X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=lib%2FPublicInbox%2FLEI.pm;h=6c2515dc0eb74cf37530445e27acb44134d44702;hb=7349713101700e488231ad9ffece8ee42de0928c;hp=fd412324be3b9d3eefbc73f983a0e11938fcd79f;hpb=f2c7b911a1c4a7520091ba7224773c30e409c337;p=public-inbox.git

diff --git a/lib/PublicInbox/LEI.pm b/lib/PublicInbox/LEI.pm
index fd412324..6c2515dc 100644
--- a/lib/PublicInbox/LEI.pm
+++ b/lib/PublicInbox/LEI.pm
@@ -1,4 +1,4 @@
-# Copyright (C) 2020 all contributors <meta@public-inbox.org>
+# Copyright (C) 2020-2021 all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 
 # Backend for `lei' (local email interface).  Unlike the C10K-oriented
@@ -8,23 +8,28 @@
 package PublicInbox::LEI;
 use strict;
 use v5.10.1;
-use parent qw(PublicInbox::DS);
+use parent qw(PublicInbox::DS PublicInbox::LeiExternal
+	PublicInbox::LeiQuery);
 use Getopt::Long ();
-use Socket qw(AF_UNIX SOCK_STREAM pack_sockaddr_un);
-use Errno qw(EAGAIN ECONNREFUSED ENOENT);
-use POSIX ();
+use Socket qw(AF_UNIX SOCK_SEQPACKET MSG_EOR pack_sockaddr_un);
+use Errno qw(EPIPE EAGAIN EINTR ECONNREFUSED ENOENT ECONNRESET);
+use Cwd qw(getcwd);
+use POSIX qw(strftime);
 use IO::Handle ();
-use Sys::Syslog qw(syslog openlog);
+use Fcntl qw(SEEK_SET);
 use PublicInbox::Config;
-use PublicInbox::Syscall qw($SFD_NONBLOCK EPOLLIN EPOLLONESHOT);
+use PublicInbox::Syscall qw(SFD_NONBLOCK EPOLLIN EPOLLET);
 use PublicInbox::Sigfd;
-use PublicInbox::DS qw(now);
-use PublicInbox::Spawn qw(spawn);
+use PublicInbox::DS qw(now dwaitpid);
+use PublicInbox::Spawn qw(spawn popen_rd);
 use PublicInbox::OnDestroy;
 use Text::Wrap qw(wrap);
+use Time::HiRes qw(stat); # ctime comparisons for config cache
 use File::Path qw(mkpath);
 use File::Spec;
 our $quit = \&CORE::exit;
+our ($current_lei, $errors_log, $listener);
+my ($recv_cmd, $send_cmd);
 my $GLP = Getopt::Long::Parser->new;
 $GLP->configure(qw(gnu_getopt no_ignore_case auto_abbrev));
 my $GLP_PASS = Getopt::Long::Parser->new;
@@ -36,40 +41,85 @@ our %PATH2CFG; # persistent for socket daemon
 # (may) pass options through to another command:
 sub pass_through { $GLP_PASS }
 
+my $OPT;
+sub opt_dash ($$) {
+	my ($spec, $re_str) = @_; # 'limit|n=i', '([0-9]+)'
+	my ($key) = ($spec =~ m/\A([a-z]+)/g);
+	my $cb = sub { # Getopt::Long "<>" catch-all handler
+		my ($arg) = @_;
+		if ($arg =~ /\A-($re_str)\z/) {
+			$OPT->{$key} = $1;
+		} elsif ($arg eq '--') { # "--" arg separator, ignore first
+			push @{$OPT->{-argv}}, $arg if $OPT->{'--'}++;
+		# lone (single) dash is handled elsewhere
+		} elsif (substr($arg, 0, 1) eq '-') {
+			if ($OPT->{'--'}) {
+				push @{$OPT->{-argv}}, $arg;
+			} else {
+				die "bad argument: $arg\n";
+			}
+		} else {
+			push @{$OPT->{-argv}}, $arg;
+		}
+	};
+	($spec, '<>' => $cb, $GLP_PASS) # for Getopt::Long
+}
+
+sub rel2abs ($$) {
+	my ($self, $p) = @_;
+	return $p if index($p, '/') == 0; # already absolute
+	my $pwd = $self->{env}->{PWD};
+	if (defined $pwd) {
+		my $cwd = $self->{3} // getcwd() // die "getcwd(PWD=$pwd): $!";
+		if (my @st_pwd = stat($pwd)) {
+			my @st_cwd = stat($cwd) or die "stat($cwd): $!";
+			"@st_pwd[1,0]" eq "@st_cwd[1,0]" or
+				$self->{env}->{PWD} = $pwd = $cwd;
+		} else { # PWD was invalid
+			delete $self->{env}->{PWD};
+			undef $pwd;
+		}
+	}
+	$pwd //= $self->{env}->{PWD} = getcwd() // die "getcwd(PWD=$pwd): $!";
+	File::Spec->rel2abs($p, $pwd);
+}
+
 sub _store_path ($) {
-	my ($env) = @_;
-	File::Spec->rel2abs(($env->{XDG_DATA_HOME} //
-		($env->{HOME} // '/nonexistent').'/.local/share')
-		.'/lei/store', $env->{PWD});
+	my ($self) = @_;
+	rel2abs($self, ($self->{env}->{XDG_DATA_HOME} //
+		($self->{env}->{HOME} // '/nonexistent').'/.local/share')
+		.'/lei/store');
 }
 
 sub _config_path ($) {
-	my ($env) = @_;
-	File::Spec->rel2abs(($env->{XDG_CONFIG_HOME} //
-		($env->{HOME} // '/nonexistent').'/.config')
-		.'/lei/config', $env->{PWD});
+	my ($self) = @_;
+	rel2abs($self, ($self->{env}->{XDG_CONFIG_HOME} //
+		($self->{env}->{HOME} // '/nonexistent').'/.config')
+		.'/lei/config');
 }
 
 # TODO: generate shell completion + help using %CMD and %OPTDESC
 # command => [ positional_args, 1-line description, Getopt::Long option spec ]
 our %CMD = ( # sorted in order of importance/use:
-'query' => [ 'SEARCH_TERMS...', 'search for messages matching terms', qw(
-	save-as=s output|o=s format|f=s dedupe|d=s thread|t augment|a
-	limit|n=i sort|s=s@ reverse|r offset=i remote local! extinbox!
-	since|after=s until|before=s) ],
+'q' => [ 'SEARCH_TERMS...', 'search for messages matching terms', qw(
+	save-as=s output|mfolder|o=s format|f=s dedupe|d=s thread|t augment|a
+	sort|s=s reverse|r offset=i remote! local! external! pretty
+	mua-cmd|mua=s no-torsocks torsocks=s verbose|v quiet|q
+	received-after=s received-before=s sent-after=s sent-since=s),
+	PublicInbox::LeiQuery::curl_opt(), opt_dash('limit|n=i', '[0-9]+') ],
 
