NAME
IPC::Open3::Callback::NullLogger - An extension to IPC::Open3 that will feed out and err to callbacks instead of requiring the caller to handle them.
VERSION
version 1.04
SYNOPSIS
use IPC::Open3::Callback;
my $runner = IPC::Open3::Callback->new( {
out_callback => sub {
my $data = shift;
my $pid = shift;
print( "$pid STDOUT: $data\n" );
},
err_callback => sub {
my $data = shift;
my $pid = shift;
print( "$pid STDERR: $data\n" );
} } );
my $exit_code = $runner->run_command( 'echo Hello World' );
use IPC::Open3::Callback qw(safe_open3);
my ($pid, $in, $out, $err) = safe_open3( "echo", "Hello", "world" );
$buffer = '';
my $select = IO::Select->new();
$select->add( $out );
while ( my @ready = $select->can_read( 5 ) ) {
foreach my $fh ( @ready ) {
my $line;
my $bytes_read = sysread( $fh, $line, 1024 );
if ( ! defined( $bytes_read ) && !$!{ECONNRESET} ) {
die( "error in running ('echo $echo'): $!" );
}
elsif ( ! defined( $bytes_read) || $bytes_read == 0 ) {
$select->remove( $fh );
next;
}
else {
if ( $fh == $out ) {
$buffer .= $line;
}
else {
die( "impossible... somehow got a filehandle i dont know about!" );
}
}
}
}
waitpid( $pid, 0 );
my $exit_code = $? >> 8;
print( "$pid exited with $exit_code: $buffer\n" ); # 123 exited with 0: Hello WorldDESCRIPTION
This module feeds output and error stream from a command to supplied callbacks. Thus, this class removes the necessity of dealing with IO::Select by hand and also provides a workaround for Windows systems.
FUNCTIONS
safe_open3( $command, $arg1, ..., $argN )
Passes the command and arguments on to open3 and returns a list containing:
- pid
-
The process id of the forked process
- stdin
-
An IO::Handle to STDIN for the process
- stdout
-
An IO::Handle to STDOUT for the process
- stderr
-
An IO::Handle to STDERR for the process
As with open3, it is the callers responsibility to waitpid to ensure forked processes do not become zombies.
This method works for both *nix and Windows sytems. On a windows system, it will use sockets per http://www.perlmonks.org/index.pl?node_id=811150.
CONSTRUCTORS
new( \%options )
The constructor creates a new Callback object and optionally sets global callbacks for STDOUT and STDERR streams from commands that will get run by this object (can be overridden per call to run_command).
- out_callback
-
A subroutine to call for each chunk of text written to
STDOUT. This subroutine will be called with 2 arguments:- data
-
A chunk of text written to the stream
- pid
-
The pid of the forked process
- err_callback
-
A subroutine to call for each chunk of text written to
STDERR. This subroutine will be called with the same 2 arguments asout_callback - buffer_output
-
A boolean value, if true, will buffer output and send to callback one line at a time (waits for '\n'). Otherwise, sends text in the same chunks returned by sysread.
- select_timeout
-
The timeout, in seconds, provided to
IO::Select, by default 0 meaning no timeout which will cause the loop to block until output is ready on eitherSTDOUTorSTDERR.
METHODS
run_command( $command, $arg1, ..., $argN, \%options )
Will run the specified command with the supplied arguments by passing them on to safe_open3. Arguments can be embedded in the command string and are thus optional.
If the last argument to this method is a hashref (ref(@_[-1]) eq 'HASH'), then it is treated as an options hash. The supported allowed options are the same as the constructor and will be used in preference to the values set in the constructor for this call.
Returns the exit code from the command.
AUTHORS
Lucas Theisen <lucastheisen@pastdev.com>
Alceu Rodrigues de Freitas Junior <arfreitas@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2013 by Lucas Theisen.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
SEE ALSO
Please see those modules/websites for more information related to this module.