JezK
Edit File: Open3.pm
package IPC::Open3; use strict; no strict 'refs'; # because users pass me bareword filehandles use Exporter 'import'; use Carp; use Symbol qw(gensym qualify); our $VERSION = '1.22'; our @EXPORT = qw(open3); # &open3: Marc Horowitz <marc@mit.edu> # derived mostly from &open2 by tom christiansen, <tchrist@convex.com> # fixed for 5.001 by Ulrich Kunitz <kunitz@mai-koeln.com> # ported to Win32 by Ron Schmidt, Merrill Lynch almost ended my career # fixed for autovivving FHs, tchrist again # allow fd numbers to be used, by Frank Tobin # allow '-' as command (c.f. open "-|"), by Adam Spiers <perl@adamspiers.org> # # usage: $pid = open3('wtr', 'rdr', 'err' 'some cmd and args', 'optarg', ...); # # spawn the given $cmd and connect rdr for # reading, wtr for writing, and err for errors. # if err is '', or the same as rdr, then stdout and # stderr of the child are on the same fh. returns pid # of child (or dies on failure). # if wtr begins with '<&', then wtr will be closed in the parent, and # the child will read from it directly. if rdr or err begins with # '>&', then the child will send output directly to that fd. In both # cases, there will be a dup() instead of a pipe() made. # WARNING: this is dangerous, as you may block forever # unless you are very careful. # # $wtr is left unbuffered. # # abort program if # rdr or wtr are null # a system call fails our $Me = 'open3 (bug)'; # you should never see this, it's always localized # Fatal.pm needs to be fixed WRT prototypes. sub xpipe { pipe $_[0], $_[1] or croak "$Me: pipe($_[0], $_[1]) failed: $!"; } # I tried using a * prototype character for the filehandle but it still # disallows a bareword while compiling under strict subs. sub xopen { open $_[0], $_[1], @_[2..$#_] and return; local $" = ', '; carp "$Me: open(@_) failed: $!"; } sub xclose { $_[0] =~ /\A=?(\d+)\z/ ? do { my $fh; open($fh, $_[1] . '&=' . $1) and close($fh); } : close $_[0] or croak "$Me: close($_[0]) failed: $!"; } sub xfileno { return $1 if $_[0] =~ /\A=?(\d+)\z/; # deal with fh just being an fd return fileno $_[0]; } use constant FORCE_DEBUG_SPAWN => 0; use constant DO_SPAWN => $^O eq 'os2' || $^O eq 'MSWin32' || FORCE_DEBUG_SPAWN; sub _open3 { local $Me = shift; # simulate autovivification of filehandles because # it's too ugly to use @_ throughout to make perl do it for us # tchrist 5-Mar-00 # Historically, open3(undef...) has silently worked, so keep # it working. splice @_, 0, 1, undef if \$_[0] == \undef; splice @_, 1, 1, undef if \$_[1] == \undef; unless (eval { $_[0] = gensym unless defined $_[0] && length $_[0]; $_[1] = gensym unless defined $_[1] && length $_[1]; 1; }) { # must strip crud for croak to add back, or looks ugly $@ =~ s/(?<=value attempted) at .*//s; croak "$Me: $@"; } my @handles = ({ mode => '<', handle => \*STDIN }, { mode => '>', handle => \*STDOUT }, { mode => '>', handle => \*STDERR }, ); foreach (@handles) { $_->{parent} = shift; $_->{open_as} = gensym; } if (@_ > 1 and $_[0] eq '-') { croak "Arguments don't make sense when the command is '-'" } $handles[2]{parent} ||= $handles[1]{parent}; $handles[2]{dup_of_out} = $handles[1]{parent} eq $handles[2]{parent}; my $package; foreach (@handles) { $_->{dup} = ($_->{parent} =~ s/^[<>]&//); if ($_->{parent} !~ /\A=?(\d+)\z/) { # force unqualified filehandles into caller's package $package //= caller 1; $_->{parent} = qualify $_->{parent}, $package; } next if $_->{dup} or $_->{dup_of_out}; if ($_->{mode} eq '<') { xpipe $_->{open_as}, $_->{parent}; } else { xpipe $_->{parent}, $_->{open_as}; } } my $kidpid; if (!DO_SPAWN) { # Used to communicate exec failures. xpipe my $stat_r, my $stat_w; $kidpid = fork; croak "$Me: fork failed: $!" unless defined $kidpid; if ($kidpid == 0) { # Kid eval { # A tie in the parent should not be allowed to cause problems. untie *STDIN; untie *STDOUT; untie *STDERR; close $stat_r; require Fcntl; my $flags = fcntl $stat_w, &Fcntl::F_GETFD, 0; croak "$Me: fcntl failed: $!" unless $flags; fcntl $stat_w, &Fcntl::F_SETFD, $flags|&Fcntl::FD_CLOEXEC or croak "$Me: fcntl failed: $!"; # If she wants to dup the kid's stderr onto her stdout I need to # save a copy of her stdout before I put something else there. if (!