[perl5.git] / ext / PerlIO-scalar / t / scalar_ungetc.t

#!perl -w
use strict;
use IO::Handle; # ungetc()

use Test::More tests => 20;

require_ok q{PerlIO::scalar};

my $s = 'foo';
Internals::SvREADONLY($s, 1);
eval{
	$s = 'bar';
};
like $@, qr/Modification of a read-only value/, '$s is readonly';

ok open(my $io, '<', \$s), 'open';

getc $io;

my $a = ord 'A';

note "buffer[$s]";
is $io->ungetc($a), $a, 'ungetc';
note "buffer[$s]";

is getc($io), chr($a), 'getc';

is $s, 'foo', '$s remains "foo"';

is getc($io), 'o', 'getc/2';
is getc($io), 'o', 'getc/3';
is getc($io), undef, 'getc/4';

for my $c($a .. ($a+10)){
	is $io->ungetc($c), $c, "ungetc($c)";
}
Commit	Line	Data
d85e265b MS	1	#!perl -w
	2	use strict;
	3	use IO::Handle; # ungetc()
	4
	5	use Test::More tests => 20;
	6
	7	require_ok q{PerlIO::scalar};
	8
	9	my $s = 'foo';
	10	Internals::SvREADONLY($s, 1);
	11	eval{
	12	$s = 'bar';
	13	};
	14	like $@, qr/Modification of a read-only value/, '$s is readonly';
	15
	16	ok open(my $io, '<', \$s), 'open';
	17
	18	getc $io;
	19
	20	my $a = ord 'A';
	21
	22	note "buffer[$s]";
	23	is $io->ungetc($a), $a, 'ungetc';
	24	note "buffer[$s]";
	25
	26	is getc($io), chr($a), 'getc';
	27
	28	is $s, 'foo', '$s remains "foo"';
	29
	30	is getc($io), 'o', 'getc/2';
	31	is getc($io), 'o', 'getc/3';
	32	is getc($io), undef, 'getc/4';
	33
	34	for my $c($a .. ($a+10)){
	35	is $io->ungetc($c), $c, "ungetc($c)";
	36	}