--:Minify:--
syscall.open("/dev/tty/TTY1","r") --stdin  (Device 0)
syscall.open("/dev/tty/TTY1","w") --stdout (Device 1)
syscall.open("/dev/null","w")     --stderr (device 2)

local success, errorMsg = xpcall(function()

local fs = require("sys.fs")

syscall.devctl(1,"clear")
syscall.devctl(1,"sfgc",1)
syscall.devctl(1,"spos",1,1)
print("HyperionOS hysh Shell")

local userhost = (syscall.getUsername() or "Unknown").."@"..(syscall.getHostname() or "Unknown")
local commandHistory = {}
local terminate = false
syscall.setEnviron("SHELL","rtbash")
syscall.setEnviron("PATH","/bin/")
syscall.chdir("/")
local oldWD = ""

for i = 1, 16 do
    syscall.devctl(1,"sbgc",i); printInline("   ")
end
print("\n")

syscall.sigcatch(function(sig)
    if sig == 1 then terminate = true end
end)

local function abspath(p)
    if not p or p == "" then return syscall.getcwd() end
    if p:sub(1,1) ~= "/" then p = syscall.getcwd().."/"..p end
    local parts = {}
    for seg in p:gmatch("[^/]+") do
        if seg == ".." then if #parts > 0 then table.remove(parts) end
        elseif seg ~= "." then table.insert(parts, seg) end
    end
    return "/"..table.concat(parts, "/")
end

local function basename(p)
    p = p:gsub("/$","")
    return p:match("([^/]+)$") or p
end

local function dirname(p)
    p = p:gsub("/$","")
    local d = p:match("^(.*)/[^/]+$")
    if not d then return "." end
    if d == "" then return "/" end
    return d
end

local function readall(fd)
    local t = {}
    while true do
        local ok, chunk = pcall(syscall.read, fd, 65536)
        if not ok or not chunk or chunk == "" then break end
        t[#t+1] = chunk
    end
    return table.concat(t)
end

local function readfile(path)
    local ok, fd = pcall(syscall.open, path, "r")
    if not ok then return nil, fd end
    local data = readall(fd)
    pcall(syscall.close, fd)
    return data
end

local function writefile(path, data)
    local ok, fd = pcall(syscall.open, path, "w")
    if not ok then return false, fd end
    pcall(syscall.write, fd, data)
    pcall(syscall.close, fd)
    return true
end

local function parseargs(rawargs, flagspec, longflags)
    local opts = {}
    local args = {}
    longflags = longflags or {}
    local i = 1
    while i <= #rawargs do
        local v = rawargs[i]
        if v == "--" then
            for j = i+1, #rawargs do args[#args+1] = rawargs[j] end
            break
        elseif v:sub(1,2) == "--" then
            local lf = v:sub(3)
            if longflags[lf] ~= nil then opts[lf] = true
            else opts["_unknown"] = v end
        elseif v:sub(1,1) == "-" and #v > 1 then
            for k = 2, #v do
                local c = v:sub(k,k)
                if flagspec:find(c, 1, true) then opts[c] = true
                else opts["_unknown"] = "-"..c end
            end
        else
            args[#args+1] = v
        end
        i = i + 1
    end
    return opts, args
end

local function eachline(text, fn)
    local pos = 1
    while pos <= #text do
        local nl = text:find("\n", pos, true)
        if nl then fn(text:sub(pos, nl-1)); pos = nl+1
        else fn(text:sub(pos)); break end
    end
end

local function splitlines(text)
    local lines = {}
    eachline(text, function(l) lines[#lines+1] = l end)
    return lines
end

local function copyfile(src, dst)
    local data, err = readfile(src)
    if not data then return false, err end
    local ok, err2 = writefile(dst, data)
    if not ok then return false, err2 end
    local ok2, stat = pcall(syscall.stat, src)
    if ok2 and stat and stat.perms then pcall(syscall.chmod, dst, stat.perms) end
    return true
end

local function rmtree(path)
    local t = syscall.type(path)
    if t == "directory" then
        local ok, list = pcall(syscall.listdir, path)
        if ok then
            for _, e in ipairs(list) do
                rmtree(path:gsub("/$","").."/"..e)
            end
        end
    end
    if t then pcall(syscall.remove, path) end
end

