diff --git a/Cargo.toml b/Cargo.toml
index 9f38498..7969df8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "quickmath"
-version = "0.2.4"
+version = "0.3.1"
 edition = "2021"
 authors = [ "Valerie Wolfe <sleeplessval@gmail.com>" ]
 description = "A quick command-line math evaluator."
@@ -14,6 +14,8 @@ path = "src/main.rs"
 
 [dependencies]
 evalexpr = "11.0.0"
+pico-args = "0.5.0"
+rustyline = "14.0.0"
 termion = "1.5.6"
 
 [profile.release]
diff --git a/src/global.rs b/src/context/global.rs
similarity index 100%
rename from src/global.rs
rename to src/context/global.rs
diff --git a/src/context/helper.rs b/src/context/helper.rs
new file mode 100644
index 0000000..4bfaa85
--- /dev/null
+++ b/src/context/helper.rs
@@ -0,0 +1,140 @@
+use evalexpr::{
+	Value,
+
+	EvalexprError
+};
+
+use crate::util;
+
+pub type EvalResult = Result<Value, EvalexprError>;
+
+
+//	Mathematics
+pub fn cosine(arg: &Value) -> EvalResult {
+	Ok(
+		if		let Value::Float(float)	= arg { float.clone() }
+		else if	let Value::Int(int)		= arg { int.clone() as f64 }
+		else { return Err(EvalexprError::expected_number(arg.clone())) }
+		.cos().into()
+	)
+}
+
+pub fn fix(arg: &Value) -> EvalResult {
+	if let Value::Tuple(args) = arg {
+		let len = args.len();
+		if len == 2 {
+			let value =
+				if let Value::Float(float) = args[0] { float.clone() }
+				else { return Err(EvalexprError::expected_float(args[0].clone())); };
+
+			let operand = 10u64.pow(
+				if let Value::Int(int) = args[1] { int.clone() }
+				else { return Err(EvalexprError::expected_int(args[1].clone())); }
+				as u32
+			) as f64;
+
+			Ok( ((value * operand).round() / operand).into() )
+		} else { Err(EvalexprError::wrong_function_argument_amount(len, 2)) }
+	} else { Err(EvalexprError::wrong_function_argument_amount(1, 2)) }
+}
+
+pub fn logarithm(arg: &Value) -> EvalResult {
+	let value: f64;
+	let base: Option<f64>;
+	match arg {
+		Value::Tuple(tuple)
+			=>	{
+				let len = tuple.len();
+				if len != 2 { return Err(EvalexprError::WrongOperatorArgumentAmount { expected: 2, actual: len }) }
+
+				let i_value = tuple.get(0).unwrap();
+				if		let Value::Float(float)	= i_value { value = float.clone(); }
+				else if	let Value::Int(int)		= i_value { value = int.clone() as f64; }
+				else { return Err(EvalexprError::expected_number(i_value.clone())); }
+
+				let i_base = tuple.get(1).unwrap();
+				if		let Value::Float(float)	= i_value { base = Some(float.clone()); }
+				else if	let Value::Int(int)		= i_value { base = Some(int.clone() as f64); }
+				else { return Err(EvalexprError::expected_number(i_base.clone())); }
+			},
+		Value::Float(float)
+			=>	{
+				value = float.clone();
+				base = None;
+			},
+		Value::Int(int)
+			=>	{
+				value = int.clone() as f64;
+				base = None;
+			}
+		_	=>	return Err(EvalexprError::CustomMessage("Expected numbers.".to_owned()))
+	}
+
+	if let Some(base) = base { Ok(value.log(base).into()) }
+	else { Ok(value.ln().into()) }
+}
+
+pub fn sine(arg: &Value) -> EvalResult {
+	Ok(
+		if		let Value::Float(float)	= arg { float.clone() }
+		else if	let Value::Int(int)		= arg { int.clone() as f64 }
+		else { return Err(EvalexprError::expected_number(arg.clone())) }
+		.sin().into()
+	)
+}
+
+pub fn square_root(arg: &Value) -> EvalResult {
+	Ok(
+		if		let Value::Float(float)	= arg { float.clone() }
+		else if	let Value::Int(int)		= arg { int.clone() as f64 }
+		else { return Err(EvalexprError::expected_number(arg.clone())) }
+		.sqrt().into()
+	)
+}
+
+pub fn tangent(arg: &Value) -> EvalResult {
+	Ok(
+		if		let Value::Float(float)	= arg { float.clone() }
+		else if	let Value::Int(int)		= arg { int.clone() as f64 }
+		else { return Err(EvalexprError::expected_number(arg.clone())) }
+		.tan().into()
+	)
+}
+
+
+//	Data Science
+pub fn average(arg: &Value) -> EvalResult {
