diff --git a/clite/commands.js b/clite/commands.js
index 1e1de00..fb847af 100644
--- a/clite/commands.js
+++ b/clite/commands.js
@@ -668,6 +668,311 @@ Options:
 	return 0;
 });
 
+clite.commands.load('chmod',function(args,env,io) {
+	var short = '';
+	var file = null;
+	var stdlib = io.include('stdlib');
+	var stdio = io.include('stdio');
+	var clite = io.include('clite');
+	var recurse = false;
+	var modmask = null;
+	function help() {
+		stdio.printf(`
+chmod - change file mode bits
+Usage: chmod [OPTION] <MODE> <FILE>
+
+Options:
+-?	Print this help information
+		`);
+	}
+
+	function getModMask(str) {
+		var parts = str.split(',');
+		var modmask = ['???','???','???'];
+		if (parts.length == 1 && (str.length == 3 || str.length == 4)) {
+			var iv = parseInt(str,10);
+			if (iv > 0) {
+				if (str.length == 4)
+					str = str.substring(1);
+				for (var i=0; i<str.length; i++) {
+					switch(str[i]) {
+					case '0':
+						modmask[i] = '---';
+						break;
+					case '1':
+						modmask[i] = '--x';
+						break;
+					case '2':
+						modmask[i] = '-w-';
+						break;
+					case '3':
+						modmask[i] = '-wx';
+						break;
+					case '4':
+						modmask[i] = 'r--';
+						break;
+					case '5':
+						modmask[i] = 'r-x';
+						break;
+					case '6':
+						modmask[i] = 'rw-';
+						break;
+					case '7':
+						modmask[i] = 'rwx';
+						break;
+					}
+				}
+				return modmask.join('');
+			}
+		}
+		parts.forEach(function(p) { // [who]op[perm]
+			var u = false;
+			var g = false;
+			var o = false;
+			var op = null;
+			var s = 0;
+			for (var i=0; i<p.length; i++) {
+				if (s == 0) {
+					switch (p[i]) {
+					case 'u':
+						u = true;
+						break;
+					case 'g':
+						g = true;
+						break;
+					case 'o':
+						o = true;
+						break;
+					case 'a':
+						u = true;
+						g = true;
+						o = true;
+						break;
+					case '=':
+					case '+':
+					case '-':
+						op = p[i];
+						s = 1;
+						if (!u && !g && !o) {
+							u = true;
+							g = true;
+							o = true;
+						}
+						if (op == '=') {
+							if (u)
+								modmask[0] = '---';
+							if (g)
+								modmask[1] = '---';
+							if (o)
+								modmask[2] = '---';
+						}
+						break;
+					}
+				}else if (s == 1) {
+					switch (p[i]) {
+					case 'r':
+						if (u) {
+							if (op == '=' || op == '+') {
+								modmask[0] = 'r'+modmask[0][1]+modmask[0][2];
+							}else if (op = '-') {
+								modmask[0] = '-'+modmask[0][1]+modmask[0][2];
+							}
+						}
+						if (g) {
+							if (op == '=' || op == '+') {
+								modmask[1] = 'r'+modmask[1][1]+modmask[1][2];
+							}else if (op = '-') {
+								modmask[1] = '-'+modmask[1][1]+modmask[1][2];
+							}
+						}
+						if (o) {
+							if (op == '=' || op == '+') {
+								modmask[2] = 'r'+modmask[2][1]+modmask[2][2];
+							}else if (op = '-') {
+								modmask[2] = '-'+modmask[2][1]+modmask[2][2];
+							}
+						}
+						break;
+					case 'w':
+						if (u) {
+							if (op == '=' || op == '+') {
+								modmask[0] = modmask[0][0]+'w'+modmask[0][2];
+							}else if (op = '-') {
+								modmask[0] = modmask[0][0]+'-'+modmask[0][2];
+							}
+						}
+						if (g) {
+							if (op == '=' || op == '+') {
+								modmask[1] = modmask[1][0]+'w'+modmask[1][2];
+							}else if (op = '-') {
+								modmask[1] = modmask[1][0]+'-'+modmask[1][2];
+							}
+						}
+						if (o) {
+							if (op == '=' || op == '+') {
+								modmask[2] = modmask[2][0]+'w'+modmask[2][2];
+							}else if (op = '-') {
+								modmask[2] = modmask[2][0]+'-'+modmask[2][2];
+							}
+						}
+						break;
+					case 'x':
+						if (u) {
+							if (op == '=' || op == '+') {
+								modmask[0] = modmask[0][0]+modmask[0][1]+'x';
+							}else if (op = '-') {
+								modmask[0] = modmask[0][1]+modmask[0][1]+'-';
+							}
+						}
+						if (g) {
+							if (op == '=' || op == '+') {
+								modmask[1] = modmask[1][0]+modmask[1][1]+'x';
+							}else if (op = '-') {
+								modmask[1] = modmask[1][0]+modmask[1][1]+'-';
+							}
+						}
+						if (o) {
+							if (op == '=' || op == '+') {
