perl6
use v6;

.say for $*ARGFILES.lines;


Hope that gives you some ideas.






share|improve this answer





















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    2 Answers
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    2 Answers
    2






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    8














    For Perl6 the arguments array is @*ARGS, this gives the code:



    #! /usr/bin/env perl6

    use v6;

    for @*ARGS -> $arg
    {
    print("Arg $argn");
    }


    So you just need to remove the .perl from your my @args = @*ARGS.perl; line.



    EDIT: Updated as per Ralphs's comments






    share|improve this answer























    • You don't need the use strict; there :)
      – Scimon
      Nov 13 '18 at 9:04






    • 2




      To clarify @Scimon's comment you don't need the use strict; because P6 defaults to strict. While I'm writing a comment I'll also note that the my $arg; declares a $arg but it's redundant and misleading. The -> $arg declares another $arg that shadows the my one inside the block.
      – raiph
      Nov 13 '18 at 19:24


















    8














    For Perl6 the arguments array is @*ARGS, this gives the code:



    #! /usr/bin/env perl6

    use v6;

    for @*ARGS -> $arg
    {
    print("Arg $argn");
    }


    So you just need to remove the .perl from your my @args = @*ARGS.perl; line.



    EDIT: Updated as per Ralphs's comments






    share|improve this answer























    • You don't need the use strict; there :)
      – Scimon
      Nov 13 '18 at 9:04






    • 2




      To clarify @Scimon's comment you don't need the use strict; because P6 defaults to strict. While I'm writing a comment I'll also note that the my $arg; declares a $arg but it's redundant and misleading. The -> $arg declares another $arg that shadows the my one inside the block.
      – raiph
      Nov 13 '18 at 19:24
















    8












    8








    8






    For Perl6 the arguments array is @*ARGS, this gives the code:



    #! /usr/bin/env perl6

    use v6;

    for @*ARGS -> $arg
    {
    print("Arg $argn");
    }


    So you just need to remove the .perl from your my @args = @*ARGS.perl; line.



    EDIT: Updated as per Ralphs's comments






    share|improve this answer














    For Perl6 the arguments array is @*ARGS, this gives the code:



    #! /usr/bin/env perl6

    use v6;

    for @*ARGS -> $arg
    {
    print("Arg $argn");
    }


    So you just need to remove the .perl from your my @args = @*ARGS.perl; line.



    EDIT: Updated as per Ralphs's comments







    share|improve this answer














    share|improve this answer



    share|improve this answer








    edited Nov 13 '18 at 21:32

























    answered Nov 13 '18 at 2:14









    Kingsley

    2,26011023




    2,26011023












    • You don't need the use strict; there :)
      – Scimon
      Nov 13 '18 at 9:04






    • 2




      To clarify @Scimon's comment you don't need the use strict; because P6 defaults to strict. While I'm writing a comment I'll also note that the my $arg; declares a $arg but it's redundant and misleading. The -> $arg declares another $arg that shadows the my one inside the block.
      – raiph
      Nov 13 '18 at 19:24




















    • You don't need the use strict; there :)
      – Scimon
      Nov 13 '18 at 9:04






    • 2




      To clarify @Scimon's comment you don't need the use strict; because P6 defaults to strict. While I'm writing a comment I'll also note that the my $arg; declares a $arg but it's redundant and misleading. The -> $arg declares another $arg that shadows the my one inside the block.
      – raiph
      Nov 13 '18 at 19:24


















    You don't need the use strict; there :)
    – Scimon
    Nov 13 '18 at 9:04




    You don't need the use strict; there :)
    – Scimon
    Nov 13 '18 at 9:04




    2




    2




    To clarify @Scimon's comment you don't need the use strict; because P6 defaults to strict. While I'm writing a comment I'll also note that the my $arg; declares a $arg but it's redundant and misleading. The -> $arg declares another $arg that shadows the my one inside the block.
    – raiph
    Nov 13 '18 at 19:24






    To clarify @Scimon's comment you don't need the use strict; because P6 defaults to strict. While I'm writing a comment I'll also note that the my $arg; declares a $arg but it's redundant and misleading. The -> $arg declares another $arg that shadows the my one inside the block.
    – raiph
    Nov 13 '18 at 19:24















    5














    So it depends on what you want to do with the files. If you want to read through them all you might want to take a look at $*ARGFILES this is an IO::CatHandle Object that batches up all the arguments and treats them as a list of files. So to print them all out you could do.



    #! /usr/bin/env perl6
    use v6;

    for $*ARGFILES.handles -> $IO {
    $IO.path.say
    }


    Ok so that's a bit more convoluted than looking at @*ARGS. But what if you wanted to print the first 5 lines for each file?



    #! /usr/bin/env perl6
    use v6;

    for $*ARGFILES.handles -> $IO {
    say $IO.lines: 5;
    }


    Or maybe you just want to read the contents of all the files and print them out?



    #! /usr/bin/env perl6
    use v6;

    .say for $*ARGFILES.lines;


    Hope that gives you some ideas.






    share|improve this answer


























      5














      So it depends on what you want to do with the files. If you want to read through them all you might want to take a look at $*ARGFILES this is an IO::CatHandle Object that batches up all the arguments and treats them as a list of files. So to print them all out you could do.



      #! /usr/bin/env perl6
      use v6;

      for $*ARGFILES.handles -> $IO {
      $IO.path.say
      }


      Ok so that's a bit more convoluted than looking at @*ARGS. But what if you wanted to print the first 5 lines for each file?



      #! /usr/bin/env perl6
      use v6;

      for $*ARGFILES.handles -> $IO {
      say $IO.lines: 5;
      }


      Or maybe you just want to read the contents of all the files and print them out?



      #! /usr/bin/env perl6
      use v6;

      .say for $*ARGFILES.lines;


      Hope that gives you some ideas.






      share|improve this answer
























        5












        5








        5






        So it depends on what you want to do with the files. If you want to read through them all you might want to take a look at $*ARGFILES this is an IO::CatHandle Object that batches up all the arguments and treats them as a list of files. So to print them all out you could do.



        #! /usr/bin/env perl6
        use v6;

        for $*ARGFILES.handles -> $IO {
        $IO.path.say
        }


        Ok so that's a bit more convoluted than looking at @*ARGS. But what if you wanted to print the first 5 lines for each file?



        #! /usr/bin/env perl6
        use v6;

        for $*ARGFILES.handles -> $IO {
        say $IO.lines: 5;
        }


        Or maybe you just want to read the contents of all the files and print them out?



        #! /usr/bin/env perl6
        use v6;

        .say for $*ARGFILES.lines;


        Hope that gives you some ideas.






        share|improve this answer












        So it depends on what you want to do with the files. If you want to read through them all you might want to take a look at $*ARGFILES this is an IO::CatHandle Object that batches up all the arguments and treats them as a list of files. So to print them all out you could do.



        #! /usr/bin/env perl6
        use v6;

        for $*ARGFILES.handles -> $IO {
        $IO.path.say
        }


        Ok so that's a bit more convoluted than looking at @*ARGS. But what if you wanted to print the first 5 lines for each file?



        #! /usr/bin/env perl6
        use v6;

        for $*ARGFILES.handles -> $IO {
        say $IO.lines: 5;
        }


        Or maybe you just want to read the contents of all the files and print them out?



        #! /usr/bin/env perl6
        use v6;

        .say for $*ARGFILES.lines;


        Hope that gives you some ideas.







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 13 '18 at 9:12









        Scimon

        1,5541010




        1,5541010






























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