$ diff /usr/perl5/5.22/lib/IPC/Cmd.pm /usr/perl5/site_perl/5.26/IPC/Cmd.pm
8a9
>     use constant IS_HPUX        => $^O eq 'hpux'                      ? 1 : 0;
21c22
<     $VERSION        = '0.92';
---
>     $VERSION        = '1.04';
62a64,65
> local $Module::Load::Conditional::FORCE_SAFE_INC = 1;
>
243c246
<             File::Spec->curdir
---
>             ( IS_WIN32 ? File::Spec->curdir : () )
401a405,412
> sub uninstall_signals {
>               return unless defined($IPC::Cmd::{'__old_signals'});
>
>               foreach my $sig_name (keys %{$IPC::Cmd::{'__old_signals'}}) {
>                               $SIG{$sig_name} = $IPC::Cmd::{'__old_signals'}->{$sig_name};
>               }
> }
>
413a425,428
>   $IPC::Cmd::{'__old_signals'} = {}
>               unless defined($IPC::Cmd::{'__old_signals'});
>       $IPC::Cmd::{'__old_signals'}->{$s} = $SIG{$s};
>
479c494
<
---
>
494c509
<
---
>
519a535
>     Time::HiRes::usleep(1) if IS_HPUX;
520a537,540
>     # will consider myself orphan if my ppid changes
>     # from this one:
>     my $original_ppid = $opts->{'original_ppid'};
>
571c591,592
<     foreach my $s (keys %SIG) {
---
>     SIGNAL: foreach my $s (keys %SIG) {
>         next SIGNAL if $s eq '__WARN__' or $s eq '__DIE__'; # Skip and don't clobber __DIE__ & __WARN__
589c610
<         if (getppid() eq "1") {
---
>         if (getppid() != $original_ppid) {
729a751
> =item C<wait_loop_callback>
730a753,774
> Coderef of a subroutine to call inside of the main waiting loop
> (while C<run_forked> waits for the external to finish or fail).
> It is useful to stop running external process before it ends
> by itself, e.g.
>
>   my $r = run_forked("some external command", {
>         'wait_loop_callback' => sub {
>           if (condition) {
>               kill(1, $$);
>           }
>         },
>         'terminate_on_signal' => 'HUP',
>         });
>
> Combined with C<stdout_handler> and C<stderr_handler> allows terminating
> external command based on its output. Could also be used as a timer
> without engaging with L<alarm> (signals).
>
> Remember that this code could be called every millisecond (depending
> on the output which external command generates), so try to make it
> as lightweight as possible.
>
835a880
>     my $ppid = $$;
847,848c892
<       $flags = 0;
<       fcntl($child_stdout_socket, POSIX::F_GETFL, $flags) || Carp::confess "can't fnctl F_GETFL: $!";
---
>       $flags = fcntl($child_stdout_socket, POSIX::F_GETFL, 0) || Carp::confess "can't fnctl F_GETFL: $!";
852,853c896
<       $flags = 0;
<       fcntl($child_stderr_socket, POSIX::F_GETFL, $flags) || Carp::confess "can't fnctl F_GETFL: $!";
---
>       $flags = fcntl($child_stderr_socket, POSIX::F_GETFL, 0) || Carp::confess "can't fnctl F_GETFL: $!";
857,858c900
<       $flags = 0;
<       fcntl($child_info_socket, POSIX::F_GETFL, $flags) || Carp::confess "can't fnctl F_GETFL: $!";
---
>       $flags = fcntl($child_info_socket, POSIX::F_GETFL, 0) || Carp::confess "can't fnctl F_GETFL: $!";
1065a1108,1111
>         if ($opts->{'wait_loop_callback'} && ref($opts->{'wait_loop_callback'}) eq 'CODE') {
>           $opts->{'wait_loop_callback'}->();
>         }
>
1147a1194,1195
>       uninstall_signals();
>
1159c1207
<       POSIX::setsid() || Carp::confess("Error running setsid: " . $!);
---
>       POSIX::setsid() == -1 and Carp::confess("Error running setsid: " . $!);
1178a1227
>           'original_ppid' => $ppid,
1935a1985,1986
> __END__
>
1950,1951d2000
< __END__
<