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.\"
.IX Title "IO 3"
.TH IO 3 2023-07-25 "perl v5.38.0" "User Contributed Perl Documentation"
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.SH NAME
Tk::IO \- high level interface to Tk's 'fileevent' mechanism
.SH SYNOPSIS
.IX Header "SYNOPSIS"
.Vb 4
\&  my $fh = Tk::IO\->new(\-linecommand => callback, \-childcommand => callback);
\&  $fh\->exec("command")
\&  $fh\->wait
\&  $fh\->kill
.Ve
.SH WARNING
.IX Header "WARNING"
INTERFACES TO THIS MODULE MAY CHANGE AS PERL'S IO EVOLVES
AND WITH PORT OF TK4.1
.SH DESCRIPTION
.IX Header "DESCRIPTION"
Tk::IO is now layered on perl's IO::Handle class. Interfaces
have changed, and are still evolving.
.PP
In theory C methods which enable non-blocking IO as in earlier Tk\-b*
release(s) are still there. I have not changed them to use perl's
additional Configure information, or tested them much.
.PP
Assumption is that \fBexec\fR is
used to fork a child process and a callback is called each time a
complete line arrives up the implied pipe.
.PP
"line" should probably be defined in terms of perl's input record
separator but is not yet.
.PP
The \-childcommand callback is called when end-of-file occurs.
.PP
\&\f(CW$fh\fR\->\fBwait\fR can be used to wait for child process while processing
other Tk events.
.PP
\&\f(CW$fh\fR\->\fBkill\fR can be used to send signal to child process.
.SH BUGS
.IX Header "BUGS"
Still not finished.
Idea is to use "exec" to emulate "system" in a non-blocking manner.