local function copytree(src, dst)
    pcall(syscall.mkdir, dst)
    local ok, list = pcall(syscall.listdir, src)
    if not ok then return end
    for _, e in ipairs(list) do
        local s = src:gsub("/$","").."/"..e
        local d = dst:gsub("/$","").."/"..e
        local t = syscall.type(s)
        if t == "directory" then copytree(s, d)
        elseif t == "file" then copyfile(s, d)
        elseif t == "symlink" then
            local ok2, tgt = pcall(syscall.readlink, s)
            if ok2 then pcall(syscall.remove, d); pcall(syscall.symlink, tgt, d) end
        end
    end
end

local builtinCmds = {}

builtinCmds.cd = function(path)
    local cwd = syscall.getcwd()
    local dirIn = path or ""
    if dirIn == "-" then
        if oldWD == "" then print("hysh: cd: no previous directory"); return end
        print(oldWD); local tmp = oldWD; oldWD = cwd; syscall.chdir(tmp); return
    end
    local target = abspath(dirIn)
    if target:sub(-1) ~= "/" then target = target.."/" end
    if not fs.isDir(target) then
        print("hysh: cd: "..dirIn..": No such directory"); return
    end
    oldWD = cwd; syscall.chdir(target)
end

builtinCmds.exit = function(code)
    syscall.exit(tonumber(code) or 0)
end

builtinCmds.echo = function(...)
    local args = {...}
    local n = false
    local start = 1
    if args[1] == "-n" then n = true; start = 2 end
    local out = table.concat(args, " ", start)
    if n then printInline(out) else print(out) end
end

builtinCmds.pwd = function()
    print(syscall.getcwd())
end

builtinCmds["true"]  = function() end
builtinCmds["false"] = function() end

builtinCmds.sleep = function(...)
    local args = {...}
    if #args == 0 then print("sleep: missing operand"); return end
    local total = 0
    for _, a in ipairs(args) do
        local n, u = a:match("^([%d%.]+)([smhd]?)$")
        if not n then print("sleep: invalid time '"..a.."'"); return end
        n = tonumber(n)
        if     u == "m" then n = n * 60
        elseif u == "h" then n = n * 3600
        elseif u == "d" then n = n * 86400 end
        total = total + n
    end
    sleep(total)
end

builtinCmds.clear = function()
    syscall.devctl(1,"clear")
    syscall.devctl(1,"sfgc",1)
    syscall.devctl(1,"spos",1,1)
end

builtinCmds.whoami = function()
    print(syscall.getUsername() or "unknown")
end

builtinCmds.hostname = function(...)
    local args = {...}
    if #args == 0 then
        print(syscall.getHostname() or "unknown")
    else
        local ok, err = pcall(syscall.setHostname, args[1])
        if not ok then print("hostname: "..tostring(err)) end
    end
end

builtinCmds.uname = function(...)
    local opts, _ = parseargs({...}, "asnrm")
    local all = opts.a
    local parts = {}
    local results = {}
    for word in string.gmatch(syscall.version(), "%S+") do
        table.insert(results, word)
    end
    if all or opts.s or (not opts.s and not opts.n and not opts.r and not opts.m) then
        parts[#parts+1] = results[1]
    end
    if all or opts.n then parts[#parts+1] = (syscall.getHostname() or "hyperion") end
    if all or opts.r then parts[#parts+1] = results[2] end
    if all or opts.m then parts[#parts+1] = "virtual" end
    print(table.concat(parts, " "))
end

builtinCmds.printenv = function(...)
    local args = {...}
    local vars = {"PATH","HOME","USER","SHELL","TERM","HOSTNAME","PWD","OLDPWD","LANG","TZ","EDITOR"}
    if #args == 0 then
        for _, k in ipairs(vars) do
            local ok, v = pcall(syscall.getEnviron, k)
            if ok and v then print(k.."="..v) end
        end
    else
        for _, k in ipairs(args) do
            local ok, v = pcall(syscall.getEnviron, k)
            if ok and v then print(v) end
        end
    end
end

builtinCmds.env = function(...)
    local args = {...}
    local i = 1
    while i <= #args and args[i]:match("^[%w_]+=") do
        local k, v = args[i]:match("^([^=]+)=(.*)")
        pcall(syscall.setEnviron, k, v)
        i = i + 1
    end
    if i > #args then
        builtinCmds.printenv()
    end
end

