use v6.c;

use Universal::Errno::Constants;

use NativeLibs:ver<0.0.5+>;
use NativeCall;

class locale_t is repr('CPointer') {}

my sub freelocale(locale_t $locale) is native { ... }

my sub newlocale(int32 $mask, Str $locale, int32 $base) returns locale_t is native { ... }

my sub strerror_l(int32 $errno, locale_t $locale) returns Str is native { ... }

# POSIX version
my sub strerror_r(int32 $errno, Pointer $buf, size_t $len) returns int32 is native { ... }

my constant CLIB = $*KERNEL.name eq 'darwin'
  ?? 'libSystem.B.dylib'
  !! NativeLibs::Searcher.at-runtime(
    'c',
    'errno',
    1..100 # This range should cover all BSDs and Linux for a long time.
  );

my int $last_set = 0;
my int $last_seen_native
  = my $ERRNO := cglobal(CLIB, "errno", int32);

my class errno {
    method !index() {
        my int $errno_now = $ERRNO;
        $last_set = $last_seen_native = $errno_now
          if $last_seen_native != $errno_now;
        $last_set
    }
    method Str(--> Str:D)  {
      return strerror_compat(self!index);
    }
    method gist(--> Str:D) {
        if self!index -> $index {
          "{self.Str} (errno = $index)"
        }
        else {
            ""
        }
    }
    method Numeric(--> Int:D) { self!index }
    method symbol(--> Errno:D) { Errno(self.Numeric) }
}

# strerror is not threadsafe, so it is not usable in Raku.
# strerror_r has two different versions, one POSIX, and one GNU.
# strerror_l is a POSIX standard, but macos and dragonflybsd do not implement it. GNU and musl do.
# To implement this properly, attempt to call strerror_l. If that fails, use strerror_r.
# GNU-specific strerror_r will never be called, so this is fully portable.

# Ugly compat function
sub strerror_compat(int32 $errno) returns Str:D is inlinable {
  my $current_errno = Errno($errno);
  my $locale = newlocale(0, "C", 0);
  die "While handling error of type {$current_errno}, another error occurred:\n {errno.symbol}" unless $locale ~~ locale_t;
  my Str:D $error = "";
  {
    $error = "" ~ strerror_l($errno, $locale);
    CATCH {
      freelocale($locale);
      $error = "" ~ strerror_ugly($errno);
      return $error;
    }
  }
  freelocale($locale);
  $error;
}

sub strerror_ugly(int32 $errno) returns Str {
  my buf8 $buf .= allocate(1024, 0);
  my $res;
  while ( $res = strerror_r($errno, nativecast(Pointer, $buf), $buf.elems) ) != 0 {
    if $res < 0 {
      if errno.symbol ~~ EINVAL {
        return "Unknown error {$errno}";
      }
    }
    elsif Errno($res) ~~ EINVAL {
      return "Unknown error {$errno}";
    }
    # Handle ERANGE error
    $buf.reallocate($buf.elems * 2, 0);
  }
  return $buf.decode;
}


module Universal::Errno::Unix {
    my $proxy := Proxy.new(
      FETCH => -> $ { UNIT::errno },
      STORE => -> $, $value { set_errno($value) }
    );

    my sub errno() is export is raw { $proxy }
    my sub set_errno(Int() $value) is export is raw {
        $last_seen_native = $ERRNO;  # ignore any changes until now
        $last_set = $value;
        $proxy
    }

    # sub strerror added by Travis Gibson
    my sub strerror(Int() $value --> Str) is export is raw {
      strerror_compat($value);
    }
}



head

Unix::errno - Provide transparent access to errno


use Unix::errno;  # exports errno, set_errno


say errno;              # No such file or directory (errno = 2)
say "failed: {errno}";  # failed: No such file or directory
say +errno;             # 2


This module provides access to the C<errno> variable that is available on
all Unix-like systems.  Please note that in a threaded environment such as
Perl 6 is, the value of C<errno> is even more volatile than it has been
already.  For now, this issue is ignored.


Since setting of any "extern" variables is not supported yet by C<NativeCall>,
the setting of C<errno> is faked.  If C<set_errno> is called, it will set
the value only in a shadow copy.  That value will be returned As long as
the underlying "real" errno doesn't change (at which point that value
will be returned.


Source can be located at: https://github.com/lizmat/Unix-errno . Comments and
Pull Requests are welcome.


This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.


root

Windows

Constants

React

=begin React :component<HeaderCol> :id<menu> 
=para L<Documentation|/doc/introduction>
=para L<Modules| /mods>
=para L<Examples| file:../examples/index.podlite>
=para L<Download |file:../download/index.podlite>
=para L<About|file:../about/index.podlite>
=para 🔍 K<⌘K>/K<ctrl-K>
=end React


=begin React :component<HeaderCol> :id<footer>  
=begin nested :!nested
=item1 B<Language>
    =item2 L<Get started|file:../getting-started/getting-started.podlite>
    =item2 L<Why Raku?|/doc/language/faq#Why-should-I-learn-Raku-What's-so-great-about-it>
    =item2 L<Try Raku|https://glot.io/new/raku>
    =item2 L<Raku cheat sheet|https://github.com/Raku/mu/blob/master/docs/Perl6/Cheatsheet/cheatsheet.txt>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<Raku on Exercism|https://exercism.org/tracks/raku>
    =item2 L<Wikipedia|https://en.wikipedia.org/wiki/Raku_(programming_language)>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=begin nested :!nested

=item1 B<L<Documentation|/doc>>
    =item2 L<Getting started, Migration guides from other languages, & Tutorials | file:../doc/introduction.podlite>
    =item2 L<Language References|file:../doc/reference.podlite>
    =item2 L<Type Reference| file:../doc/types.podlite>
    =item2 L<Miscellaneous| file:../doc/miscellaneous.podlite>
    =item2 L<FAQs (Frequently Asked Questions)|/doc/language/faq>
    =item2 L<Community|/doc/language/community>
    =item2 L<The list of all documents|file:../doc/index.podlite>

=item1 B<Resources>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>

=end nested
=begin nested :!nested

=item1 B<Resoures>
    =item2 L<Download | file:../download/index.podlite>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=item1 B<Learning>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Wikibook |https://en.wikibooks.org/wiki/Raku_Programming>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>
    =item2 L<Learn Raku in Y minutes|https://learnxinyminutes.com/docs/raku/>
    =item2 L<Golfing |https://github.com/AlexDaniel/raku-golf-cheatsheet>
=end nested
=begin nested :!nested

=item1 B<Explore>
    =item2 L<Raku Blog Aggregator|https://planet.raku.org/>
    =item2 L<Rakudo Weekly|https://rakudoweekly.blog/>
    =item2 L<The Weekly Challenge |https://perlweeklychallenge.org/>
    =item2 L<Raku Advent Calendar|https://raku-advent.blog/>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=end React


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=para
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=end React


Unix

NAME

SYNOPSIS

DESCRIPTION

CAVEATS

AUTHOR

COPYRIGHT AND LICENSE

Universal::Errno v1.0.0

Authors

License

Dependencies

Test Dependencies

Provides

Documentation