$handles[2]{dup_of_out} && $handles[2]{dup} && xfileno($handles[2]{parent}) == fileno \*STDOUT) { my $tmp = gensym; xopen($tmp, '>&', $handles[2]{parent}); $handles[2]{parent} = $tmp; } foreach (@handles) { if ($_->{dup_of_out}) { xopen \*STDERR, ">&STDOUT" if defined fileno STDERR && fileno STDERR != fileno STDOUT; } elsif ($_->{dup}) { xopen $_->{handle}, $_->{mode} . '&', $_->{parent} if fileno $_->{handle} != xfileno($_->{parent}); } else { xclose $_->{parent}, $_->{mode}; xopen $_->{handle}, $_->{mode} . '&=', fileno $_->{open_as}; } } return 1 if ($_[0] eq '-'); exec @_ or do { local($")=(" "); croak "$Me: exec of @_ failed: $!"; }; } and do { close $stat_w; return 0; }; my $bang = 0+$!; my $err = $@; utf8::encode $err if $] >= 5.008; print $stat_w pack('IIa*', $bang, length($err), $err); close $stat_w; eval { require POSIX; POSIX::_exit(255); }; exit 255; } else { # Parent close $stat_w; my $to_read = length(pack('I', 0)) * 2; my $bytes_read = read($stat_r, my $buf = '', $to_read); if ($bytes_read) { (my $bang, $to_read) = unpack('II', $buf); read($stat_r, my $err = '', $to_read); waitpid $kidpid, 0; # Reap child which should have exited if ($err) { utf8::decode $err if $] >= 5.008; } else { $err = "$Me: " . ($! = $bang); } $! = $bang; die($err); } } } else { # DO_SPAWN # All the bookkeeping of coincidence between handles is # handled in spawn_with_handles. my @close; foreach (@handles) { if ($_->{dup_of_out}) { $_->{open_as} = $handles[1]{open_as}; } elsif ($_->{dup}) { $_->{open_as} = $_->{parent} =~ /\A[0-9]+\z/ ? $_->{parent} : \*{$_->{parent}}; push @close, $_->{open_as}; } else { push @close, \*{$_->{parent}}, $_->{open_as}; } } require IO::Pipe; $kidpid = eval { spawn_with_handles(\@handles, \@close, @_); }; die "$Me: $@" if $@; } foreach (@handles) { next if $_->{dup} or $_->{dup_of_out}; xclose $_->{open_as}, $_->{mode}; } # If the write handle is a dup give it away entirely, close my copy # of it. xclose $handles[0]{parent}, $handles[0]{mode} if $handles[0]{dup}; select((select($handles[0]{parent}), $| = 1)[0]); # unbuffer pipe $kidpid; } sub open3 { if (@_ < 4) { local $" = ', '; croak "open3(@_): not enough arguments"; } return _open3 'open3', @_ } sub spawn_with_handles { my $fds = shift; # Fields: handle, mode, open_as my $close_in_child = shift; my ($fd, %saved, @errs); foreach $fd (@$fds) { $fd->{tmp_copy} = IO::Handle->new_from_fd($fd->{handle}, $fd->{mode}); $saved{fileno $fd->{handle}} = $fd->{tmp_copy} if $fd->{tmp_copy}; } foreach $fd (@$fds) { bless $fd->{handle}, 'IO::Handle' unless eval { $fd->{handle}->isa('IO::Handle') } ; # If some of handles to redirect-to coincide with handles to # redirect, we need to use saved variants: my $open_as = $fd->{open_as}; my $fileno = fileno($open_as); $fd->{handle}->fdopen(defined($fileno) ? $saved{$fileno} || $open_as : $open_as, $fd->{mode}); } unless ($^O eq 'MSWin32') { require Fcntl; # Stderr may be redirected below, so we save the err text: foreach $fd (@$close_in_child) { next unless fileno $fd; fcntl($fd, Fcntl::F_SETFD(), 1) or push @errs, "fcntl $fd: $!" unless $saved{fileno $fd}; # Do not close what we redirect! } } my $pid; unless (@errs) { if (FORCE_DEBUG_SPAWN) { pipe my $r, my $w or die "Pipe failed: $!"; $pid = fork; die "Fork failed: $!" unless defined $pid; if (!$pid) { { no warnings; exec @_ } print $w 0 + $!; close $w; require POSIX; POSIX::_exit(255); } close $w; my $bad = <$r>; if (defined $bad) { $! = $bad; undef $pid; } } else { $pid = eval { system 1, @_ }; # 1 == P_NOWAIT } if($@) { push @errs, "IO::Pipe: Can't spawn-NOWAIT: $@"; } elsif(!$pid || $pid < 0) { push @errs, "IO::Pipe: Can't spawn-NOWAIT: $!"; } } # Do this in reverse, so that STDERR is restored first: foreach $fd (reverse @$fds) { $fd->{handle}->fdopen($fd->{tmp_copy}, $fd->{mode}); } foreach (values %saved) { $_->close or croak "Can't close: $!"; } croak join "\n", @errs if @errs; return $pid; } 1; # so require is happy