 'show' => [ 'MID|OID', 'show a given object (Message-ID or object ID)',
 	qw(type=s solve! format|f=s dedupe|d=s thread|t remote local!),
 	pass_through('git show') ],
 
-'add-extinbox' => [ 'URL_OR_PATHNAME',
+'add-external' => [ 'URL_OR_PATHNAME',
 	'add/set priority of a publicinbox|extindex for extra matches',
-	qw(prio=i) ],
-'ls-extinbox' => [ '[FILTER...]', 'list publicinbox|extindex locations',
-	qw(format|f=s z local remote) ],
-'forget-extinbox' => [ '{URL_OR_PATHNAME|--prune}',
+	qw(boost=i quiet|q) ],
+'ls-external' => [ '[FILTER...]', 'list publicinbox|extindex locations',
+	qw(format|f=s z|0 local remote quiet|q) ],
+'forget-external' => [ 'URL_OR_PATHNAME...|--prune',
 	'exclude further results from a publicinbox|extindex',
-	qw(prune) ],
+	qw(prune quiet|q) ],
 
 'ls-query' => [ '[FILTER...]', 'list saved search queries',
 		qw(name-only format|f=s z) ],
@@ -83,16 +133,16 @@ our %CMD = ( # sorted in order of importance/use:
 	'set/unset flags on message(s) from stdin',
 	qw(stdin| oid=s exact by-mid|mid:s) ],
 'forget' => [ '[--stdin|--oid=OID|--by-mid=MID]',
-	'exclude message(s) on stdin from query results',
+	"exclude message(s) on stdin from `q' search results",
 	qw(stdin| oid=s exact by-mid|mid:s quiet|q) ],
 
-'purge-mailsource' => [ '{URL_OR_PATHNAME|--all}',
+'purge-mailsource' => [ 'URL_OR_PATHNAME|--all',
 	'remove imported messages from IMAP, Maildirs, and MH',
 	qw(exact! all jobs:i indexed) ],
 
 # code repos are used for `show' to solve blobs from patch mails
 'add-coderepo' => [ 'PATHNAME', 'add or set priority of a git code repo',
-	qw(prio=i) ],
+	qw(boost=i) ],
 'ls-coderepo' => [ '[FILTER_TERMS...]',
 		'list known code repos', qw(format|f=s z) ],
 'forget-coderepo' => [ 'PATHNAME',
@@ -109,9 +159,9 @@ our %CMD = ( # sorted in order of importance/use:
 'forget-watch' => [ '{WATCH_NUMBER|--prune}', 'stop and forget a watch',
 	qw(prune) ],
 
-'import' => [ '{URL_OR_PATHNAME|--stdin}',
+'import' => [ 'URL_OR_PATHNAME|--stdin',
 	'one-shot import/update from URL or filesystem',
-	qw(stdin| limit|n=i offset=i recursive|r exclude=s include=s !flags),
+	qw(stdin| offset=i recursive|r exclude=s include=s !flags),
 	],
 
 'config' => [ '[...]', sub {
@@ -121,10 +171,9 @@ our %CMD = ( # sorted in order of importance/use:
 'init' => [ '[PATHNAME]', sub {
 		'initialize storage, default: '._store_path($_[0]);
 	}, qw(quiet|q) ],
-'daemon-stop' => [ '', 'stop the lei-daemon' ],
+'daemon-kill' => [ '[-SIGNAL]', 'signal the lei-daemon',
+	opt_dash('signal|s=s', '[0-9]+|(?:[A-Z][A-Z0-9]+)') ],
 'daemon-pid' => [ '', 'show the PID of the lei-daemon' ],
-'daemon-env' => [ '[NAME=VALUE...]', 'set, unset, or show daemon environment',
-	qw(clear| unset|u=s@ z|0) ],
 'help' => [ '[SUBCOMMAND]', 'show help' ],
 
 # XXX do we need this?
@@ -132,7 +181,11 @@ our %CMD = ( # sorted in order of importance/use:
 
 'reorder-local-store-and-break-history' => [ '[REFNAME]',
 	'rewrite git history in an attempt to improve compression',
-	'gc!' ]
+	'gc!' ],
+
+# internal commands are prefixed with '_'
+'_complete' => [ '[...]', 'internal shell completion helper',
+		pass_through('everything') ],
 ); # @CMD
 
 # switch descriptions, try to keep consistent across commands
@@ -147,38 +200,45 @@ my $ls_format = [ 'OUT|plain|json|null', 'listing output format' ];
 my %OPTDESC = (
 'help|h' => 'show this built-in help',
 'quiet|q' => 'be quiet',
+'verbose|v' => 'be more verbose',
 'solve!' => 'do not attempt to reconstruct blobs from emails',
+'torsocks=s' => ['auto|no|yes',
+		'whether or not to wrap git and curl commands with torsocks'],
+'no-torsocks' => 'alias for --torsocks=no',
 'save-as=s' => ['NAME', 'save a search terms by given name'],
 
 'type=s' => [ 'any|mid|git', 'disambiguate type' ],
 
-'dedupe|d=s' => ['STRAT|content|oid|mid',
+'dedupe|d=s' => ['STRAT|content|oid|mid|none',
 		'deduplication strategy'],
 'show	thread|t' => 'display entire thread a message belongs to',
-'query	thread|t' =>
+'q	thread|t' =>
 	'return all messages in the same thread as the actual match(es)',
 'augment|a' => 'augment --output destination instead of clobbering',
 
-'output|o=s' => [ 'DEST',
+'output|mfolder|o=s' => [ 'DEST',
 	"destination (e.g. `/path/to/Maildir', or `-' for stdout)" ],
+'mua-cmd|mua=s' => [ 'COMMAND',
+	"MUA to run on --output Maildir or mbox (e.g. `mutt -f %f'" ],
 
 'show	format|f=s' => [ 'OUT|plain|raw|html|mboxrd|mboxcl2|mboxcl',
 			'message/object output format' ],
 'mark	format|f=s' => $stdin_formats,
 'forget	format|f=s' => $stdin_formats,
-'query	format|f=s' => [ 'OUT|maildir|mboxrd|mboxcl2|mboxcl|html|oid',
+'q	format|f=s' => [
+	'OUT|maildir|mboxrd|mboxcl2|mboxcl|mboxo|html|json|jsonl|concatjson',
 		'specify output format, default depends on --output'],
 'ls-query	format|f=s' => $ls_format,
-'ls-extinbox	format|f=s' => $ls_format,
+'ls-external	format|f=s' => $ls_format,
 
