source: vendor/perl/5.8.8/t/io/layers.t

#!./perl

my $PERLIO;

BEGIN {
    chdir 't' if -d 't';
    @INC = '../lib';
    require './test.pl';
    unless (find PerlIO::Layer 'perlio') {
        print "1..0 # Skip: not perlio\n";
        exit 0;
    }
    eval 'use Encode';
    if ($@ =~ /dynamic loading not available/) {
        print "1..0 # miniperl cannot load Encode\n";
        exit 0;
    }
    # Makes testing easier.
    $ENV{PERLIO} = 'stdio' if exists $ENV{PERLIO} && $ENV{PERLIO} eq '';
    if (exists $ENV{PERLIO} && $ENV{PERLIO} !~ /^(stdio|perlio|mmap)$/) {
        # We are not prepared for anything else.
        print "1..0 # PERLIO='$ENV{PERLIO}' unknown\n";
        exit 0;
    }
    $PERLIO = exists $ENV{PERLIO} ? $ENV{PERLIO} : "(undef)";
}

use Config;

my $DOSISH    = $^O =~ /^(?:MSWin32|os2|dos|NetWare|mint)$/ ? 1 : 0;
   $DOSISH    = 1 if !$DOSISH and $^O =~ /^uwin/;
my $NONSTDIO  = exists $ENV{PERLIO} && $ENV{PERLIO} ne 'stdio'     ? 1 : 0;
my $FASTSTDIO = $Config{d_faststdio} && $Config{usefaststdio}      ? 1 : 0;
my $UNICODE_STDIN;
if (${^UNICODE} & 1) {
    if (${^UNICODE} & 64) {
        # Conditional on the locale
        $UNICODE_STDIN = ${^UTF8LOCALE};
    } else {
        # Unconditional
        $UNICODE_STDIN = 1;
    }
} else {
    $UNICODE_STDIN = 0;
}
my $NTEST = 44 - (($DOSISH || !$FASTSTDIO) ? 7 : 0) - ($DOSISH ? 5 : 0)
    + $UNICODE_STDIN;

sub PerlIO::F_UTF8 () { 0x00008000 } # from perliol.h

plan tests => $NTEST;

print <<__EOH__;
# PERLIO        = $PERLIO
# DOSISH        = $DOSISH
# NONSTDIO      = $NONSTDIO
# FASTSTDIO     = $FASTSTDIO
# UNICODE       = ${^UNICODE}
# UTF8LOCALE    = ${^UTF8LOCALE}
# UNICODE_STDIN = $UNICODE_STDIN
__EOH__

SKIP: {
    # FIXME - more of these could be tested without Encode or full perl
    skip("This perl does not have Encode", $NTEST)
        unless " $Config{extensions} " =~ / Encode /;
    skip("miniperl does not have Encode", $NTEST) if $ENV{PERL_CORE_MINITEST};

    sub check {
        my ($result, $expected, $id) = @_;
        # An interesting dance follows where we try to make the following
        # IO layer stack setups to compare equal:
        #
        # PERLIO     UNIX-like                   DOS-like
        #
        # unset / "" unix perlio / stdio [1]     unix crlf
        # stdio      unix perlio / stdio [1]     stdio
        # perlio     unix perlio                 unix perlio
        # mmap       unix mmap                   unix mmap
        #
        # [1] "stdio" if Configure found out how to do "fast stdio" (depends
        # on the stdio implementation) and in Perl 5.8, otherwise "unix perlio"
        #
        if ($NONSTDIO) {
            # Get rid of "unix".
            shift @$result if $result->[0] eq "unix";
            # Change expectations.
            if ($FASTSTDIO) {
                $expected->[0] = $ENV{PERLIO};
            } else {
                $expected->[0] = $ENV{PERLIO} if $expected->[0] eq "stdio";
            }
        } elsif (!$FASTSTDIO && !$DOSISH) {
            splice(@$result, 0, 2, "stdio")
                if @$result >= 2 &&
                   $result->[0] eq "unix" &&
                   $result->[1] eq "perlio";
        } elsif ($DOSISH) {
            splice(@$result, 0, 2, "stdio")
                if @$result >= 2 &&
                   $result->[0] eq "unix" &&
                   $result->[1] eq "crlf";
        }
        if ($DOSISH && grep { $_ eq 'crlf' } @$expected) {
            # 5 tests potentially skipped because
            # DOSISH systems already have a CRLF layer
            # which will make new ones not stick.
            @$expected = grep { $_ ne 'crlf' } @$expected;
        }
        my $n = scalar @$expected;
        is(scalar @$result, $n, "$id - layers == $n");
        for (my $i = 0; $i < $n; $i++) {
            my $j = $expected->[$i];
            if (ref $j eq 'CODE') {
                ok($j->($result->[$i]), "$id - $i is ok");
            } else {
                is($result->[$i], $j,
                   sprintf("$id - $i is %s",
                           defined $j ? $j : "undef"));
            }
        }
    }

