diff --git a/unix-mode b/unix-mode
deleted file mode 160000
index 0bbf1ae..0000000
--- a/unix-mode
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 0bbf1aed9ad583017b90aa2c03d3f7870538a914
diff --git a/unix-mode/Cargo.toml b/unix-mode/Cargo.toml
new file mode 100644
index 0000000..56c7e23
--- /dev/null
+++ b/unix-mode/Cargo.toml
@@ -0,0 +1,13 @@
+[package]
+name = "unix-mode"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+libc = { workspace = true }
+
+[dependencies.bitflags]
+package = "bitflags-mini"
+path = "../bitflags-mini"
diff --git a/unix-mode/src/bit.rs b/unix-mode/src/bit.rs
new file mode 100644
index 0000000..a365c25
--- /dev/null
+++ b/unix-mode/src/bit.rs
@@ -0,0 +1,98 @@
+use bitflags::BitFlags;
+use std::ops::{BitAnd, BitAndAssign, BitOr, BitOrAssign};
+
+/// Unix permission bit flags
+#[derive(Clone, Copy, PartialEq)]
+pub enum Bit {
+    Suid = 0o4000,
+    Sgid = 0o2000,
+    Sticky = 0o1000,
+    URead = 0o400,
+    UWrite = 0o200,
+    UExec = 0o100,
+    GRead = 0o40,
+    GWrite = 0o20,
+    GExec = 0o10,
+    ORead = 0o4,
+    OWrite = 0o2,
+    OExec = 0o1,
+}
+
+impl BitAnd<u32> for Bit {
+    type Output = u32;
+
+    fn bitand(self, rhs: u32) -> Self::Output {
+        self as u32 & rhs
+    }
+}
+
+impl BitAnd<Bit> for u32 {
+    type Output = u32;
+
+    fn bitand(self, rhs: Bit) -> Self::Output {
+        self & rhs as u32
+    }
+}
+
+impl BitAnd for Bit {
+    type Output = u32;
+
+    fn bitand(self, rhs: Self) -> Self::Output {
+        self as u32 & rhs as u32
+    }
+}
+
+impl BitAndAssign<Bit> for u32 {
+    fn bitand_assign(&mut self, rhs: Bit) {
+        *self = *self & rhs;
+    }
+}
+
+impl BitOr<u32> for Bit {
+    type Output = u32;
+
+    fn bitor(self, rhs: u32) -> Self::Output {
+        self as u32 | rhs
+    }
+}
+
+impl BitOr<Bit> for u32 {
+    type Output = u32;
+
+    fn bitor(self, rhs: Bit) -> Self::Output {
+        self | rhs as u32
+    }
+}
+
+impl BitOr for Bit {
+    type Output = u32;
+
+    fn bitor(self, rhs: Self) -> Self::Output {
+        self as u32 | rhs as u32
+    }
+}
+
+impl BitOrAssign<Bit> for u32 {
+    fn bitor_assign(&mut self, rhs: Bit) {
+        *self = *self | rhs;
+    }
+}
+
+impl Bit {
+    pub fn as_char(&self, mode: u32) -> char {
+        if mode & *self != 0 {
+            match self {
+                Self::Suid | Self::Sgid => 's',
+                Self::Sticky => 't',
+                Self::URead | Self::GRead | Self::ORead => 'r',
+                Self::UWrite | Self::GWrite | Self::OWrite => 'w',
+                Self::UExec if mode.contains(Self::Suid) => 's',
+                Self::GExec if mode.contains(Self::Sgid) => 's',
+                Self::OExec if mode.contains(Self::Sticky) => 't',
+                Self::UExec | Self::GExec | Self::OExec => 'x',
+            }
+        } else {
+            '-'
+        }
+    }
+}
diff --git a/unix-mode/src/lib.rs b/unix-mode/src/lib.rs
new file mode 100644
index 0000000..c5b6697
--- /dev/null
+++ b/unix-mode/src/lib.rs
@@ -0,0 +1,141 @@
+//! Functions for parsing and managing permissions
+mod bit;
+mod parser;
+mod who;
+use std::fmt::{self, Write};
+
+pub use {
+    bit::Bit,
+    parser::{ParseError, Parser},
+    who::Who,
+};
+
+/// Gets the umask for the current user
+#[must_use]
+pub fn get_umask() -> u32 {
+    let mask = unsafe { libc::umask(0) };
+    let _mask = unsafe { libc::umask(mask) };
+    mask
+}
+
+/// Functions for extracting information about Unix modes
+pub trait Mode {
+    /// Returns a string representing permissions in symbolic format
+    /// including file type
+    fn mode_string_full(&self) -> Result<String, fmt::Error>;
+
+    /// Returns a string representing permissions in symbolic format
+    /// minus file type
+    fn mode_string(&self) -> Result<String, fmt::Error>;
+}
+
+impl Mode for u32 {
+    fn mode_string_full(&self) -> Result<String, fmt::Error> {
+        let b = if self & 0o40000 != 0 && self & 0o20000 != 0 {
+            'b'
+        } else if self & 0o40000 != 0 {
+            'd'
+        } else if self & 0o20000 != 0 {
+            'c'
+        } else {
+            '-'
+        };
+        let mut s = String::new();
+        write!(s, "{b}")?;
+        [
+            Bit::URead,
+            Bit::UWrite,
+            Bit::UExec,
+            Bit::GRead,