-'limit|n=i' => ['NUM',
-	'limit on number of matches (default: 10000)' ],
+'limit|n=i@' => ['NUM', 'limit on number of matches (default: 10000)' ],
 'offset=i' => ['OFF', 'search result offset (default: 0)'],
 
-'sort|s=s@' => [ 'VAL|internaldate,date,relevance,docid',
+'sort|s=s' => [ 'VAL|received,relevance,docid',
 		"order of results `--output'-dependent"],
+'reverse|r' => [ 'reverse search results' ], # like sort(1)
 
-'prio=i' => 'priority of query source',
+'boost=i' => 'increase/decrease priority of results (default: 0)',
 
 'local' => 'limit operations to the local filesystem',
 'local!' => 'exclude results from the local filesystem',
@@ -198,58 +258,175 @@ my %OPTDESC = (
 'by-mid|mid:s' => [ 'MID', 'match only by Message-ID, ignoring contents' ],
 'jobs:i' => 'set parallelism level',
 
-# xargs, env, use "-0", git(1) uses "-z".  Should we support z|0 everywhere?
-'z' => 'use NUL \\0 instead of newline (CR) to delimit lines',
+# xargs, env, use "-0", git(1) uses "-z".  We support z|0 everywhere
 'z|0' => 'use NUL \\0 instead of newline (CR) to delimit lines',
 
-# note: no "--ignore-environment" / "-i" support like env(1) since that
-# is one-shot and this is for a persistent daemon:
-'clear|' => 'clear the daemon environment',
-'unset|u=s@' => ['NAME',
-	'unset matching NAME, may be specified multiple times'],
+'signal|s=s' => [ 'SIG', 'signal to send lei-daemon (default: TERM)' ],
 ); # %OPTDESC
 
-sub x_it ($$) { # pronounced "exit"
+my %CONFIG_KEYS = (
+	'leistore.dir' => 'top-level storage location',
+);
+
+# pronounced "exit": x_it(1 << 8) => exit(1); x_it(13) => SIGPIPE
+sub x_it ($$) {
 	my ($self, $code) = @_;
-	if (my $sig = ($code & 127)) {
-		kill($sig, $self->{pid} // $$);
-	} else {
-		$code >>= 8;
-		if (my $sock = $self->{sock}) {
-			say $sock "exit=$code";
-		} else { # for oneshot
-			$quit->($code);
+	# make sure client sees stdout before exit
+	$self->{1}->autoflush(1) if $self->{1};
+	dump_and_clear_log();
+	if (my $sock = $self->{sock}) {
+		send($sock, "x_it $code", MSG_EOR);
+	} elsif (my $signum = ($code & 127)) { # oneshot, usually SIGPIPE (13)
+		$SIG{PIPE} = 'DEFAULT'; # $SIG{$signum} doesn't work
+		kill $signum, $$;
+		sleep; # wait for signal
+	} else { # oneshot
+		# don't want to end up using $? from child processes
+		for my $f (qw(lxs l2m)) {
+			my $wq = delete $self->{$f} or next;
+			$wq->DESTROY;
 		}
+		$quit->($code >> 8);
 	}
 }
 
-sub emit {
-	my ($self, $channel) = @_; # $buf = $_[2]
-	print { $self->{$channel} } $_[2] or die "print FD[$channel]: $!";
+sub err ($;@) {
+	my $self = shift;
+	my $err = $self->{2} // ($self->{pgr} // [])->[2] // *STDERR{GLOB};
+	my $eor = (substr($_[-1], -1, 1) eq "\n" ? () : "\n");
+	print $err @_, $eor and return;
+	my $old_err = delete $self->{2};
+	close($old_err) if $! == EPIPE && $old_err;;
+	$err = $self->{2} = ($self->{pgr} // [])->[2] // *STDERR{GLOB};
+	print $err @_, $eor or print STDERR @_, $eor;
 }
 
-sub err {
-	my ($self, $buf) = @_;
-	$buf .= "\n" unless $buf =~ /\n\z/s;
-	emit($self, 2, $buf);
-}
-
-sub qerr { $_[0]->{opt}->{quiet} or err(@_) }
+sub qerr ($;@) { $_[0]->{opt}->{quiet} or err(shift, @_) }
 
 sub fail ($$;$) {
 	my ($self, $buf, $exit_code) = @_;
-	err($self, $buf);
+	err($self, $buf) if defined $buf;
+	send($self->{pkt_op}, '!', MSG_EOR) if $self->{pkt_op}; # fail_handler
 	x_it($self, ($exit_code // 1) << 8);
 	undef;
 }
 