    check([ PerlIO::get_layers(STDIN) ],
          $UNICODE_STDIN ? [ "stdio", "utf8" ] : [ "stdio" ],
          "STDIN");

    open(F, ">:crlf", "afile");

    check([ PerlIO::get_layers(F) ],
          [ qw(stdio crlf) ],
          "open :crlf");

    binmode(F, ":encoding(sjis)"); # "sjis" will be canonized to "shiftjis"

    check([ PerlIO::get_layers(F) ],
          [ qw[stdio crlf encoding(shiftjis) utf8] ],
          ":encoding(sjis)");
    
    binmode(F, ":pop");

    check([ PerlIO::get_layers(F) ],
          [ qw(stdio crlf) ],
          ":pop");

    binmode(F, ":raw");

    check([ PerlIO::get_layers(F) ],
          [ "stdio" ],
          ":raw");

    binmode(F, ":utf8");

    check([ PerlIO::get_layers(F) ],
          [ qw(stdio utf8) ],
          ":utf8");

    binmode(F, ":bytes");

    check([ PerlIO::get_layers(F) ],
          [ "stdio" ],
          ":bytes");

    binmode(F, ":encoding(utf8)");

    check([ PerlIO::get_layers(F) ],
            [ qw[stdio encoding(utf8) utf8] ],
            ":encoding(utf8)");

    binmode(F, ":raw :crlf");

    check([ PerlIO::get_layers(F) ],
          [ qw(stdio crlf) ],
          ":raw:crlf");

    binmode(F, ":raw :encoding(latin1)"); # "latin1" will be canonized

    # 7 tests potentially skipped.
    unless ($DOSISH || !$FASTSTDIO) {
        my @results = PerlIO::get_layers(F, details => 1);

        # Get rid of the args and the flags.
        splice(@results, 1, 2) if $NONSTDIO;

        check([ @results ],
              [ "stdio",    undef,        sub { $_[0] > 0 },
                "encoding", "iso-8859-1", sub { $_[0] & PerlIO::F_UTF8() } ],
              ":raw:encoding(latin1)");
    }

    binmode(F);

    check([ PerlIO::get_layers(F) ],
          [ "stdio" ],
          "binmode");

    close F;

    {
        use open(IN => ":crlf", OUT => ":encoding(cp1252)");

        open F, "<afile";
        open G, ">afile";

        check([ PerlIO::get_layers(F, input  => 1) ],
              [ qw(stdio crlf) ],
              "use open IN");
        
        check([ PerlIO::get_layers(G, output => 1) ],
              [ qw[stdio encoding(cp1252) utf8] ],
              "use open OUT");

        close F;
        close G;
    }

    # Check that PL_sigwarn's reference count is correct, and that 
    # &PerlIO::Layer::NoWarnings isn't prematurely freed.
    fresh_perl_like (<<'EOT', qr/^CODE/);
open(UTF, "<:raw:encoding(utf8)", "afile") or die $!;
print ref *PerlIO::Layer::NoWarnings{CODE};
EOT

    1 while unlink "afile";
}