builtinCmds.touch = function(...)
    local _, args = parseargs({...}, "amc")
    if #args == 0 then print("touch: missing operand"); return end
    for _, a in ipairs(args) do
        local path = abspath(a)
        if not syscall.exists(path) then
            local ok, fd = pcall(syscall.open, path, "w")
            if ok then pcall(syscall.close, fd)
            else print("touch: cannot create '"..a.."': "..tostring(fd)) end
        end
    end
end

builtinCmds.mkdir = function(...)
    local opts, args = parseargs({...}, "p")
    if #args == 0 then print("mkdir: missing operand"); return end
    for _, a in ipairs(args) do
        local path = abspath(a)
        if path:sub(-1) ~= "/" then path = path.."/" end
        if fs.isDir(path) then
            print("mkdir: cannot create '"..a.."': Directory exists"); return
        end
        local ok, err = pcall(syscall.mkdir, path)
        if not ok then print("mkdir: cannot create '"..a.."': "..tostring(err)) end
    end
end

builtinCmds.rm = function(...)
    local opts, args = parseargs({...}, "rRf")
    if #args == 0 then print("rm: missing operand"); return end
    local recursive = opts.r or opts.R
    for _, a in ipairs(args) do
        local path = abspath(a)
        local t = syscall.type(path)
        if not t then
            if not opts.f then print("rm: cannot remove '"..a.."': No such file or directory") end
        elseif t == "directory" then
            if not recursive then print("rm: cannot remove '"..a.."': Is a directory")
            else rmtree(path) end
        else
            local ok, err = pcall(syscall.remove, path)
            if not ok then print("rm: cannot remove '"..a.."': "..tostring(err)) end
        end
    end
end

builtinCmds.cp = function(...)
    local opts, args = parseargs({...}, "rRp")
    if #args < 2 then print("cp: missing operand"); return end
    local recursive = opts.r or opts.R
    local dst = abspath(args[#args])
    local dstIsDir = syscall.type(dst) == "directory"
    if #args > 2 and not dstIsDir then
        print("cp: target '"..args[#args].."' is not a directory"); return
    end
    for i = 1, #args-1 do
        local src = abspath(args[i])
        local t = syscall.type(src)
        if not t then
            print("cp: '"..args[i].."': No such file or directory")
        elseif t == "directory" then
            if not recursive then print("cp: omitting directory '"..args[i].."'")
            else copytree(src, dstIsDir and (dst:gsub("/$","").."/"..basename(args[i])) or dst) end
        else
            local d = dstIsDir and (dst:gsub("/$","").."/"..basename(args[i])) or dst
            local ok, err = copyfile(src, d)
            if not ok then print("cp: '"..args[i].."': "..tostring(err)) end
        end
    end
end

builtinCmds.mv = function(...)
    local opts, args = parseargs({...}, "f")
    if #args < 2 then print("mv: missing operand"); return end
    local dst = abspath(args[#args])
    local dstIsDir = syscall.type(dst) == "directory"
    if #args > 2 and not dstIsDir then
        print("mv: target '"..args[#args].."' is not a directory"); return
    end
    for i = 1, #args-1 do
        local src = abspath(args[i])
        local t = syscall.type(src)
        if not t then
            print("mv: '"..args[i].."': No such file or directory")
        else
            local d = dstIsDir and (dst:gsub("/$","").."/"..basename(args[i])) or dst
            if t == "directory" then
                copytree(src, d); rmtree(src)
            else
                local ok, err = copyfile(src, d)
                if ok then pcall(syscall.remove, src)
                else print("mv: '"..args[i].."': "..tostring(err)) end
            end
        end
    end
end

builtinCmds.cat = function(...)
    local args = {...}
    if #args == 0 then
        while true do
            local ok, chunk = pcall(syscall.read, 0, 4096)
            if not ok or not chunk or chunk == "" then break end
            printInline(chunk)
        end
        print("")
        return
    end
    for _, a in ipairs(args) do
        local path = abspath(a)
        if not syscall.exists(path) then
            print("cat: "..a..": No such file or directory")
        else
            local ok, fd = pcall(syscall.open, path, "r")
            if not ok then print("cat: "..a..": "..tostring(fd))
            else
                while true do
                    local ok2, chunk = pcall(syscall.read, fd, 65536)
                    if not ok2 or not chunk or chunk == "" then break end
                    printInline(chunk)
                end
                pcall(syscall.close, fd)
            end
        end
    end
end

builtinCmds.head = function(...)
    local raw = {...}
    local n = 10
    local files = {}
    local i = 1
    while i <= #raw do
        local v = raw[i]
        if v == "-n" then i=i+1; n=tonumber(raw[i]) or 10
        elseif v:match("^%-n%d+$") then n=tonumber(v:sub(3))
        elseif v:match("^%-%d+$") then n=tonumber(v:sub(2))
        elseif v:sub(1,1) ~= "-" or v == "-" then files[#files+1] = v
        end
        i=i+1
    end
    local multi = #files > 1
    local function dohead(text, label)
        if multi then
            syscall.devctl(1,"sfgc",4); print("==> "..label.." <=="); syscall.devctl(1,"sfgc",1)
        end
        local count = 0
        for line in (text.."\n"):gmatch("([^\n]*)\n") do
            if count >= n then break end
            print(line); count = count+1
        end
    end
    if #files == 0 then
        dohead(readall(0), "stdin")
    else
        for _, a in ipairs(files) do
            if a == "-" then dohead(readall(0), "stdin")
            else
                local data, err = readfile(abspath(a))
                if not data then print("head: "..a..": "..tostring(err))
                else dohead(data, a) end
            end
        end
    end
end

builtinCmds.tail = function(...)
    local raw = {...}
    local n = 10
    local files = {}
    local i = 1
    while i <= #raw do
        local v = raw[i]
        if v == "-n" then i=i+1; n=tonumber(raw[i]) or 10
        elseif v:match("^%-n%d+$") then n=tonumber(v:sub(3))
        elseif v:match("^%-%d+$") then n=tonumber(v:sub(2))
        elseif v:sub(1,1) ~= "-" or v == "-" then files[#files+1] = v
        end
        i=i+1
    end
    local multi = #files > 1
    local function dotail(text, label)
        if multi then
            syscall.devctl(1,"sfgc",4); print("==> "..label.." <=="); syscall.devctl(1,"sfgc",1)
        end
        local lines = splitlines(text)
        local start = math.max(1, #lines - n + 1)
        for j = start, #lines do print(lines[j]) end
    end
    if #files == 0 then dotail(readall(0), "stdin")
    else
        for _, a in ipairs(files) do
            if a == "-" then dotail(readall(0), "stdin")
            else
                local data, err = readfile(abspath(a))
                if not data then print("tail: "..a..": "..tostring(err))
                else dotail(data, a) end
            end
        end
    end
end

builtinCmds.wc = function(...)
    local opts, args = parseargs({...}, "lwc")
    local showAll = not opts.l and not opts.w and not opts.c
    if showAll then opts.l=true; opts.w=true; opts.c=true end
    local function count(text)
        local l,w,b = 0,0,#text
        for _ in text:gmatch("\n") do l=l+1 end
        for _ in text:gmatch("%S+") do w=w+1 end
        return l,w,b
    end
    local function fmt(l,w,c,lbl)
        local p={}
        if opts.l then p[#p+1]=string.format("%7d",l) end
        if opts.w then p[#p+1]=string.format("%7d",w) end
        if opts.c then p[#p+1]=string.format("%7d",c) end
        if lbl then p[#p+1]=" "..lbl end
        print(table.concat(p))
    end
    local tl,tw,tc = 0,0,0
    if #args == 0 then
        local l,w,c = count(readall(0)); fmt(l,w,c)
    else
        for _, a in ipairs(args) do
            local data, err = readfile(abspath(a))
            if not data then print("wc: "..a..": "..tostring(err))
            else
                local l,w,c = count(data); fmt(l,w,c,a)
                tl=tl+l; tw=tw+w; tc=tc+c
            end
        end
        if #args > 1 then fmt(tl,tw,tc,"total") end
    end
end

builtinCmds.grep = function(...)
    local opts, args = parseargs({...}, "ivnlcrR", {["ignore-case"]=true,["invert-match"]=true})
    if #args == 0 then print("grep: missing pattern"); return end
    local pat = args[1]
    if opts.i or opts["ignore-case"] then pat = pat:lower() end
    local recursive = opts.r or opts.R
    local found = false

