i3status-wrapper: swap parent and child processes

This should ensure the filtering loop stays alive in more circumstances.

1 files changed, 84 insertions, 84 deletions

diff --git a/scripts/desktop/i3status-wrapper b/scripts/desktop/i3status-wrapper
index 91f83032..0f8f96ec 100755
--- a/scripts/desktop/i3status-wrapper
+++ b/scripts/desktop/i3status-wrapper
@@ -42,108 +42,108 @@ unless ($i3status) {
 
 tie my %info, "IPC::Shareable", undef, { destroy => 1 };
 
-unless (fork // die "couldn't fork()!") {
-    $pipe->reader;
-    open STDIN, "<&=", $pipe->fileno
-      or die "couldn't reopen child's STDIN!";
+unless (fork // warn "couldn't fork monitoring loop") {
+    my $caffeinated_id;
 
-    # Following based on Michael Stapelberg's sample i3status-wrapper script.
+    open my $events, "-|",
+      $wmipc, "-t", "subscribe", "-m", '[ "window", "workspace" ]';
 
-    my $hostname = hostname;
-    my $username = $ENV{LOGNAME} || $ENV{USER} || getpwuid($<);
-
-    # Skip the first line which contains the version header.
-    print scalar <>;
-
-    # The second line contains the start of the infinite array.
-    print scalar <>;
+    sub register_caffeinated {
+	$caffeinated_id = $_[0]->{id};
+	$info{caffeinated_name} = $_[0]->{name};
+	kill USR1 => $i3status;
+    }
 
-    # Read lines forever, ignore a comma at the beginning if it exists.
-    while (my ($statusline) = (<> =~ /^,?(.*)/)) {
-	# If there is a decoding error, just skip this line, to minimise
-	# status bar freezes.  This should be fine here because this filtering
-	# loop is in itself stateless.  It's only if the decoding error
-	# involves newlines in the wrong places, or similar, that this skip
-	# could cause us to produce invalid output.
-        my $blocks = eval { decode_json $statusline } // next;
+    sub clear_caffeinated {
+	undef $caffeinated_id;
+	undef $info{caffeinated_name};
+	kill USR1 => $i3status;
+    }
 
-        unshift @$blocks,
-          {
-            name      => "caffeinated",
-            full_text => "Caffeinated: " . $info{caffeinated_name} }
-          if $info{caffeinated_name};
+    # Determine the initial state -- the WM might just have been reloaded.
 
-        unshift @$blocks,
-          { name => "hostinfo", full_text => $username . "@" . $hostname };
+    my $workspaces = @{ decode_json `$wmipc -t get_workspaces` };
+    wsbuttons($workspaces > 1 ? "yes" : "no");
 
-        print encode_json($blocks) . ",\n";
+    my @trees = decode_json `$wmipc -t get_tree`;
+    while (@trees) {
+	for ((shift @trees)->{nodes}->@*) {
+	    if (grep $_ eq "caffeinated", $_->{marks}->@*) {
+		register_caffeinated($_);
+		last;
+	    } else {
+		unshift @trees, $_;
+	    }
+	}
     }
+
+    # Now loop forever reading events, assuming no exceptions.
+
+    eval {
+	while (my $event = decode_json <$events>) {
+	    if ($event->{change} eq "mark") {
+		if (grep $_ eq "caffeinated", $event->{container}{marks}->@*)
+		{
+		    register_caffeinated($event->{container});
+		} elsif ($caffeinated_id
+		    and $caffeinated_id == $event->{container}{id}) {
+		    clear_caffeinated();
+		}
+	    } elsif ($event->{change} eq "init") {
+		++$workspaces == 2 and wsbuttons("yes");
+	    } elsif ($event->{change} eq "empty") {
+		--$workspaces == 1 and wsbuttons("no");
+		# For simplicity, only fresh-workspace script calls
+		# compact_workspaces atm.  For greater consistency we could
+		# call it here, too, without supplying a leave_gap argument.
+	    }
+	}
+    };
+
+    # Give up if there's a decoding error.  We can't ignore the problem
+    # because we don't want our ideas regarding how many workspaces there are,
+    # and whether anything is caffeinated, to get out of sync.
+    #
+    # The user can use the WM's "reload" command to restart this loop.
+    $@ and wsbuttons("yes"), clear_caffeinated();
 }
 