+sub out ($;@) {
+	my $self = shift;
+	return if print { $self->{1} // return } @_; # likely
+	return note_sigpipe($self, 1) if $! == EPIPE;
+	my $err = "error writing to stdout: $!";
+	delete $self->{1};
+	fail($self, $err);
+}
+
+sub puts ($;@) { out(shift, map { "$_\n" } @_) }
+
+sub child_error { # passes non-fatal curl exit codes to user
+	my ($self, $child_error) = @_; # child_error is $?
+	if (my $sock = $self->{sock}) { # send to lei(1) client
+		send($sock, "child_error $child_error", MSG_EOR);
+	} else { # oneshot
+		$self->{child_error} = $child_error;
+	}
+	undef;
+}
+
+sub atfork_prepare_wq {
+	my ($self, $wq) = @_;
+	my $tcafc = $wq->{-ipc_atfork_child_close} //= [ $listener // () ];
+	if (my $sock = $self->{sock}) {
+		push @$tcafc, @$self{qw(0 1 2 3)}, $sock;
+	}
+	if (my $pgr = $self->{pgr}) {
+		push @$tcafc, @$pgr[1,2];
+	}
+	if (my $old_1 = $self->{old_1}) {
+		push @$tcafc, $old_1;
+	}
+	for my $f (qw(lxs l2m)) {
+		my $ipc = $self->{$f} or next;
+		push @$tcafc, grep { defined }
+				@$ipc{qw(-wq_s1 -wq_s2 -ipc_req -ipc_res)};
+	}
+}
+
+sub io_restore ($$) {
+	my ($dst, $src) = @_;
+	for my $i (0..2) { # standard FDs
+		my $io = delete $src->{$i} or next;
+		$dst->{$i} = $io;
+	}
+	for my $i (3..9) { # named (non-standard) FDs
+		my $io = $src->{$i} or next;
+		my @st = stat($io) or die "stat $src.$i ($io): $!";
+		my $f = delete $dst->{"dev=$st[0],ino=$st[1]"} // next;
+		$dst->{$f} = $io;
+		delete $src->{$i};
+	}
+}
+
+sub note_sigpipe { # triggers sigpipe_handler
+	my ($self, $fd) = @_;
+	close(delete($self->{$fd})); # explicit close silences Perl warning
+	send($self->{pkt_op}, '|', MSG_EOR) if $self->{pkt_op};
+	x_it($self, 13);
+}
+
+sub atfork_child_wq {
+	my ($self, $wq) = @_;
+	io_restore($self, $wq);
+	-S $self->{pkt_op} or die 'BUG: {pkt_op} expected';
+	io_restore($self->{l2m}, $wq);
+	%PATH2CFG = ();
+	undef $errors_log;
+	$quit = \&CORE::exit;
+	$current_lei = $self; # for SIG{__WARN__}
+}
+
+sub io_extract ($;@) {
+	my ($obj, @fields) = @_;
+	my @io;
+	for my $f (@fields) {
+		my $io = delete $obj->{$f} or next;
+		my @st = stat($io) or die "W: stat $obj.$f ($io): $!";
+		$obj->{"dev=$st[0],ino=$st[1]"} = $f;
+		push @io, $io;
+	}
+	@io
+}
+
+# usage: ($lei, @io) = $lei->atfork_parent_wq($wq);
+sub atfork_parent_wq {
+	my ($self, $wq) = @_;
+	my $env = delete $self->{env}; # env is inherited at fork
+	my $lei = bless { %$self }, ref($self);
+	for my $f (qw(dedupe ovv)) {
+		my $tmp = delete($lei->{$f}) or next;
+		$lei->{$f} = $wq->deep_clone($tmp);
+	}
+	$self->{env} = $env;
+	delete @$lei{qw(3 -lei_store cfg old_1 pgr lxs)}; # keep l2m
+	my @io = (delete(@$lei{qw(0 1 2)}),
+			io_extract($lei, qw(sock pkt_op startq)));
+	my $l2m = $lei->{l2m};
+	if ($l2m && $l2m != $wq) { # $wq == lxs
+		if (my $wq_s1 = $l2m->{-wq_s1}) {
+			push @io, io_extract($l2m, '-wq_s1');
+			$l2m->{-wq_s1} = $wq_s1;
+		}
+		$l2m->wq_close(1);
+	}
+	($lei, @io);
+}
+
 sub _help ($;$) {
 	my ($self, $errmsg) = @_;
 	my $cmd = $self->{cmd} // 'COMMAND';
 	my @info = @{$CMD{$cmd} // [ '...', '...' ]};
 	my @top = ($cmd, shift(@info) // ());
 	my $cmd_desc = shift(@info);
-	$cmd_desc = $cmd_desc->($self->{env}) if ref($cmd_desc) eq 'CODE';
+	$cmd_desc = $cmd_desc->($self) if ref($cmd_desc) eq 'CODE';
 	my @opt_desc;
 	my $lpad = 2;
 	for my $sw (grep { !ref } @info) { # ("prio=s", "z", $GLP_PASS)
@@ -314,8 +491,7 @@ EOF
 		$msg .= $rhs;
 		$msg .= "\n";
 	}
-	my $channel = $errmsg ? 2 : 1;
-	emit($self, $channel, $msg);
+	print { $self->{$errmsg ? 2 : 1} } $msg;
 	x_it($self, $errmsg ? 1 << 8 : 0); # stderr => failure
 	undef;
 }
@@ -323,23 +499,25 @@ EOF
 sub optparse ($$$) {
 	my ($self, $cmd, $argv) = @_;
 	$self->{cmd} = $cmd;
-	my $opt = $self->{opt} = {};
+	$OPT = $self->{opt} = {};
 	my $info = $CMD{$cmd} // [ '[...]' ];
 	my ($proto, undef, @spec) = @$info;
-	my $glp = ref($spec[-1]) ? pop(@spec) : $GLP; # or $GLP_PASS
+	my $glp = ref($spec[-1]) eq ref($GLP) ? pop(@spec) : $GLP;
 	push @spec, qw(help|h);
 	my $lone_dash;
 	if ($spec[0] =~ s/\|\z//s) { # "stdin|" or "clear|" allows "-" alias
 		$lone_dash = $spec[0];
-		$opt->{$spec[0]} = \(my $var);
+		$OPT->{$spec[0]} = \(my $var);
 		push @spec, '' => \$var;
 	}
-	$glp->getoptionsfromarray($argv, $opt, @spec) or
+	$glp->getoptionsfromarray($argv, $OPT, @spec) or
 		return _help($self, "bad arguments or options for $cmd");
-	return _help($self) if $opt->{help};
+	return _help($self) if $OPT->{help};
+
+	push @$argv, @{$OPT->{-argv}} if defined($OPT->{-argv});
 
 	# "-" aliases "stdin" or "clear"
-	$opt->{$lone_dash} = ${$opt->{$lone_dash}} if defined $lone_dash;
+	$OPT->{$lone_dash} = ${$OPT->{$lone_dash}} if defined $lone_dash;
 
 	my $i = 0;
 	my $POS_ARG = '[A-Z][A-Z0-9_]+';
@@ -355,14 +533,14 @@ sub optparse ($$$) {
 		} elsif ($var =~ /\.\.\.\]\z/) { # optional args start
 			$inf = 1;
 			last;
-		} elsif ($var =~ /\A\[$POS_ARG\]\z/) { # one optional arg
+		} elsif ($var =~ /\A\[-?$POS_ARG\]\z/) { # one optional arg
 			$i++;
 		} elsif ($var =~ /\A.+?\|/) { # required FOO|--stdin
 			my @or = split(/\|/, $var);
 			my $ok;
 			for my $o (@or) {
 				if ($o =~ /\A--([a-z0-9\-]+)/) {
-					$ok = defined($opt->{$1});
+					$ok = defined($OPT->{$1});
 					last;
 				} elsif (defined($argv->[$i])) {
 					$ok = 1;
@@ -370,6 +548,7 @@ sub optparse ($$$) {
 					last;
 				} # else continue looping
 			}
+			last if $ok;
 			my $last = pop @or;
 			$err = join(', ', @or) . " or $last must be set";
 		} else {
@@ -377,7 +556,6 @@ sub optparse ($$$) {
 		}
 		last if $err;
 	}
-	# warn "inf=$inf ".scalar(@$argv). ' '.scalar(@args)."\n";
 	if (!$inf && scalar(@$argv) > scalar(@args)) {
 		$err //= 'too many arguments';
 	}
@@ -386,7 +564,8 @@ sub optparse ($$$) {
 