+	if let Value::Tuple(args) = arg {
+		let len = args.len() as f64;
+		let mut total = 0f64;
+
+		for arg in args {
+			total +=
+				if		let Value::Float(float) = arg { float.clone() }
+				else if	let Value::Int(int)		= arg { int.clone() as f64 }
+				else { todo!() };
+		}
+
+		Ok( (total / len).into() )
+	} else { todo!() }
+}
+
+//	Radix conversion
+pub fn binary(arg: &Value) -> EvalResult {
+	if let Value::Int(int) = arg { Ok( format!("0b{:b}", int).into() ) }
+	else if let Value::String(string) = arg { util::parse_radix("0b", 2, string) }
+	else { Err(EvalexprError::expected_number_or_string(arg.clone())) }
+}
+
+pub fn hexadecimal(arg: &Value) -> EvalResult {
+	if let Value::Int(int) = arg { Ok( format!("0x{:X}", int).into() ) }
+	else if let Value::String(string) = arg { util::parse_radix("0x", 16, string) }
+	else { Err(EvalexprError::expected_number_or_string(arg.clone())) }
+}
+
+pub fn octal(arg: &Value) -> EvalResult {
+	if let Value::Int(int) = arg { Ok( format!("0o{:#o}", int).into() ) }
+	else if let Value::String(string) = arg { util::parse_radix("0o", 8, string) }
+	else { Err(EvalexprError::expected_number_or_string(arg.clone())) }
+}
+
diff --git a/src/context/mod.rs b/src/context/mod.rs
new file mode 100644
index 0000000..3023be6
--- /dev/null
+++ b/src/context/mod.rs
@@ -0,0 +1,68 @@
+
+pub mod global;
+pub mod helper;
+
+
+use pico_args::Arguments;
+use evalexpr::{
+	context_map,
+
+	ContextWithMutableVariables,
+	HashMapContext,
+	Value
+};
+
+use crate::flag;
+
+pub fn build(args: &mut Arguments) -> HashMapContext {
+	let mut output =
+		if !args.contains(flag::EMPTY_CONTEXT) {
+			context_map! {
+				//	globals
+				"c"		=>	global::LIGHT_SPEED,
+				"e"		=>	global::EULER,
+				"phi"	=>	global::GOLDEN_RATIO,
+				"pi"	=>	global::PI,
+				"√2"	=>	global::ROOT_TWO,
+
+				//	math functions
+				"cos"	=>	Function::new(|arg| helper::cosine(arg)),
+				"fix"	=>	Function::new(|arg| helper::fix(arg)),
+				"log"	=>	Function::new(|arg| helper::logarithm(arg)),
+				"sin"	=>	Function::new(|arg| helper::sine(arg)),
+				"sqrt"	=>	Function::new(|arg| helper::square_root(arg)),
+				"tan"	=>	Function::new(|arg| helper::tangent(arg)),
+
+				//	data science functions
+				"avg"	=>	Function::new(|arg| helper::average(arg)),
+
+				//	radix functions
+				"bin"	=>	Function::new(|arg| helper::binary(arg)),
+				"hex"	=>	Function::new(|arg| helper::hexadecimal(arg)),
+				"oct"	=>	Function::new(|arg| helper::octal(arg)),
+
+				//	character aliases
+				"ϕ"		=>	global::GOLDEN_RATIO,
+				"π"		=>	global::PI,
+				"√"		=>	Function::new(|arg| helper::square_root(arg))
+			}.unwrap()
+		} else { HashMapContext::new() };
+
+	while let Ok(value) = args.value_from_str::<&str, String>(flag::SET) {
+		let split: Vec<&str> = value.split('=').collect();
+		if split.len() == 2 {
+			let key = split[0].to_owned();
+
+			let value_str = split[1];
+			let value =
+				if let Ok(integer) = value_str.parse::<i64>() { Value::Int(integer) }
+				else if let Ok(float) = value_str.parse::<f64>() { Value::Float(float) }
+				else { Value::from(value_str) };
+
+			output.set_value(key, value).ok(); }
+		else { std::process::exit(1); }
+	}
+
+	output
+}
+
diff --git a/src/flag.rs b/src/flag.rs
new file mode 100644
index 0000000..c3fa1d7
--- /dev/null
+++ b/src/flag.rs
@@ -0,0 +1,7 @@
+
+pub const EMPTY_CONTEXT:	[&str;2]	=	[ "-E", "--empty"];
+pub const HELP:				[&str;2]	=	[ "-h", "--help" ];
+pub const QUIET:			[&str;2]	=	[ "-q", "--quiet" ];
+pub const SET:				&str		=	"--set";
+pub const VERSION:			[&str;2]	=	[ "-V", "--version" ];
+
diff --git a/src/helper.rs b/src/helper.rs
deleted file mode 100644
index 02c57de..0000000
--- a/src/helper.rs
+++ /dev/null
@@ -1,147 +0,0 @@
-use evalexpr::{
-	Value,
-
-	EvalexprError
-};
-
-use crate::util;
-
