--:Minify:--
local args = {...}
local i = 1
local opt = {}

while i <= #args do
    local a = args[i]
    if a == "-l" then i=i+1; opt.newname = args[i]
    elseif a == "-p" then i=i+1; opt.password = args[i]
    elseif a == "-g" then i=i+1; opt.gid = tonumber(args[i])
    elseif a == "-d" then i=i+1; opt.homedir = args[i]
    elseif a == "-s" then i=i+1; opt.shell = args[i]
    elseif a == "-L" then opt.lock = true
    elseif a == "-U" then opt.unlock = true
    elseif a:sub(1,1) ~= "-" then opt.username = a
    else print("usermod: unknown option: " .. a); syscall.exit(1); return end
    i = i + 1
end

if not opt.username then
    print("Usage: usermod [-l newname] [-p password] [-g gid] [-d homedir] [-s shell] [-L] [-U] <username>")
    syscall.exit(1); return
end

if opt.lock and opt.unlock then
    print("usermod: -L and -U are mutually exclusive")
    syscall.exit(1); return
end

local uid = syscall.getuid(opt.username)
if not uid then
    print("usermod: user '" .. opt.username .. "' does not exist")
    syscall.exit(1); return
end

local function apply(fn, ...)
    local ok, err = fn(...)
    if not ok then print("usermod: " .. tostring(err)); syscall.exit(1) end
end

if opt.newname  then apply(syscall.setusername, uid, opt.newname) end
if opt.password then apply(syscall.setpassword, uid, opt.password) end
if opt.gid      then apply(syscall.setgid,      uid, opt.gid) end
if opt.homedir  then apply(syscall.sethomedir,  uid, opt.homedir) end
if opt.shell    then apply(syscall.setshell,     uid, opt.shell) end
if opt.lock     then apply(syscall.lockuser,     uid) end
if opt.unlock   then apply(syscall.unlockuser,   uid) end

print("usermod: updated user '" .. opt.username .. "'")