+								modmask[2] = modmask[2][0]+modmask[2][1]+'x';
+							}else if (op = '-') {
+								modmask[2] = modmask[2][0]+modmask[2][1]+'-';
+							}
+						}
+						break;
+					case 'X':
+						if (u) {
+							if (op == '=' || op == '+') {
+								modmask[0] = modmask[0][0]+modmask[0][1]+'X';
+							}else if (op = '-') {
+								modmask[0] = modmask[0][1]+modmask[0][1]+'Y';
+							}
+						}
+						if (g) {
+							if (op == '=' || op == '+') {
+								modmask[1] = modmask[1][0]+modmask[1][1]+'X';
+							}else if (op = '-') {
+								modmask[1] = modmask[1][0]+modmask[1][1]+'Y';
+							}
+						}
+						if (o) {
+							if (op == '=' || op == '+') {
+								modmask[2] = modmask[2][0]+modmask[2][1]+'X';
+							}else if (op = '-') {
+								modmask[2] = modmask[2][0]+modmask[2][1]+'Y';
+							}
+						}
+						break;
+					case 'u':
+						if (g)
+							modmask[1] = modmask[0];
+						if (o)
+							modmask[2] = modmask[0];
+						s = 0;
+						break;
+					case 'g':
+						if (u)
+							modmask[0] = modmask[1];
+						if (o)
+							modmask[2] = modmask[1];
+						s = 0;
+						break;
+					case 'o':
+						if (u)
+							modmask[0] = modmask[2];
+						if (g)
+							modmask[1] = modmask[2];
+						s = 0;
+						break;
+					}
+				}else{ // ?
+					return;
+				}
+			}
+		});
+
+		return modmask.join('');
+	}
+
+	function getPerms(str,isdir) {
+		var n = str.substring(1);
+		for (var i=0; i<9; i++) {
+			if (modmask[i] == '?')
+				continue;
+			if (modmask[i] == n[i])
+				continue;
+			if (modmask[i] == 'X') {
+				if (isdir)
+					n = n.substring(0,i)+'x'+n.substring(i+1);
+			}else if (modmask[i] == 'Y') {
+				if (isdir)
+					n = n.substring(0,i)+'-'+n.substring(i+1);
+			}else{
+				n = n.substring(0,i)+modmask[i]+n.substring(i+1);
+			}
+		}
+
+		return n;
+	}
+
+	if (args.length == 3) { // name mode file
+		modmask = getModMask(args[1]);
+		short = args[2];
+		file = clite.resolvePath(short);
+	}else if (args.length == 4) { // name option mode file
+		if (args[1][0] != '-') {
+			stdio.write(io.stderr,'invalid arguments\n');
+			return 1;
+		}
+		for (var j=1; j<args[1].length; j++) {
+			switch (args[1][j]) {
+			case 'R':
+				recurse = true;
+				break;
+			case '?':
+				help();
+				return 0;
+				break;
+			default:
+				stdio.fprintf(io.stderr,'unknown argument: -%c\n',args[i][j]);
+			}
+		}
+		modmask = getModMask(args[2]);
+		short = args[3];
+		file = clite.resolvePath(short);
+	}else if (args.length == 2 && args[1] == '-?') {
+		help();
+		return 0;
+	}else{
+		stdio.write(io.stderr,'invalid arguments\n');
+		return 1;
+	}
+
+	if (modmask == null || modmask == '?????????') {
+		stdio.write(io.stderr,'invalid mode\n');
+		return 1;
+	}
+
+	if (file == null) {
+		stdio.write(io.stderr,'no file specified\n');
+		return 1;
+	}
+
+	var st = stdio.stat(file);
+	if (!st) {
+		stdio.fprintf(io.stderr,'cannot open file: %s\n',short);
+		return 1;
+	}
+
+	var perms = getPerms(st.perms,(st.type == stdio.types.FT_DIR));
+
+	if (!stdio.chmod(file,perms)) {
+		stdio.fprintf(io.stderr,'cannot write file: %s\n',short);
+		return 1;
+	}
+
+	return 0;
+});
+
 clite.commands.load('file',function(args,env,io) {
 	var short = '';
 	var file = null;
@@ -693,14 +998,14 @@ Options:
 					return 0;
 					break;
 				default:
-					stdio.write(io.stderr,'unknown argument: -'+args[i][j]);
+					stdio.fprintf(io.stderr,'unknown argument: -%c\n',args[i][j]);
 				}
 			}
 		}else if (file == null) {
 			short = args[i];
 			file = clite.resolvePath(args[i],false);
 		}else{
-			stdio.write(io.stderr,'unknown argument: '+args[i]);
+			stdio.fprintf(io.stderr,'unknown argument: %s\n',args[i]);
 		}
 	}
 
@@ -709,18 +1014,12 @@ Options:
 		return 1;
 	}
 
-	var fd = stdio.open(file,false);
-	if (!fd) {
-		stdio.write(io.stderr,'cannot open file: '+file);
-		return 1;
-	}
-
-	var st = stdio.fstat(fd);
-	stdio.close(fd);
+	var st = stdio.stat(file);
 
 	var txt = short+': ';
 	if (!st) {
-		txt += 'Unknown';
+		stdio.fprintf(io.stderr,'cannot open file: %s',file);
+		return 1;
 	}else{
 		switch (st.type) {
 		case stdio.types.FT_TEXT: