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

#!./perl

BEGIN {
    chdir 't' if -d 't';
    @INC = '../lib';
}

require "./test.pl";

plan(tests => 22);

use File::Spec;

my $devnull = File::Spec->devnull;

open(TRY, '>Io_argv1.tmp') || (die "Can't open temp file: $!");
print TRY "a line\n";
close TRY or die "Could not close: $!";

$x = runperl(
    prog        => 'while (<>) { print $., $_; }',
    args        => [ 'Io_argv1.tmp', 'Io_argv1.tmp' ],
);
is($x, "1a line\n2a line\n", '<> from two files');

{
    $x = runperl(
        prog    => 'while (<>) { print $_; }',
        stdin   => "foo\n",
        args    => [ 'Io_argv1.tmp', '-' ],
    );
    is($x, "a line\nfoo\n", '   from a file and STDIN');

    $x = runperl(
        prog    => 'while (<>) { print $_; }',
        stdin   => "foo\n",
    );
    is($x, "foo\n", '   from just STDIN');
}

@ARGV = ('Io_argv1.tmp', 'Io_argv1.tmp', $devnull, 'Io_argv1.tmp');
while (<>) {
    $y .= $. . $_;
    if (eof()) {
        is($., 3, '$. counts <>');
    }
}

is($y, "1a line\n2a line\n3a line\n", '<> from @ARGV');


open(TRY, '>Io_argv1.tmp') or die "Can't open temp file: $!";
close TRY or die "Could not close: $!";
open(TRY, '>Io_argv2.tmp') or die "Can't open temp file: $!";
close TRY or die "Could not close: $!";
@ARGV = ('Io_argv1.tmp', 'Io_argv2.tmp');
$^I = '_bak';   # not .bak which confuses VMS
$/ = undef;
my $i = 6;
while (<>) {
    s/^/ok $i\n/;
    ++$i;
    print;
    next_test();
}
open(TRY, '<Io_argv1.tmp') or die "Can't open temp file: $!";
print while <TRY>;
open(TRY, '<Io_argv2.tmp') or die "Can't open temp file: $!";
print while <TRY>;
close TRY or die "Could not close: $!";
undef $^I;

ok( eof TRY );

{
    no warnings 'once';
    ok( eof NEVEROPENED,    'eof() true on unopened filehandle' );
}

open STDIN, 'Io_argv1.tmp' or die $!;
@ARGV = ();
ok( !eof(),     'STDIN has something' );

is( <>, "ok 6\n" );

open STDIN, $devnull or die $!;
@ARGV = ();
ok( eof(),      'eof() true with empty @ARGV' );

@ARGV = ('Io_argv1.tmp');
ok( !eof() );

@ARGV = ($devnull, $devnull);
ok( !eof() );

close ARGV or die $!;
ok( eof(),      'eof() true after closing ARGV' );

{
    local $/;
    open F, 'Io_argv1.tmp' or die "Could not open Io_argv1.tmp: $!";
    <F>;        # set $. = 1
    is( <F>, undef );

    open F, $devnull or die;
    ok( defined(<F>) );

    is( <F>, undef );
    is( <F>, undef );

    open F, $devnull or die;    # restart cycle again
    ok( defined(<F>) );
    is( <F>, undef );
    close F or die "Could not close: $!";
}

# This used to dump core
fresh_perl_is( <<'**PROG**', "foobar", {}, "ARGV aliasing and eof()" ); 
open OUT, ">Io_argv3.tmp" or die "Can't open temp file: $!";
print OUT "foo";
close OUT;
open IN, "Io_argv3.tmp" or die "Can't open temp file: $!";
*ARGV = *IN;
while (<>) {
    print;
    print "bar" if eof();
}
close IN;
unlink "Io_argv3.tmp";
**PROG**

END {
    1 while unlink 'Io_argv1.tmp', 'Io_argv1.tmp_bak',
        'Io_argv2.tmp', 'Io_argv2.tmp_bak', 'Io_argv3.tmp';
}