/usr/share/perl5/Proc/Guard.pm is in libproc-guard-perl 0.07-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 | package Proc::Guard;
use strict;
use warnings;
use 5.00800;
our $VERSION = '0.07';
use Carp ();
our $EXIT_STATUS;
# functional interface
our @EXPORT = qw/proc_guard/;
use Exporter 'import';
sub proc_guard {
return Proc::Guard->new(do {
if (@_==1 && ref($_[0]) && ref($_[0]) eq 'CODE') {
+{ code => $_[0] }
} else {
+{ command => [@_] }
}
});
}
# OOish interface
use POSIX;
use Errno qw/EINTR ECHILD/;
use Class::Accessor::Lite 0.05 (
rw => ['pid'],
);
sub new {
my $class = shift;
my %args = @_==1 ? %{$_[0]} : @_;
my $self = bless {
_owner_pid => $$,
auto_start => 1,
%args,
}, $class;
if ($self->{command} && !ref($self->{command})) {
$self->{command} = [$self->{command}];
}
unless ($self->{command} || $self->{code}) {
Carp::croak("'command' or 'code' is required.");
}
$self->start()
if $self->{auto_start};
return $self;
}
sub start {
my $self = shift;
my $pid = fork();
die "fork failed: $!" unless defined $pid;
if ($pid == 0) { # child
if ($self->{command}) {
exec @{$self->{command}};
die "cannot exec @{$self->{command}}: $!";
} else {
$self->{code}->();
exit(0); # exit after work
}
}
$self->pid($pid);
}
sub stop {
my ( $self, $sig ) = @_;
return
unless defined $self->pid;
$sig ||= SIGTERM;
kill $sig, $self->pid;
LOOP: {
if ( waitpid( $self->pid, 0 ) > 0 ) {
$EXIT_STATUS = $?;
last LOOP;
}
redo LOOP if $! == EINTR;
# on any other error, we have no reason to think that
# trying again will succeed; on ECHILD, that pid is gone
# or not ours, so give up; anything else is strange
warn "waitpid() error: $!\n" if $! != ECHILD;
# waitpid wasn't successful so $? is undefined
$EXIT_STATUS = undef;
}
$self->pid(undef);
}
sub DESTROY {
my $self = shift;
if (defined $self->pid && $$ == $self->{_owner_pid}) {
local $?; # "END" function and destructors can change the exit status by modifying $?.(perldoc -f exit)
$self->stop()
}
}
1;
__END__
=encoding utf8
=head1 NAME
Proc::Guard - process runner with RAII pattern
=head1 SYNOPSIS
use Test::TCP qw/empty_port wait_port/;
use File::Which qw/which/;
use Proc::Guard;
my $port = empty_port();
my $proc = proc_guard(scalar(which('memcached')), '-p', $port);
wait_port($port);
# your code here
# --------------
# or, use perl code
my $proc = proc_guard(sub {
... # run this code in child process
});
...
=head1 DESCRIPTION
Proc::Guard runs process, and destroys it when the perl script exits.
This is useful for testing code working with server process.
=head1 FUNCTIONS
=over 4
=item proc_guard(@cmdline|\&code)
This is shorthand for:
Proc::Guard->new(
command => \@cmdline,
);
or
Proc::Guard->new(
code => \&code,
);
=back
=head1 METHODS
=over 4
=item my $proc = Proc::Guard->new(%args);
Create and run a process. The process is terminated when the returned object is being DESTROYed.
=over 4
=item command
Proc::Guard->new(command => '/path/to/memcached');
# or
Proc::Guard->new(command => ['/path/to/memcached', '-p', '11211']);
The command line.
=item code
Proc::Guard->new(code => sub { ... });
'code' or 'command' is required.
=item auto_start
Proc::Guard->new(auto_start => 0);
Start child process automatically or not(default: 1).
=back
=item pid
Returns process id (or undef if not running).
=item start
Starts process.
=item stop
Stops process.
=back
=head1 VARIABLES
=over 4
=item $Proc::Guard::EXIT_STATUS
The last exit status code by C<< $proc->stop >>. If C<waitpid>
failed with an error, this will be set to C<undef>.
=back
=head1 AUTHOR
Tokuhiro Matsuno E<lt>tokuhirom AAJKLFJEF GMAIL COME<gt>
=head1 LICENSE
Copyright (C) Tokuhiro Matsuno
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
=cut
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