-my $caffeinated_id;
+$pipe->reader;
+open STDIN, "<&=", $pipe->fileno or die "couldn't reopen STDIN!";
 
-open my $events, "-|",
-  $wmipc, "-t", "subscribe", "-m", '[ "window", "workspace" ]';
+# Following based on Michael Stapelberg's sample i3status-wrapper script.
 
-# Determine the initial state -- the WM might just have been reloaded.
+my $hostname = hostname;
+my $username = $ENV{LOGNAME} || $ENV{USER} || getpwuid($<);
 
-my $workspaces = @{ decode_json `$wmipc -t get_workspaces` };
-wsbuttons($workspaces > 1 ? "yes" : "no");
+# Skip the first line which contains the version header.
+print scalar <>;
 
-my @trees = decode_json `$wmipc -t get_tree`;
-while (@trees) {
-    for ((shift @trees)->{nodes}->@*) {
-	if (grep $_ eq "caffeinated", $_->{marks}->@*) {
-	    register_caffeinated($_);
-	    last;
-	} else {
-	    unshift @trees, $_;
-	}
-    }
-}
+# The second line contains the start of the infinite array.
+print scalar <>;
 
-# Now loop forever reading events, assuming no exceptions.
+# Read lines forever, ignore a comma at the beginning if it exists.
+while (my ($statusline) = (<> =~ /^,?(.*)/)) {
+    # If there is a decoding error, just skip this line, to minimise status
+    # bar freezes.  This should be fine here because this filtering loop is in
+    # itself stateless.  It's only if the decoding error involves newlines in
+    # the wrong places, or similar, that this skip could cause us to produce
+    # invalid output.
+    my $blocks = eval { decode_json $statusline } // next;
 
-eval {
-    while (my $event = decode_json <$events>) {
-	if ($event->{change} eq "mark") {
-	    if (grep $_ eq "caffeinated", $event->{container}{marks}->@*) {
-		register_caffeinated($event->{container});
-	    } elsif ($caffeinated_id
-		and $caffeinated_id == $event->{container}{id}) {
-		clear_caffeinated();
-	    }
-	} elsif ($event->{change} eq "init") {
-	    ++$workspaces == 2 and wsbuttons("yes");
-	} elsif ($event->{change} eq "empty") {
-	    --$workspaces == 1 and wsbuttons("no");
-	    # For simplicity, only fresh-workspace script calls
-	    # compact_workspaces atm.  For greater consistency we could call
-	    # it here, too, without supplying a leave_gap argument.
-	}
-    }
-};
+    unshift @$blocks,
+      {
+	  name      => "caffeinated",
+	  full_text => "Caffeinated: " . $info{caffeinated_name} }
+      if $info{caffeinated_name};
 
-# Here we give up if there's a decoding error.  We can't ignore the problem
-# because we don't want our ideas regarding how many workspaces there are, and
-# whether anything is caffeinated, to get out of sync.
-#
-# The user can use the WM's "reload" command to restart the loop.
-$@ and wsbuttons("yes"), clear_caffeinated();
+    unshift @$blocks,
+      { name => "hostinfo", full_text => $username . "@" . $hostname };
+
+    print encode_json($blocks) . ",\n";
+}
 
 sub wsbuttons {
     return unless $ENV{XDG_CURRENT_DESKTOP} eq "sway";
     wmipc "bar bar-0 workspace_buttons $_[0]";
 }
-
-sub register_caffeinated {
-    $caffeinated_id = $_[0]->{id};
-    $info{caffeinated_name} = $_[0]->{name};
-    kill USR1 => $i3status;
-}
-
-sub clear_caffeinated {
-    undef $caffeinated_id;
-    undef $info{caffeinated_name};
-    kill USR1 => $i3status;
-}