    local function greptext(text, label, showlabel)
        local count = 0
        local linenum = 0
        local hasMatch = false
        eachline(text, function(line)
            linenum = linenum+1
            local test = (opts.i or opts["ignore-case"]) and line:lower() or line
            local m = (test:find(pat) ~= nil)
            if opts.v or opts["invert-match"] then m = not m end
            if m then
                count=count+1; hasMatch=true; found=true
                if not opts.l and not opts.c then
                    local out = ""
                    if showlabel then out=out..label..":" end
                    if opts.n then out=out..linenum..":" end
                    print(out..line)
                end
            end
        end)
        if opts.l and hasMatch then print(label) end
        if opts.c then
            print((showlabel and label..":" or "")..count)
        end
    end

    local function grepfile(path, label, showlabel)
        local data, err = readfile(path)
        if not data then print("grep: "..label..": "..tostring(err)); return end
        greptext(data, label, showlabel)
    end

    local function grepdir(dir, prefix)
        local ok, list = pcall(syscall.listdir, dir)
        if not ok then return end
        for _, e in ipairs(list) do
            local fp = dir:gsub("/$","").."/"..e
            local lbl = (prefix ~= "" and prefix.."/" or "")..e
            local t = syscall.type(fp)
            if t == "directory" then grepdir(fp, lbl)
            elseif t == "file" then grepfile(fp, lbl, true) end
        end
    end

    if #args == 1 then
        greptext(readall(0), "(stdin)", false)
    else
        local showlabel = #args > 2 or recursive
        for i = 2, #args do
            local path = abspath(args[i])
            local t = syscall.type(path)
            if t == "directory" then
                if recursive then grepdir(path, args[i])
                else print("grep: "..args[i]..": Is a directory") end
            elseif t then
                grepfile(path, args[i], showlabel)
            else
                print("grep: "..args[i]..": No such file or directory")
            end
        end
    end
end

builtinCmds.sort = function(...)
    local opts, args = parseargs({...}, "rnu")
    local lines = {}
    local function addlines(text)
        local ls = splitlines(text)
        for _, l in ipairs(ls) do lines[#lines+1] = l end
    end
    if #args == 0 then addlines(readall(0))
    else
        for _, a in ipairs(args) do
            local data, err = readfile(abspath(a))
            if not data then print("sort: "..a..": "..tostring(err))
            else addlines(data) end
        end
    end
    table.sort(lines, function(a,b)
        if opts.n then
            local na = tonumber(a:match("^%-?%d+%.?%d*")) or 0
            local nb = tonumber(b:match("^%-?%d+%.?%d*")) or 0
            return opts.r and na > nb or na < nb
        end
        return opts.r and a > b or a < b
    end)
    local prev = nil
    for _, l in ipairs(lines) do
        if not opts.u or l ~= prev then print(l); prev = l end
    end
end

builtinCmds.uniq = function(...)
    local opts, args = parseargs({...}, "cdui")
    local text
    if args[1] then
        local data, err = readfile(abspath(args[1]))
        if not data then print("uniq: "..args[1]..": "..tostring(err)); return end
        text = data
    else text = readall(0) end

    local prev, prevCount = nil, 0
    local out = {}
    local function emit(line, count)
        if opts.d and count == 1 then return end
        if opts.u and count > 1  then return end
        out[#out+1] = opts.c and string.format("%7d %s", count, line) or line
    end
    eachline(text, function(line)
        local cmp = opts.i and line:lower() or line
        local cprev = opts.i and (prev and prev:lower()) or prev
        if cmp == cprev then prevCount = prevCount+1
        else
            if prev ~= nil then emit(prev, prevCount) end
            prev = line; prevCount = 1
        end
    end)
    if prev ~= nil then emit(prev, prevCount) end

    if args[2] then
        local ok, err = writefile(abspath(args[2]), table.concat(out, "\n").."\n")
        if not ok then print("uniq: "..args[2]..": "..tostring(err)) end
    else
        for _, l in ipairs(out) do print(l) end
    end
end

builtinCmds.tee = function(...)
    local opts, args = parseargs({...}, "a")
    local mode = opts.a and "a" or "w"
    local fds = {}
    for _, a in ipairs(args) do
        local ok, fd = pcall(syscall.open, abspath(a), mode)
        if not ok then print("tee: "..a..": "..tostring(fd))
        else fds[#fds+1] = fd end
    end
    while true do
        local ok, chunk = pcall(syscall.read, 0, 4096)
        if not ok or not chunk or chunk == "" then break end
        pcall(syscall.write, 1, chunk)
        for _, fd in ipairs(fds) do pcall(syscall.write, fd, chunk) end
    end
    for _, fd in ipairs(fds) do pcall(syscall.close, fd) end
end

builtinCmds.find = function(...)
    local raw = {...}
    local roots, filters = {}, {}
    local maxdepth, mindepth = nil, 0
    local i = 1
    while i <= #raw and raw[i]:sub(1,1) ~= "-" do
        roots[#roots+1] = raw[i]; i=i+1
    end
    if #roots == 0 then roots = {"."} end
    while i <= #raw do
        local tok = raw[i]
        if tok == "-name" then
            i=i+1
            local pat = "^"..(raw[i] or ""):gsub("([%.%+%-%^%$%(%)%[%]%%])","%%%1"):gsub("%*",".*"):gsub("%?",".").. "$"
            filters[#filters+1] = function(_, e, _2, _3) return e:match(pat) ~= nil end
        elseif tok == "-type" then
            i=i+1; local ft=raw[i] or ""
            filters[#filters+1] = function(_, _, t, _2)
                if ft=="f" then return t=="file"
                elseif ft=="d" then return t=="directory"
                elseif ft=="l" then return t=="symlink" end; return true
            end
        elseif tok == "-maxdepth" then i=i+1; maxdepth=tonumber(raw[i]) or 0
        elseif tok == "-mindepth" then i=i+1; mindepth=tonumber(raw[i]) or 0
        elseif tok == "-empty" then
            filters[#filters+1] = function(path, _, t, _2)
                if t=="file" then local ok,s=pcall(syscall.stat,path); return ok and s and (s.size or 0)==0
                elseif t=="directory" then local ok,l=pcall(syscall.listdir,path); return ok and l and #l==0 end
                return false
            end
        end
        i=i+1
    end
    local function match(path, e, t, depth)
        for _, f in ipairs(filters) do if not f(path,e,t,depth) then return false end end
        return true
    end
    local function walk(path, disp, depth)
        local t = syscall.type(path)
        if not t then return end
        local e = path:match("([^/]+)/?$") or path
        if depth >= mindepth and match(path,e,t,depth) then print(disp) end
        if t=="directory" and (maxdepth==nil or depth<maxdepth) then
            local ok,list = pcall(syscall.listdir, path)
            if ok then
                table.sort(list)
                for _, child in ipairs(list) do
                    walk(path:gsub("/$","").."/"..child, disp:gsub("/$","").."/"..child, depth+1)
                end
            end
        end
    end
    local cwd = syscall.getcwd()
    for _, r in ipairs(roots) do
        local abs = (r == ".") and cwd or abspath(r)
        walk(abs, r, 0)
    end
end

builtinCmds.stat = function(...)
    local _, args = parseargs({...}, "")
    if #args == 0 then print("stat: missing operand"); return end
    local function permstr(p)
        local function b(n) return math.floor(p/(2^n))%2==1 end
        return (b(5) and"r"or"-")..(b(4) and"w"or"-")..(b(9) and"x"or"-")..
               (b(3) and"r"or"-")..(b(2) and"w"or"-")..(b(8) and"x"or"-")..
               (b(1) and"r"or"-")..(b(0) and"w"or"-")..(b(7) and"x"or"-")
    end
    local function octperm(p)
        local function b(n) return math.floor(p/(2^n))%2 end
        local o = b(6)*4096+b(5)*256+b(4)*128+b(9)*64+b(3)*32+b(2)*16+b(8)*8+b(1)*4+b(0)*2+b(7)*1
        return string.format("%04o",o)
    end
    for _, a in ipairs(args) do
        local path = abspath(a)
        if not syscall.exists(path) then
            print("stat: '"..a.."': No such file or directory")
        else
            local t = syscall.type(path)
            local ok, s = pcall(syscall.stat, path)
            s = ok and s or {}
            local tc = t=="directory" and "d" or (t=="symlink" and "l" or "-")
            print("  File: "..a)
            print("  Size: "..tostring(s.size or 0).."  Type: "..(t or "?"))
            print(" Owner: "..tostring(s.owner or 0).."  Group: "..tostring(s.group or 0))
            print("Access: ("..octperm(s.perms or 0).."/"..tc..permstr(s.perms or 0)..")")
            if t == "symlink" then
                local ok2, tgt = pcall(syscall.readlink, path)
                if ok2 then print("  Link: "..tgt) end
            end
            print("")
        end
    end
end

