---
name: "Tk::Eventloop"
section: "3pm"
platform: "linux"
package: "perl-tk"
version: "804.036-9"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Tk::Eventloop"
---

# Tk::Eventloop(3pm)

ToolKit for Events

## NAME

Tk::Event - ToolKit for Events

## SYNOPSIS

```
 use Tk::Event;
 Tk::Event->fileevent(\*FH, 'readable' => callback);
 Tk::Event->lineavail(\*FH, callback);
 use Tk::Event::Signal qw(INT);
 $SIG{'INT'} = callback;
 use Tk::Event::process;
 Tk::Event->proc($pid, callback);
 QueueEvent(callback [, position])
```

## DESCRIPTION

That is better than nothing but still hard to use. Most scripts want higher level result (a line, a "block" of data etc.)

So it has occured to me that we could use new-ish TIEHANDLE thus:

```
 my $obj = tie SOMEHANDLE,Tk::Event::IO;

 while (<SOMEHANDLE>)
  {
  }
```

Then the READLINE routine registers a callback and looks something like:

```
 sub READLINE
  {
   my $obj = shift;
   Event->io(*$obj,'readable',sub { sysread(*$obj,${*$obj},1,length(${*$obj}) });
   my $pos;
   while (($pos = index(${*$obj},$/) < 0)
    {
     DoOneEvent();
    }
   Event->io(*$obj,'readable',''); # unregister
   $pos += length($/);
   my $result = substr(${*$obj},0,$pos);
   substr(${*$obj},0,$pos) = '';
   return $result;
  }
```

This is using the scalar part of the glob representing the \_inner\_ IO as a buffer in which to accumulate chars.