 sub dispatch {
 	my ($self, $cmd, @argv) = @_;
-	local $SIG{__WARN__} = sub { err($self, "@_") };
+	local $current_lei = $self; # for __WARN__
+	dump_and_clear_log("from previous run\n");
 	return _help($self, 'no command given') unless defined($cmd);
 	my $func = "lei_$cmd";
 	$func =~ tr/-/_/;
@@ -405,7 +584,7 @@ sub dispatch {
 
 sub _lei_cfg ($;$) {
 	my ($self, $creat) = @_;
-	my $f = _config_path($self->{env});
+	my $f = _config_path($self);
 	my @st = stat($f);
 	my $cur_st = @st ? pack('dd', $st[10], $st[7]) : ''; # 10:ctime, 7:size
 	if (my $cfg = $PATH2CFG{$f}) { # reuse existing object in common case
@@ -434,8 +613,8 @@ sub _lei_store ($;$) {
 	my $cfg = _lei_cfg($self, $creat);
 	$cfg->{-lei_store} //= do {
 		require PublicInbox::LeiStore;
-		PublicInbox::SearchIdx::load_xapian_writable();
-		defined(my $dir = $cfg->{'leistore.dir'}) or return;
+		my $dir = $cfg->{'leistore.dir'};
+		$dir //= $creat ? _store_path($self) : return;
 		PublicInbox::LeiStore->new($dir, { creat => $creat });
 	};
 }
@@ -444,36 +623,37 @@ sub lei_show {
 	my ($self, @argv) = @_;
 }
 
-sub lei_query {
-	my ($self, @argv) = @_;
-}
-
 sub lei_mark {
 	my ($self, @argv) = @_;
 }
 
-sub lei_config {
+sub _config {
 	my ($self, @argv) = @_;
-	$self->{opt}->{'config-file'} and return fail $self,
-		"config file switches not supported by `lei config'";
 	my $env = $self->{env};
 	delete local $env->{GIT_CONFIG};
+	delete local $ENV{GIT_CONFIG};
 	my $cfg = _lei_cfg($self, 1);
 	my $cmd = [ qw(git config -f), $cfg->{'-f'}, @argv ];
 	my %rdr = map { $_ => $self->{$_} } (0..2);
-	require PublicInbox::Import;
-	PublicInbox::Import::run_die($cmd, $env, \%rdr);
+	waitpid(spawn($cmd, $env, \%rdr), 0);
+}
+
+sub lei_config {
+	my ($self, @argv) = @_;
+	$self->{opt}->{'config-file'} and return fail $self,
+		"config file switches not supported by `lei config'";
+	_config(@_);
+	x_it($self, $?) if $?;
 }
 
 sub lei_init {
 	my ($self, $dir) = @_;
 	my $cfg = _lei_cfg($self, 1);
 	my $cur = $cfg->{'leistore.dir'};
-	my $env = $self->{env};
-	$dir //= _store_path($env);
-	$dir = File::Spec->rel2abs($dir, $env->{PWD}); # PWD is symlink-aware
+	$dir //= _store_path($self);
+	$dir = rel2abs($self, $dir);
 	my @cur = stat($cur) if defined($cur);
-	$cur = File::Spec->canonpath($cur) if $cur;
+	$cur = File::Spec->canonpath($cur // $dir);
 	my @dir = stat($dir);
 	my $exists = "I: leistore.dir=$cur already initialized" if @dir;
 	if (@cur) {
@@ -483,7 +663,7 @@ sub lei_init {
 		}
 
 		# some folks like symlinks and bind mounts :P
-		if (@dir && "$cur[0] $cur[1]" eq "$dir[0] $dir[1]") {
+		if (@dir && "@cur[1,0]" eq "@dir[1,0]") {
 			lei_config($self, 'leistore.dir', $dir);
 			_lei_store($self, 1)->done;
 			return qerr($self, "$exists (as $cur)");
@@ -498,130 +678,307 @@ E: leistore.dir=$cur already initialized and it is not $dir
 	return qerr($self, $exists);
 }
 
-sub lei_daemon_pid { emit($_[0], 1, "$$\n") }
+sub lei_daemon_pid { puts shift, $$ }
 
-sub lei_daemon_stop { $quit->(0) }
+sub lei_daemon_kill {
+	my ($self) = @_;
+	my $sig = $self->{opt}->{signal} // 'TERM';
+	kill($sig, $$) or fail($self, "kill($sig, $$): $!");
+}
 
-sub lei_daemon_env {
-	my ($self, @argv) = @_;
-	my $opt = $self->{opt};
-	if (defined $opt->{clear}) {
-		%ENV = ();
-	} elsif (my $u = $opt->{unset}) {
-		delete @ENV{@$u};
+sub lei_help { _help($_[0]) }
+
+# Shell completion helper.  Used by lei-completion.bash and hopefully
+# other shells.  Try to do as much here as possible to avoid redundancy
+# and improve maintainability.
+sub lei__complete {
+	my ($self, @argv) = @_; # argv = qw(lei and any other args...)
+	shift @argv; # ignore "lei", the entire command is sent
+	@argv or return puts $self, grep(!/^_/, keys %CMD), qw(--help -h);
+	my $cmd = shift @argv;
+	my $info = $CMD{$cmd} // do { # filter matching commands
+		@argv or puts $self, grep(/\A\Q$cmd\E/, keys %CMD);
+		return;
+	};
+	my ($proto, undef, @spec) = @$info;
+	my $cur = pop @argv;
+	my $re = defined($cur) ? qr/\A\Q$cur\E/ : qr/./;
+	if (substr($cur // '-', 0, 1) eq '-') { # --switches
+		# gross special case since the only git-config options
+		# Consider moving to a table if we need more special cases
+		# we use Getopt::Long for are the ones we reject, so these
+		# are the ones we don't reject:
+		if ($cmd eq 'config') {
+			puts $self, grep(/$re/, keys %CONFIG_KEYS);
+			@spec = qw(add z|null get get-all unset unset-all
+				replace-all get-urlmatch
+				remove-section rename-section
+				name-only list|l edit|e
+				get-color-name get-colorbool);
+			# fall-through
+		}
+		puts $self, grep(/$re/, map { # generate short/long names
+			if (s/[:=].+\z//) { # req/optional args, e.g output|o=i
+			} else { # negation: solve! => no-solve|solve
+				s/\A(.+)!\z/no-$1|$1/;
+			}
+			map {
+				my $x = length > 1 ? "--$_" : "-$_";
+				$x eq $cur ? () : $x;
+			} split(/\|/, $_, -1) # help|h
+		} grep { $OPTDESC{"$cmd\t$_"} || $OPTDESC{$_} } @spec);
+	} elsif ($cmd eq 'config' && !@argv && !$CONFIG_KEYS{$cur}) {
+		puts $self, grep(/$re/, keys %CONFIG_KEYS);
+	}
+
+	# switch args (e.g. lei q -f mbox<TAB>)
+	if (($argv[-1] // $cur // '') =~ /\A--?([\w\-]+)\z/) {
+		my $opt = quotemeta $1;
+		puts $self, map {
+			my $v = $OPTDESC{$_};
+			$v = $v->[0] if ref($v);
+			my @v = split(/\|/, $v);
+			# get rid of ALL CAPS placeholder (e.g "OUT")
+			# (TODO: completion for external paths)
+			shift(@v) if uc($v[0]) eq $v[0];
+			@v;
+		} grep(/\A(?:$cmd\t|)(?:[\w-]+\|)*$opt\b/, keys %OPTDESC);
 	}
-	if (@argv) {
-		%ENV = (%ENV, map { split(/=/, $_, 2) } @argv);
-	} elsif (!defined($opt->{clear}) && !$opt->{unset}) {
-		my $eor = $opt->{z} ? "\0" : "\n";
-		my $buf = '';
-		while (my ($k, $v) = each %ENV) { $buf .= "$k=$v$eor" }
-		emit($self, 1, $buf)
+	$cmd =~ tr/-/_/;
+	if (my $sub = $self->can("_complete_$cmd")) {
+		puts $self, $sub->($self, @argv, $cur);
 	}
+	# TODO: URLs, pathnames, OIDs, MIDs, etc...  See optparse() for
+	# proto parsing.
 }
 