-pub type EvalResult = Result<Value, EvalexprError>;
-
-
-//	Mathematics
-pub fn fix(arg: &Value) -> EvalResult {
-	let args = arg.as_tuple()?;
-
-	let count = args.len();
-	if count != 2 {
-		return Err(EvalexprError::WrongFunctionArgumentAmount { expected: 2, actual: count });
-	}
-
-	let float = args[0].as_float()?;
-	let figures = args[1].as_int()?;
-
-	let operand: f64 = i64::pow(10, figures as u32) as f64;
-	let output = f64::round(float * operand) / operand;
-	return Ok(output.into());
-}
-
-pub fn logarithm(arg: &Value) -> EvalResult {
-	let arguments: Vec<Value>;
-	let count: usize;
-	if arg.is_tuple() {
-		arguments = arg.as_tuple()?;
-		count = arguments.len();
-	} else if arg.is_float() {
-		arguments = vec!(arg.as_float()?.into());
-		count = 1;
-	} else if arg.is_int() {
-		arguments = vec!((arg.as_int()? as f64).into());
-		count = 1;
-	} else {
-		return Err(EvalexprError::CustomMessage("Expected numbers".to_string()));
-	}
-
-	let output: Value;
-	match count {
-		1 => {
-			let argument = &arguments[0];
-			if !argument.is_number() {
-				return Err(EvalexprError::CustomMessage("Expected number".to_string()));
-			}
-			let number = if argument.is_float() { argument.as_float()? } else { argument.as_int()? as f64 };
-			output = number.ln().into();
-		},
-		2 => {
-			let arg_value = &arguments[0];
-			let arg_base = &arguments[1];
-			if !(arg_value.is_number() && arg_base.is_number()) {
-				return Err(EvalexprError::CustomMessage("Expected two numbers".to_string()));
-			}
-			let value: f64 = if arg_value.is_float() { arg_value.as_float()? } else { arg_value.as_int()? as f64 };
-			let base: f64 = if arg_base.is_float() { arg_base.as_float()? } else { arg_base.as_int()? as f64 };
-			output = value.log(base).into();
-		},
-		_ => {
-			return Err(EvalexprError::WrongFunctionArgumentAmount { expected: 2, actual: count });
-		}
-	}
-	return Ok(output);
-}
-
-pub fn square_root(arg: &Value) -> EvalResult {
-	if !arg.is_number() {
-		return Err(EvalexprError::CustomMessage("Expected a number.".to_string()));
-	}
-	let value: f64 = if arg.is_float() { arg.as_float()? } else { arg.as_int()? as f64 };
-	return Ok(value.sqrt().into());
-}
-
-
-//	Data Science
-pub fn average(arg: &Value) -> EvalResult {
-	let arguments = arg.as_tuple()?;
-	let count = arguments.len() as i64;
-	let mut is_float = false;
-	let mut total_i = 0i64;
-	let mut total_f = 0f64;
-
-	for argument in arguments {
-		if let Value::Float(float) = argument {
-			if !is_float {
-				total_f = total_i as f64;
-				is_float = true;
-			}
-			total_f += float;
-		} else if let Value::Int(int) = argument {
-			if is_float {
-				total_f += int as f64;
-			} else {
-				total_i += int;
-			}
-		}
-	}
-	
-	let result_i: i64;
-	let result_f: f64;
-	if !is_float {
-		is_float = total_i % count == 0;
-		total_f = total_i as f64;
-	}
-
-	if is_float {
-		result_f = total_f / (count as f64);
-		return Ok(result_f.into());
-	} else {
-		result_i = total_i / count;
-		return Ok(result_i.into());
-	}
-}
-
-//	Radix conversion
-pub fn binary(arg: &Value) -> EvalResult {
-	if !arg.is_string() {
-		let num = arg.as_int()?;
-		let fmt = format!("0b{:b}", num);
-		return Ok(fmt.into());
-	}
-	util::parse_radix("0b", 2, arg)
-}
-
-pub fn hexadecimal(arg: &Value) -> EvalResult {
-	if !arg.is_string() {
-		let num = arg.as_int()?;
-		let fmt = format!("0x{:X}", num);
-		return Ok(fmt.into());
-	}
-	util::parse_radix("0x", 16, arg)
-}
-
-pub fn octal(arg: &Value) -> EvalResult {
-	if !arg.is_string() {
-		let num = arg.as_int()?;
-		let fmt = format!("{:#o}", num);
-		return Ok(fmt.into());
-	}
-	util::parse_radix("0o", 8, arg)
-}
diff --git a/src/main.rs b/src/main.rs
index 334f03c..4558694 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,119 +4,118 @@ use std::{
 		stdin,
 		stdout,
 
