Tee(3) User Contributed Perl Documentation Tee(3)NAMEIO::Tee - Multiplex output to multiple output handles
SYNOPSIS
use IO::Tee;
$tee = IO::Tee->new($handle1, $handle2);
print $tee "foo", "bar";
my $input = <$tee>;
DESCRIPTION
"IO::Tee" objects can be used to multiplex input and output in two dif‐
ferent ways. The first way is to multiplex output to zero or more out‐
put handles. The "IO::Tee" constructor, given a list of output han‐
dles, returns a tied handle that can be written to. When written to
(using print or printf), the "IO::Tee" object multiplexes the output to
the list of handles originally passed to the constructor. As a short‐
cut, you can also directly pass a string or an array reference to the
constructor, in which case "IO::File::new" is called for you with the
specified argument or arguments.
The second way is to multiplex input from one input handle to zero or
more output handles as it is being read. The "IO::Tee" constructor,
given an input handle followed by a list of output handles, returns a
tied handle that can be read from as well as written to. When written
to, the "IO::Tee" object multiplexes the output to all handles passed
to the constructor, as described in the previous paragraph. When read
from, the "IO::Tee" object reads from the input handle given as the
first argument to the "IO::Tee" constructor, then writes any data read
to the output handles given as the remaining arguments to the construc‐
tor.
The "IO::Tee" class supports certain "IO::Handle" and "IO::File" meth‐
ods related to input and output. In particular, the following methods
will iterate themselves over all handles associated with the "IO::Tee"
object, and return TRUE indicating success if and only if all associ‐
ated handles returned TRUE indicating success:
close
truncate
write
syswrite
format_write
formline
fcntl
ioctl
flush
clearerr
seek
The following methods perform input multiplexing as described above:
read
sysread
readline
getc
gets
eof
getline
getlines
The following methods can be used to set (but not retrieve) the current
values of output-related state variables on all associated handles:
autoflush
output_field_separator
output_record_separator
format_page_number
format_lines_per_page
format_lines_left
format_name
format_top_name
format_line_break_characters
format_formfeed
The following methods are directly passed on to the input handle given
as the first argument to the "IO::Tee" constructor:
input_record_separator
input_line_number
Note that the return value of input multiplexing methods (such as
"print") is always the return value of the input action, not the return
value of subsequent output actions. In particular, no error is indi‐
cated by the return value if the input action itself succeeds but sub‐
sequent output multiplexing fails.
EXAMPLE
use IO::Tee;
use IO::File;
my $tee = new IO::Tee(\*STDOUT,
new IO::File(">tt1.out"), ">tt2.out");
print join(' ', $tee->handles), "\n";
for (1..10) { print $tee $_, "\n" }
for (1..10) { $tee->print($_, "\n") }
$tee->flush;
$tee = new IO::Tee('</etc/passwd', \*STDOUT);
my @lines = <$tee>;
print scalar(@lines);
AUTHOR
Chung-chieh Shan, ken@digitas.harvard.edu
COPYRIGHT
Copyright (c) 1998-2001 Chung-chieh Shan. All rights reserved. This
program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
SEE ALSO
the perlfunc manpage, the IO::Handle manpage, the IO::File manpage.
3rd Berkeley Distribution perl v5.6.1 Tee(3)