builtinCmds.basename = function(...)
    local args = {...}
    if #args == 0 then print("basename: missing operand"); return end
    local p = args[1]
    while #p > 1 and p:sub(-1)=="/" do p=p:sub(1,-2) end
    local b = p:match("([^/]+)$") or p
    if args[2] and b:sub(-#args[2]) == args[2] then b = b:sub(1, #b-#args[2]) end
    print(b)
end

builtinCmds.dirname = function(...)
    local args = {...}
    if #args == 0 then print("dirname: missing operand"); return end
    for _, p in ipairs(args) do
        while #p > 1 and p:sub(-1)=="/" do p=p:sub(1,-2) end
        local d = p:match("^(.*)/[^/]+$")
        if not d then print(".")
        elseif d == "" then print("/")
        else print(d) end
    end
end

builtinCmds.df = function(...)
    local opts, _ = parseargs({...}, "h")
    local function hfmt(n)
        local u={"K","M","G","T"}; local i=0
        while n>=1024 and i<#u do n=n/1024; i=i+1 end
        if i==0 then return tostring(math.floor(n)) end
        if n<10 then return string.format("%.1f%s",n,u[i]) end
        return math.floor(n)..u[i]
    end
    local function fmt(n) return opts.h and hfmt(n) or tostring(n) end
    print(string.format("%-20s %10s %10s %10s %6s %-s","Filesystem","Size","Used","Avail","Use%","Mounted on"))
    local mounts = {{"$","/"}, {"devfs0000","/dev/"}, {"tmpfs0000","/tmp/"}}
    for _, m in ipairs(mounts) do
        local id, mp = m[1], m[2]
        print(string.format("%-20s %10s %10s %10s %6s %-s", id, "?", "?", "?", "?%", mp))
    end
end

local function getUserInput()
    syscall.devctl(1,"sfgc",3)
    syscall.write(1, userhost)
    syscall.devctl(1,"sfgc",1)
    syscall.write(1, ":")
    syscall.devctl(1,"sfgc",10)
    syscall.write(1, syscall.getcwd())
    syscall.devctl(1,"sfgc",1)
    syscall.write(1, "$ ")
    local curOffsetStr = syscall.devctl(1, "gpos")
    local curOffsetX = tonumber(curOffsetStr:sub(1, curOffsetStr:find(";")-1))
    local curOffsetY = tonumber(curOffsetStr:sub(curOffsetStr:find(";")+1))

    local input = ""
    local blinkState = false
    local cursorPos = 1
    local history = 0
    local dirty = true

    local function redraw()
        syscall.devctl(1,"spos",curOffsetX,curOffsetY)
        syscall.write(1, string.sub(input, 1, cursorPos-1))
        if blinkState then
            syscall.devctl(1,"sfgc",16); syscall.devctl(1,"sbgc",1)
        end
        if cursorPos > #input then
            syscall.write(1, " ")
        else
            syscall.write(1, string.sub(input, cursorPos, cursorPos))
        end
        syscall.devctl(1,"sfgc",1); syscall.devctl(1,"sbgc",16)
        syscall.write(1, string.sub(input, cursorPos+1) .. " ")
    end

    while true do
        local key = syscall.read(0)
        if key and key ~= "" then
            if     key=="\19" then if cursorPos>1       then cursorPos=cursorPos-1;dirty=true end
            elseif key=="\20" then if cursorPos<=#input then cursorPos=cursorPos+1;dirty=true end
            elseif key=="\17" then
                if history<#commandHistory then
                    history=history+1
                    input=commandHistory[#commandHistory-history+1]
                    cursorPos=#input+1;dirty=true
                end
            elseif key=="\18" then
                if history>1 then
                    history=history-1
                    input=commandHistory[#commandHistory-history+1]
                    cursorPos=#input+1;dirty=true
                elseif history==1 then
                    history=0;input="";cursorPos=1;dirty=true
                end
            elseif key=="\b" then
                if cursorPos>1 then
                    input=string.sub(input,1,cursorPos-2)..string.sub(input,cursorPos)
                    cursorPos=cursorPos-1;dirty=true
                end
            elseif key=="\n" then
                syscall.devctl(1,"sfgc",1);syscall.devctl(1,"sbgc",16)
                syscall.devctl(1,"spos",curOffsetX,curOffsetY)
                syscall.write(1, input.." \n")
                return input
            else
                input=string.sub(input,1,cursorPos-1)..key..string.sub(input,cursorPos)
                cursorPos=cursorPos+1;dirty=true
            end
        end
        local curBlink = ((math.floor(syscall.getUptime()/500)%2)==0)
        if curBlink~=blinkState then blinkState=curBlink;dirty=true end
        if dirty then redraw();dirty=false end
    end
end