+		IsTerminal,
+		Read,
 		Write
-	}
+	},
+	process::exit
 };
 
 use evalexpr::{
-	context_map,
 	eval_with_context_mut,
+
 	ContextWithMutableVariables,
+	EvalexprError,
 	HashMapContext,
 	Value
 };
+use pico_args::Arguments;
+use rustyline::DefaultEditor;
 use termion::{
 	color,
 	style
 };
 
-mod global;
-mod helper;
+mod context;
+mod flag;
 mod util;
 
 pub const VERSION: &str = env!("CARGO_PKG_VERSION");
 
 fn main() {
-	//	build eval context
-	let mut context = context_map! {
-		//	globals
-		"c"		=>	global::LIGHT_SPEED,
-		"e"		=>	global::EULER,
-		"phi"	=>	global::GOLDEN_RATIO,
-		"pi"	=>	global::PI,
-		"√2"	=>	global::ROOT_TWO,
+	let mut args = Arguments::from_env();
 
-		//	math functions
-		"fix"	=>	Function::new(|arg| helper::fix(arg)),
-		"log"	=>	Function::new(|arg| helper::logarithm(arg)),
-		"sqrt"	=>	Function::new(|arg| helper::square_root(arg)),
+	//	handle breaking flags
+	if args.contains(flag::HELP) {
+		help_text();
+		return;
+	}
+	if args.contains(flag::VERSION) {
+		version_text();
+		return;
+	}
 
-		//	data science functions
-		"avg"	=>	Function::new(|arg| helper::average(arg)),
-
-		//	radix functions
-		"bin"	=>	Function::new(|arg| helper::binary(arg)),
-		"hex"	=>	Function::new(|arg| helper::hexadecimal(arg)),
-		"oct"	=>	Function::new(|arg| helper::octal(arg)),
-
-		//	character aliases
-		"ϕ"		=>	global::GOLDEN_RATIO,
-		"π"		=>	global::PI,
-		"√"		=>	Function::new(|arg| helper::square_root(arg))
-	}.unwrap();
+	let mut context = context::build(&mut args);
+	let is_terminal = stdin().is_terminal() && stdout().is_terminal();
+	let quiet = args.contains(flag::QUIET) || !is_terminal;
 
 	//	collect args and evaluate if present
-	let expressions: Vec<String> = env::args().skip(1).collect();
+	let expressions = args.finish();
 	if expressions.len() > 0 {
 		for expression in expressions {
-			match expression.as_str() {
-				"help"	=>	help_text(),
-				_		=>	do_eval(expression, &mut context)
-			}
+			let expression: String = expression.to_string_lossy().into();
+			eval(&expression, &mut context, quiet);
 		}
 	} else {
-		//	enter interactive mode if no args are given
-		println!("{}quickmaths v{}{}\n{}Interactive Mode{}", style::Bold, VERSION, style::Reset, style::Faint, style::Reset);
-		loop {
-			print!("> ");
-			stdout().flush().unwrap();
-			let mut i_line = String::new();
-			let line_result = stdin().read_line(&mut i_line);
-			if line_result.is_err() {
-				break;
+		if !is_terminal {
+			let mut buffer = String::with_capacity(0);
+			if let Ok(_) = stdin().read_to_string(&mut buffer) {
+				for expression in buffer.lines() {
+					eval(&expression.to_string(), &mut context, quiet);
+				}
 			}
-			let line = i_line.trim().to_string();
-			match line.as_str() {
-				""		|
-				"exit"	=>	break,
-				_		=>	do_eval(line, &mut context)
+		} else if let Ok(mut rl) = DefaultEditor::new() {
+			//	enter interactive mode if no args are given
+			version_text();
+			println!("{}Interactive Mode{}", style::Faint, style::Reset);
+			loop {
+				if let Ok(line) = rl.readline("> ") {
+					match line.as_str() {
+						""		|
+						"exit"	=>	break,
+						_		=>	eval(&line, &mut context, quiet)
+					}
+				}
+				reset();
 			}
-			reset();
 		}
 	}
 }
 