-sub lei_help { _help($_[0]) }
+sub exec_buf ($$) {
+	my ($argv, $env) = @_;
+	my $argc = scalar @$argv;
+	my $buf = 'exec '.join("\0", scalar(@$argv), @$argv);
+	while (my ($k, $v) = each %$env) { $buf .= "\0$k=$v" };
+	$buf;
+}
 
-sub reap_exec { # dwaitpid callback
-	my ($self, $pid) = @_;
-	x_it($self, $?);
+sub start_mua {
+	my ($self) = @_;
+	my $mua = $self->{opt}->{'mua-cmd'} // return;
+	my $mfolder = $self->{ovv}->{dst};
+	my (@cmd, $replaced);
+	if ($mua =~ /\A(?:mutt|mailx|mail|neomutt)\z/) {
+		@cmd = ($mua, '-f');
+	# TODO: help wanted: other common FOSS MUAs
+	} else {
+		require Text::ParseWords;
+		my @cmd = Text::ParseWords::shellwords($mua);
+		# mutt uses '%f' for open-hook with compressed mbox, we follow
+		@cmd = map { $_ eq '%f' ? ($replaced = $mfolder) : $_ } @cmd;
+	}
+	push @cmd, $mfolder unless defined($replaced);
+	if (my $sock = $self->{sock}) { # lei(1) client process runs it
+		send($sock, exec_buf(\@cmd, {}), MSG_EOR);
+	} else { # oneshot
+		$self->{"mua.pid.$self.$$"} = spawn(\@cmd);
+	}
 }
 
-sub lei_git { # support passing through random git commands
-	my ($self, @argv) = @_;
-	my %rdr = map { $_ => $self->{$_} } (0..2);
-	my $pid = spawn(['git', @argv], $self->{env}, \%rdr);
-	PublicInbox::DS::dwaitpid($pid, \&reap_exec, $self);
+# caller needs to "-t $self->{1}" to check if tty
+sub start_pager {
+	my ($self) = @_;
+	my $env = $self->{env};
+	my $fh = popen_rd([qw(git var GIT_PAGER)], $env);
+	chomp(my $pager = <$fh> // '');
+	close($fh) or warn "`git var PAGER' error: \$?=$?";
+	return if $pager eq 'cat' || $pager eq '';
+	# TODO TIOCGWINSZ
+	my $new_env = { LESS => 'FRX', LV => '-c', COLUMNS => 80 };
+	$new_env->{MORE} = 'FRX' if $^O eq 'freebsd';
+	pipe(my ($r, $wpager)) or return warn "pipe: $!";
+	my $rdr = { 0 => $r, 1 => $self->{1}, 2 => $self->{2} };
+	my $pgr = [ undef, @$rdr{1, 2}, $$ ];
+	if (my $sock = $self->{sock}) { # lei(1) process runs it
+		delete @$new_env{keys %$env}; # only set iff unset
+		my $fds = [ map { fileno($_) } @$rdr{0..2} ];
+		$send_cmd->($sock, $fds, exec_buf([$pager], $new_env), MSG_EOR);
+	} else {
+		$pgr->[0] = spawn([$pager], $new_env, $rdr);
+	}
+	$self->{1} = $wpager;
+	$self->{2} = $wpager if -t $self->{2};
+	$env->{GIT_PAGER_IN_USE} = 'true'; # we may spawn git
+	$self->{pgr} = $pgr;
+}
+
+sub stop_pager {
+	my ($self) = @_;
+	my $pgr = delete($self->{pgr}) or return;
+	$self->{2} = $pgr->[2];
+	# do not restore original stdout, just close it so we error out
+	close(delete($self->{1})) if $self->{1};
+	my $pid = $pgr->[0];
+	dwaitpid($pid, undef, $self->{sock}) if $pid && $pgr->[3] == $$;
 }
 