local function printError(progName, msg)
    syscall.devctl(1,"sfgc",2)
    local s = tostring(msg)
    local line, rest = s:match("%]:(%d+): (.+)$")
    if not line then line, rest = s:match(":(%d+): (.+)$") end
    if line then
        printInline(progName..": error on line "..line..": "); print(rest)
    else
        print(progName..": "..s)
    end
    syscall.devctl(1,"sfgc",1)
end

local function runCommand(command)
    do
        local func = load("return "..command, "@equation", "t", {})
        if func then
            local ok, result = pcall(func)
            if ok and type(result)=="number" then print(result); return end
        end
    end

    terminate = false
    local args = string.split(command, " ")
    for i = #args, 1, -1 do
        if args[i] == "" then table.remove(args, i) end
    end
    if #args == 0 then return end

    if builtinCmds[args[1]] then
        local ok, err = pcall(builtinCmds[args[1]], table.unpack(args, 2))
        if not ok then printError(args[1], err) end
        return
    end

    local cmdPath = ""
    if string.find(args[1], "/") then
        local candidate = args[1]
        if candidate:sub(1,1) ~= "/" then candidate = syscall.getcwd().."/"..candidate end
        if fs.exists(candidate) then cmdPath = candidate end
    else
        local paths = string.split(syscall.getEnviron("PATH"), ":")
        for _, p in pairs(paths) do
            if fs.exists(p..args[1]) then cmdPath = p..args[1]; break end
        end
        if cmdPath == "" then
            local cwd = syscall.getcwd()
            local candidate = cwd..(cwd:sub(-1)=="/" and "" or "/")..args[1]
            if fs.exists(candidate) then cmdPath = candidate end
        end
    end

    if cmdPath == "" then print(args[1]..": Command not found"); return end

    local progName = cmdPath:match("([^/]+)$") or args[1]

    local xok, xerr = pcall(syscall.access, cmdPath, "x")
    if not xok then
        syscall.devctl(1,"sfgc",2); print(progName..": Permission denied"); syscall.devctl(1,"sfgc",1)
        return
    end

    local text = fs.readAllText(cmdPath)
    local program, err = load(text, progName)
    if not program then
        syscall.devctl(1,"sfgc",2)
        local line, rest = tostring(err):match(":(%d+): (.+)$")
        if line then printInline(progName..": load error on line "..line..": "); print(rest)
        else print(progName..": load error: "..tostring(err)) end
        syscall.devctl(1,"sfgc",1); return
    end

    local proc = syscall.spawn(function(...)
        syscall.open("/dev/tty/TTY1","r")
        syscall.open("/dev/tty/TTY1","w")
        syscall.open("/dev/null","w")
        local ok2, msg = pcall(program, ...)
        if not ok2 then printError(progName, msg) end
    end, progName, nil, {table.unpack(args, 2)})

    while true do
        local exited, code = syscall.collect(proc)
        if exited then
            if code then print("\nTask exited with code:\n"..tostring(code)) end
            return
        end
        if terminate then
            local ok2 = syscall.kill(proc)
            if ok2 then
                syscall.devctl(1,"sbgc",16); syscall.devctl(1,"sfgc",2)
                print("\nProgram Terminated."); syscall.devctl(1,"sfgc",1)
            end
            terminate = false; break
        end
        sleep(0.05)
    end
end

while true do
    local command = getUserInput()
    if command ~= "" then
        if command ~= commandHistory[#commandHistory] then
            table.insert(commandHistory, command)
        end
        runCommand(command)
    end
end

end, debug.traceback)

if not success then
    syscall.log("Error running shell: "..errorMsg, "ERROR")
    syscall.devctl(1,"sfgc",2)
    syscall.devctl(1,"sbgc",16)
    print()
    print("Error running shell: ")
    print(errorMsg)
end