refactor: implement fg in lua

exec.go

@@ -17,7 +17,6 @@ import (
 	"hilbish/util"
 
 	rt "github.com/arnodel/golua/runtime"
-	"golang.org/x/sys/unix"
 	"mvdan.cc/sh/v3/shell"
 	//"github.com/yuin/gopher-lua/parse"
 	"mvdan.cc/sh/v3/interp"
@@ -274,25 +273,6 @@ func execHandle(bg bool) interp.ExecHandlerFunc {
 			}
 		}
 
-		// sh interp has "fg" as unimplemented builtin, which panics
-		if args[0] == "fg" {
-			j := jobs.getLatest()
-			if j == nil || j.pid == 0 {
-				return interp.NewExitStatus(1)
-			}
-
-			pgid, _ := syscall.Getpgid(j.pid)
-			hshPgid, _ := syscall.Getpgid(os.Getpid())
-
-			// tcsetpgrp
-			unix.IoctlSetPointerInt(0, unix.TIOCSPGRP, pgid)
-			proc, _ := os.FindProcess(j.pid)
-			proc.Wait()
-			unix.IoctlSetPointerInt(0, unix.TIOCSPGRP, hshPgid)
-
-			return interp.NewExitStatus(0)
-		}
-
 		// If command is defined in Lua then run it
 		luacmdArgs := rt.NewTable()
 		for i, str := range args[1:] {

nature/commands/fg.lua

@@ -0,0 +1,15 @@
+local commander = require 'commander'
+
+commander.register('fg', function()
+	local job = hilbish.jobs.last()
+	if not job then
+		print 'fg: no last job'
+		return 1
+	end
+
+	local err = job.foreground() -- waits for job; blocks
+	if err then
+		print('fg: ' .. err)
+		return 2
+	end
+end)

nature/commands/init.lua

@@ -5,3 +5,4 @@ require 'nature.commands.doc'
 require 'nature.commands.exit'
 require 'nature.commands.guide'
 require 'nature.commands.disown'
+require 'nature.commands.fg'