 sub accept_dispatch { # Listener {post_accept} callback
 	my ($sock) = @_; # ignore other
-	$sock->blocking(1);
 	$sock->autoflush(1);
 	my $self = bless { sock => $sock }, __PACKAGE__;
-	vec(my $rin = '', fileno($sock), 1) = 1;
-	# `say $sock' triggers "die" in lei(1)
-	for my $i (0..2) {
-		if (select(my $rout = $rin, undef, undef, 1)) {
-			my $fd = IO::FDPass::recv(fileno($sock));
-			if ($fd >= 0) {
-				my $rdr = ($fd == 0 ? '<&=' : '>&=');
-				if (open(my $fh, $rdr, $fd)) {
-					$self->{$i} = $fh;
-				} else {
-					say $sock "open($rdr$fd) (FD=$i): $!";
-					return;
-				}
-			} else {
-				say $sock "recv FD=$i: $!";
-				return;
-			}
-		} else {
-			say $sock "timed out waiting to recv FD=$i";
-			return;
+	vec(my $rvec = '', fileno($sock), 1) = 1;
+	select($rvec, undef, undef, 60) or
+		return send($sock, 'timed out waiting to recv FDs', MSG_EOR);
+	my @fds = $recv_cmd->($sock, my $buf, 4096 * 33); # >MAX_ARG_STRLEN
+	if (scalar(@fds) == 4) {
+		for my $i (0..3) {
+			my $fd = shift(@fds);
+			open($self->{$i}, '+<&=', $fd) and next;
+			send($sock, "open(+<&=$fd) (FD=$i): $!", MSG_EOR);
 		}
+	} else {
+		my $msg = "recv_cmd failed: $!";
+		warn $msg;
+		return send($sock, $msg, MSG_EOR);
 	}
-	# $ARGV_STR = join("]\0[", @ARGV);
-	# $ENV_STR = join('', map { "$_=$ENV{$_}\0" } keys %ENV);
-	# $line = "$$\0\0>$ARGV_STR\0\0>$ENV_STR\0\0";
-	my ($client_pid, $argv, $env) = do {
-		local $/ = "\0\0\0"; # yes, 3 NULs at EOL, not 2
-		chomp(my $line = <$sock>);
-		split(/\0\0>/, $line, 3);
-	};
-	my %env = map { split(/=/, $_, 2) } split(/\0/, $env);
-	if (chdir($env{PWD})) {
+	$self->{2}->autoflush(1); # keep stdout buffered until x_it|DESTROY
+	# $ENV_STR = join('', map { "\0$_=$ENV{$_}" } keys %ENV);
+	# $buf = "$argc\0".join("\0", @ARGV).$ENV_STR."\0\0";
+	substr($buf, -2, 2, '') eq "\0\0" or  # s/\0\0\z//
+		return send($sock, 'request command truncated', MSG_EOR);
+	my ($argc, @argv) = split(/\0/, $buf, -1);
+	undef $buf;
+	my %env = map { split(/=/, $_, 2) } splice(@argv, $argc);
+	if (chdir($self->{3})) {
+		local %ENV = %env;
 		$self->{env} = \%env;
-		$self->{pid} = $client_pid;
-		eval { dispatch($self, split(/\]\0\[/, $argv)) };
-		say $sock $@ if $@;
+		eval { dispatch($self, @argv) };
+		send($sock, $@, MSG_EOR) if $@;
 	} else {
-		say $sock "chdir($env{PWD}): $!"; # implicit close
+		send($sock, "fchdir: $!", MSG_EOR); # implicit close
+	}
+}
+
+sub dclose {
+	my ($self) = @_;
+	for my $f (qw(lxs l2m)) {
+		my $wq = delete $self->{$f} or next;
+		if ($wq->wq_kill) {
+			$wq->wq_close
+		} elsif ($wq->wq_kill_old) {
+			$wq->wq_wait_old($self);
+		}
+	}
+	close(delete $self->{1}) if $self->{1}; # may reap_compress
+	$self->close if $self->{sock}; # PublicInbox::DS::close
+}
+
+# for long-running results
+sub event_step {
+	my ($self) = @_;
+	local %ENV = %{$self->{env}};
+	my $sock = $self->{sock};
+	local $current_lei = $self;
+	eval {
+		while (my @fds = $recv_cmd->($sock, my $buf, 4096)) {
+			if (scalar(@fds) == 1 && !defined($fds[0])) {
+				return if $! == EAGAIN;
+				next if $! == EINTR;
+				last if $! == ECONNRESET;
+				die "recvmsg: $!";
+			}
+			for my $fd (@fds) {
+				open my $rfh, '+<&=', $fd;
+			}
+			die "unrecognized client signal: $buf";
+		}
+		dclose($self);
+	};
+	if (my $err = $@) {
+		eval { $self->fail($err) };
+		dclose($self);
+	}
+}
+
+sub event_step_init {
+	my ($self) = @_;
+	if (my $sock = $self->{sock}) { # using DS->EventLoop
+		$self->SUPER::new($sock, EPOLLIN|EPOLLET);
 	}
 }
 
