--:Minify:--
local name = syscall.getTask(syscall.getpid()).name
local args = {}
local cloptions = { help = false }

for _, v in ipairs({ ... }) do
    if v:sub(1, 2) == "--" then
        local opt = v:sub(3)
        if opt == "help" then
            cloptions.help = true
        else
            print(name .. ": unrecognized option '" .. v .. "'")
            print("try '" .. name .. " --help' for more information.")
            syscall.exit(1); return
        end
    elseif v:sub(1, 1) == "-" then
        print(name .. ": invalid option '" .. v .. "'")
        print("try '" .. name .. " --help' for more information.")
        syscall.exit(1); return
    else
        table.insert(args, v)
    end
end

if cloptions.help then
    print("Usage: " .. name .. " NEWROOT [COMMAND [ARG]...]")
    print("Run COMMAND with root directory set to NEWROOT.")
    print("If COMMAND is omitted, runs the current user's shell.")
    print("")
    print("Requires root (uid 0).")
    return
end

if #args < 1 then
    print(name .. ": missing operand")
    print("try '" .. name .. " --help' for more information.")
    syscall.exit(1); return
end

local euid = syscall.geteuid and syscall.geteuid() or syscall.getuid()
if euid ~= 0 then
    print(name .. ": cannot change root directory: Permission denied")
    syscall.exit(1); return
end

local newRoot = args[1]
if newRoot:sub(1,1) ~= "/" then
    newRoot = syscall.getcwd() .. "/" .. newRoot
end

if not syscall.exists(newRoot) then
    print(name .. ": cannot change root directory to '" .. args[1] .. "': No such file or directory")
    syscall.exit(1); return
end

if syscall.type(newRoot) ~= "directory" then
    print(name .. ": '" .. args[1] .. "': Not a directory")
    syscall.exit(1); return
end

local ok, err = pcall(syscall.chroot, newRoot)
if not ok then
    print(name .. ": cannot change root directory to '" .. args[1] .. "': " .. tostring(err))
    syscall.exit(1); return
end

local shell
if #args >= 2 then
    shell = args[2]
else
    local uid  = syscall.getuid()
    local pwent = syscall.getpasswd(uid)
    shell = (pwent and pwent.shell) or "/bin/hysh"
end

local execArgs = {}
for i = 3, #args do table.insert(execArgs, args[i]) end

local execOk, execErr = pcall(syscall.exec, shell, execArgs)
if not execOk then
    print(name .. ": failed to run command '" .. shell .. "': " .. tostring(execErr))
    syscall.exit(127)
end