File Coverage

blib/lib/File/Tail/Lite.pm

Criterion	Covered	Total	%
statement	29	49	59.1
branch	9	22	40.9
condition	7	21	33.3
subroutine	4	4	100.0
pod	2	2	100.0
total	51	98	52.0

package File::Tail::Lite;
use strict;
use warnings;

our $VERSION = '0.01';

sub new {
    my $pkg  = shift;
    my $self = {@_};
    bless $self, $pkg;

    unless ( defined $self->{filename} and -e $self->{filename} ) {
        $self->{error}   = 1;
        $self->{errinfo} = "error input filename";
        return $self;
    }

    unless ( open $self->{fh}, "<", $self->{filename} ) {
        $self->{error}   = 1;
        $self->{errinfo} = "error open file";
        return $self;
    }

    my $seek_position;
    my $seek_whence;    # 0:begin, 1:current, 2:eof
    if ( !defined $self->{seekpos} ) {
        $seek_position = 0;
        $seek_whence   = 2;
    }
    else {
        if (   $self->{seekpos} eq 'begin'
            or $self->{seekpos} eq 'new'
            or $self->{seekpos} eq 'start' )
        {
            $seek_position = 0;
            $seek_whence   = 0;
        }
        elsif ( $self->{seekpos} eq 'end' or $self->{seekpos} eq 'eof' ) {
            $seek_position = 0;
            $seek_whence   = 2;
        }
        elsif ( $self->{seekpos} !~ /^[0-9]+$/ ) {
            $seek_position = $self->{seekpos};
            $seek_whence   = 0;
        }
        else {
            $self->{error}   = 1;
            $self->{errinfo} = "error seekpos";
            return $self;
        }
    }
    unless ( sysseek( $self->{fh}, $seek_position, $seek_whence ) ) {
        $self->{error}   = 1;
        $self->{errinfo} = "error seek file";
        return $self;
    }

    $self->{maxbuf} = 1024
      if !$self->{maxbuf}
      or int( $self->{maxbuf} ) < 1
      or int( $self->{maxbuf} ) > 1024 * 1024;

    return $self;
}

sub readline {
    my $self = shift;
    if ( $self->{error} ) {
        return $self->{errinfo};
    }

    my $line;
    while (1) {
        my $buf;
        my $ret = sysread( $self->{fh}, $buf, 1 );
        if ($ret) {
            $line .= $buf;
            if ( $buf =~ /[\r\n]/ or length($line) >= $self->{maxbuf} ) {
                return ( sysseek( $self->{fh}, 0, 1 ), $line );
            }
        }
        else {
            sleep 1;
        }
    }
}

1;

__END__