 sub noop {}
 
+our $oldset; sub oldset { $oldset }
+
+sub dump_and_clear_log {
+	if (defined($errors_log) && -s STDIN && seek(STDIN, 0, SEEK_SET)) {
+		my @pfx = @_;
+		unshift(@pfx, "$errors_log ") if @pfx;
+		warn @pfx, do { local $/; <STDIN> };
+		truncate(STDIN, 0) or warn "ftruncate ($errors_log): $!";
+	}
+}
+
 # lei(1) calls this when it can't connect
 sub lazy_start {
-	my ($path, $errno) = @_;
+	my ($path, $errno, $narg) = @_;
 	if ($errno == ECONNREFUSED) {
 		unlink($path) or die "unlink($path): $!";
 	} elsif ($errno != ENOENT) {
 		$! = $errno; # allow interpolation to stringify in die
 		die "connect($path): $!";
 	}
+	if (eval { require BSD::Resource }) {
+		my $NOFILE = BSD::Resource::RLIMIT_NOFILE();
+		my ($s, $h) = BSD::Resource::getrlimit($NOFILE);
+		BSD::Resource::setrlimit($NOFILE, $h, $h) if $s < $h;
+	}
 	umask(077) // die("umask(077): $!");
-	socket(my $l, AF_UNIX, SOCK_STREAM, 0) or die "socket: $!";
-	bind($l, pack_sockaddr_un($path)) or die "bind($path): $!";
-	listen($l, 1024) or die "listen: $!";
+	local $listener;
+	socket($listener, AF_UNIX, SOCK_SEQPACKET, 0) or die "socket: $!";
+	bind($listener, pack_sockaddr_un($path)) or die "bind($path): $!";
+	listen($listener, 1024) or die "listen: $!";
 	my @st = stat($path) or die "stat($path): $!";
 	my $dev_ino_expect = pack('dd', $st[0], $st[1]); # dev+ino
-	pipe(my ($eof_r, $eof_w)) or die "pipe: $!";
-	my $oldset = PublicInbox::Sigfd::block_signals();
-	require IO::FDPass;
+	local $oldset = PublicInbox::DS::block_signals();
+	if ($narg == 5) {
+		$send_cmd = PublicInbox::Spawn->can('send_cmd4');
+		$recv_cmd = PublicInbox::Spawn->can('recv_cmd4') // do {
+			require PublicInbox::CmdIPC4;
+			$send_cmd = PublicInbox::CmdIPC4->can('send_cmd4');
+			PublicInbox::CmdIPC4->can('recv_cmd4');
+		};
+	}
+	$recv_cmd or die <<"";
+(Socket::MsgHdr || Inline::C) missing/unconfigured (narg=$narg);
+
 	require PublicInbox::Listener;
 	require PublicInbox::EOFpipe;
-	(-p STDOUT && -p STDERR) or die "E: stdout+stderr must be pipes\n";
-	open(STDIN, '+<', '/dev/null') or die "redirect stdin failed: $!";
+	(-p STDOUT) or die "E: stdout must be a pipe\n";
+	local $errors_log;
+	($errors_log) = ($path =~ m!\A(.+?/)[^/]+\z!);
+	$errors_log .= 'errors.log';
+	open(STDIN, '+>>', $errors_log) or die "open($errors_log): $!";
+	STDIN->autoflush(1);
+	dump_and_clear_log("from previous daemon process:\n");
 	POSIX::setsid() > 0 or die "setsid: $!";
 	my $pid = fork // die "fork: $!";
 	return if $pid;
 	$0 = "lei-daemon $path";
 	local %PATH2CFG;
-	$_->blocking(0) for ($l, $eof_r, $eof_w);
-	$l = PublicInbox::Listener->new($l, \&accept_dispatch, $l);
+	$listener->blocking(0);
 	my $exit_code;
-	local $quit = sub {
-		$exit_code //= shift;
-		my $listener = $l or exit($exit_code);
-		unlink($path) if defined($path);
-		# closing eof_w triggers \&noop wakeup
-		$eof_w = $l = $path = undef;
-		$listener->close; # DS::close
-		PublicInbox::DS->SetLoopTimeout(1000);
+	my $pil = PublicInbox::Listener->new($listener, \&accept_dispatch);
+	local $quit = do {
+		pipe(my ($eof_r, $eof_w)) or die "pipe: $!";
+		PublicInbox::EOFpipe->new($eof_r, \&noop, undef);
+		sub {
+			$exit_code //= shift;
+			my $lis = $pil or exit($exit_code);
+			# closing eof_w triggers \&noop wakeup
+			$listener = $eof_w = $pil = $path = undef;
+			$lis->close; # DS::close
+			PublicInbox::DS->SetLoopTimeout(1000);
+		};
 	};
-	PublicInbox::EOFpipe->new($eof_r, \&noop, undef);
 	my $sig = {
 		CHLD => \&PublicInbox::DS::enqueue_reap,
 		QUIT => $quit,
@@ -631,14 +988,17 @@ sub lazy_start {
 		USR1 => \&noop,
 		USR2 => \&noop,
 	};
-	my $sigfd = PublicInbox::Sigfd->new($sig, $SFD_NONBLOCK);
-	local %SIG = (%SIG, %$sig) if !$sigfd;
+	my $sigfd = PublicInbox::Sigfd->new($sig, SFD_NONBLOCK);
+	local @SIG{keys %$sig} = values(%$sig) unless $sigfd;
+	undef $sig;
+	local $SIG{PIPE} = 'IGNORE';
 	if ($sigfd) { # TODO: use inotify/kqueue to detect unlinked sockets
+		undef $sigfd;
 		PublicInbox::DS->SetLoopTimeout(5000);
 	} else {
 		# wake up every second to accept signals if we don't
 		# have signalfd or IO::KQueue:
-		PublicInbox::Sigfd::sig_setmask($oldset);
+		PublicInbox::DS::sig_setmask($oldset);
 		PublicInbox::DS->SetLoopTimeout(1000);
 	}
 	PublicInbox::DS->SetPostLoopCallback(sub {
@@ -648,9 +1008,9 @@ sub lazy_start {
 				warn "$path dev/ino changed, quitting\n";
 				$path = undef;
 			}
-		} elsif (defined($path)) {
-			warn "stat($path): $!, quitting ...\n";
-			undef $path; # don't unlink
+		} elsif (defined($path)) { # ENOENT is common
+			warn "stat($path): $!, quitting ...\n" if $! != ENOENT;
+			undef $path;
 			$quit->();
 		}
 		return 1 if defined($path);
@@ -667,36 +1027,46 @@ sub lazy_start {
 		$n; # true: continue, false: stop
 	});
 
-	# STDIN was redirected to /dev/null above, closing STDOUT and
-	# STDERR will cause the calling `lei' client process to finish
-	# reading <$daemon> pipe.
-	open STDOUT, '>&STDIN' or die "redirect stdout failed: $!";
-	openlog($path, 'pid', 'user');
-	local $SIG{__WARN__} = sub { syslog('warning', "@_") };
-	my $owner_pid = $$;
-	my $on_destroy = PublicInbox::OnDestroy->new(sub {
-		syslog('crit', "$@") if $@ && $$ == $owner_pid;
-	});
+	# STDIN was redirected to /dev/null above, closing STDERR and
+	# STDOUT will cause the calling `lei' client process to finish
+	# reading the <$daemon> pipe.
+	local $SIG{__WARN__} = sub {
+		$current_lei ? err($current_lei, @_) : warn(
+		  strftime('%Y-%m-%dT%H:%M:%SZ', gmtime(time))," $$ ", @_);
+	};
 	open STDERR, '>&STDIN' or die "redirect stderr failed: $!";
+	open STDOUT, '>&STDIN' or die "redirect stdout failed: $!";
 	# $daemon pipe to `lei' closed, main loop begins:
 	PublicInbox::DS->EventLoop;
-	@$on_destroy = (); # cancel on_destroy if we get here
 	exit($exit_code // 0);
 }
 
-# for users w/o IO::FDPass
+# for users w/o Socket::Msghdr installed or Inline::C enabled
 sub oneshot {
 	my ($main_pkg) = @_;
 	my $exit = $main_pkg->can('exit'); # caller may override exit()
 	local $quit = $exit if $exit;
 	local %PATH2CFG;
 	umask(077) // die("umask(077): $!");
-	dispatch((bless {
-		0 => *STDIN{IO},
-		1 => *STDOUT{IO},
-		2 => *STDERR{IO},
+	my $self = bless {
+		0 => *STDIN{GLOB},
+		1 => *STDOUT{GLOB},
+		2 => *STDERR{GLOB},
 		env => \%ENV
-	}, __PACKAGE__), @ARGV);
+	}, __PACKAGE__;
+	dispatch($self, @ARGV);
+	x_it($self, $self->{child_error}) if $self->{child_error};
+}
+
+# ensures stdout hits the FS before sock disconnects so a client
+# can immediately reread it
+sub DESTROY {
+	my ($self) = @_;
+	$self->{1}->autoflush(1) if $self->{1};
+	stop_pager($self);
+	if (my $mua_pid = delete $self->{"mua.pid.$self.$$"}) {
+		waitpid($mua_pid, 0);
+	}
 }
 
 1;