-fn do_eval(i_expression: String, context: &mut HashMapContext) {
-	let expression = i_expression.as_str();
+fn eval(expression: &str, context: &mut HashMapContext, quiet: bool) {
 	let result = eval_with_context_mut(expression, context);
+
+	if let Ok(ref result) = result { context.set_value("$".to_owned(), result.clone()).ok(); }
+
+	if quiet {
+		if let Ok(result) = result { println!("{result}") }
+		else { exit(1) }
+	} else { format(expression, result) }
+}
+
+fn format(expression: &str, result: Result<Value, EvalexprError>) {
 	if let Ok(result) = result {
-		//	display empty result
-		if result.is_empty() {
+		if !result.is_empty() {
+			let delimiter =
+				match result {
+					Value::Boolean(_)	=>	"is",
+					Value::String(_)	=>	"=>",
+					_					=>	"="
+				};
+			println!(
+				"{faint}{italic}{expression}{reset} {delimiter} {bold}{result}",
+				bold	=	style::Bold,
+				faint	=	style::Faint,
+				italic	=	style::Italic,
+				reset	=	style::Reset
+			);
+		} else {
 			println!(
 				"{green}✓ {bold}{expression}",
 				bold = style::Bold,
 				green = color::Fg(color::Green)
 			);
-			return;
 		}
-
-		//	get appropriate symbol for result by type
-		let delimiter;
-		match result {
-			Value::Boolean(_bool)		=>	delimiter = "is",
-			Value::String(ref _str)		=>	delimiter = "=>",
-			_							=>	delimiter = "="
-		}
-		println!(
-			"{faint}{italic}{expression}{reset} {delimiter} {bold}{result}",
-			bold = style::Bold,
-			faint = style::Faint,
-			italic = style::Italic,
-			reset = style::Reset
-		);
-
-		//	set "last" variable
-		context.set_value("$".to_string(), result).ok();
 	} else {
 		println!(
 			"{red}✕ {bold}{expression}",
@@ -131,16 +130,17 @@ fn reset() {
 	stdout().flush().unwrap();
 }
 
+fn version_text() {
+	println!("qm v{VERSION}");
+}
+
 fn help_text() {
+	version_text();
 	println!(
-		"{bold}quickmaths v{version}{reset}
-Valerie Wolfe <sleeplessval@gmail.com>
+"Valerie Wolfe <sleeplessval@gmail.com>
 A mathematical expression evaluator written in Rust.
 
 usage:
-   qm [EXPRESSION]...",
-		bold = style::Bold,
-		reset = style::Reset,
-		version = crate::VERSION
+   qm [EXPRESSION]..."
 	);
 }
diff --git a/src/util.rs b/src/util.rs
index 1cc557e..6daadbf 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -1,18 +1,10 @@
-use evalexpr::{
-	Value,
-	
-	EvalexprError
-};
 
-pub(crate) fn parse_radix(prefix: &str, base: u32, arg: &Value) -> Result<Value, EvalexprError> {
-	let i_parse = arg.as_string()?;
-	let parse = i_parse.strip_prefix(prefix).unwrap_or(i_parse.as_str());
+use evalexpr::{ EvalexprError, Value };
 
-	let i_result = i64::from_str_radix(parse, base);
-	if i_result.is_err() {
-		return Err(EvalexprError::CustomMessage("failed to parse integer from string".to_string()));
-	}
-	let result = i_result.ok();
+pub fn parse_radix(prefix: &str, base: u32, arg: &str) -> Result<Value, EvalexprError> {
+	let parse = arg.strip_prefix(prefix).unwrap_or(arg);
 
-	return Ok(result.unwrap().into());
+	if let Ok(int) = i64::from_str_radix(parse, base) { Ok(int.into()) }
+	else { Err(EvalexprError::CustomMessage("failed to parse integer from string".to_string())) }
 }
+