+            Bit::GWrite,
+            Bit::GExec,
+            Bit::ORead,
+            Bit::OWrite,
+            Bit::OExec,
+        ]
+        .iter()
+        .try_for_each(|b| write!(s, "{}", b.as_char(*self)))?;
+        Ok(s)
+    }
+
+    fn mode_string(&self) -> Result<String, fmt::Error> {
+        let mut s = String::new();
+        [
+            Bit::URead,
+            Bit::UWrite,
+            Bit::UExec,
+            Bit::GRead,
+            Bit::GWrite,
+            Bit::GExec,
+            Bit::ORead,
+            Bit::OWrite,
+            Bit::OExec,
+        ]
+        .iter()
+        .try_for_each(|b| write!(s, "{}", b.as_char(*self)))?;
+        Ok(s)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn getumask() {
+        let mask = unsafe { libc::umask(0o22) };
+        assert_eq!(get_umask(), 0o022);
+        unsafe {
+            libc::umask(mask);
+        }
+    }
+
+    #[test]
+    fn display_bits_dir() {
+        let m: u32 = 0o40755;
+        let s = m.mode_string_full().unwrap();
+        assert_eq!(s.as_str(), "drwxr-xr-x")
+    }
+
+    #[test]
+    fn display_bits_char() {
+        let m: u32 = 0o20666;
+        let s = m.mode_string_full().unwrap();
+        assert_eq!(s.as_str(), "crw-rw-rw-")
+    }
+
+    #[test]
+    fn display_bits_block() {
+        let m: u32 = 0o60660;
+        let s = m.mode_string_full().unwrap();
+        assert_eq!(s.as_str(), "brw-rw----")
+    }
+
+    #[test]
+    fn display_bits_file() {
+        let m: u32 = 0o100644;
+        let s = m.mode_string_full().unwrap();
+        assert_eq!(s.as_str(), "-rw-r--r--")
+    }
+
+    #[test]
+    fn display_bits_suid() {
+        let m: u32 = 0o104755;
+        let s = m.mode_string_full().unwrap();
+        assert_eq!(s.as_str(), "-rwsr-xr-x")
+    }
+
+    #[test]
+    fn display_bits_sgid() {
+        let m: u32 = 0o102755;
+        let s = m.mode_string_full().unwrap();
+        assert_eq!(s.as_str(), "-rwxr-sr-x")
+    }
+
+    #[test]
+    fn display_bits_sticky() {
+        let m: u32 = 0o41777;
+        let s = m.mode_string_full().unwrap();
+        assert_eq!(s.as_str(), "drwxrwxrwt")
+    }
+}
diff --git a/unix-mode/src/parser.rs b/unix-mode/src/parser.rs
new file mode 100644
index 0000000..f801150
--- /dev/null
+++ b/unix-mode/src/parser.rs
@@ -0,0 +1,386 @@
+use super::{get_umask, Bit, Who};
+use bitflags::BitFlags;
+use std::{error, fmt::Display, num::ParseIntError};
+
+/// Errors which might occur when parsing Unix permissions from a string
+#[derive(Debug, PartialEq)]
+pub enum ParseError {
+    /// the given `Bit` cannot be set for the given `Who`
+    InvalidBit,
+    /// the character is not recognized
+    InvalidChar,
+    /// the specified octal mode is invalid
+    OutsideRange,
+    ParseIntError(ParseIntError),
+    /// no `Op` is set when parsing a `Bit`
+    NoOpSet,
+}
+
+impl Display for ParseError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{self:?}")
+    }
+}
+
+impl error::Error for ParseError {}
+
+impl From<ParseIntError> for ParseError {
+    fn from(value: ParseIntError) -> Self {
+        Self::ParseIntError(value)
+    }
+}
+
+#[derive(PartialEq)]
+/// Operations which can be performed to add, remove, or set explicitly the given
+/// `Bit` for the given `Who`
+enum Op {
+    /// `Bit`s will be added for `Who`
+    Add,
+    /// `Bit`s will be remoed for `Who`
+    Remove,
+    /// `Bit`s will be set to exactly the specified arrangement
+    Equals,
+}
+
+/// A parser for octal and symbolic permissions. `Parser::default` creates an
+/// instance which applies the given operations to the default setting for the
+/// current user's umask. `Parser::new` creates a parser which applies the given
+/// operations to the specified beginning set of permissions. Therefore, when
+/// creating new files or directories use `Parser::default`, while `Parser::new`
+/// should be used for setting permissions of already existing files or directories.
+pub struct Parser {
+    mode: u32,
+    op: Option<Op>,
+    who: u32,
+    bits: u32,
+}
+
+impl Default for Parser {
+    fn default() -> Self {
+        let umask = get_umask();
+        let mut mode = 0o0666;
+        mode &= umask;
+        Self {
+            mode,
+            op: None,
+            who: 0,
+            bits: 0,
+        }
+    }
+}
+
+impl Parser {
+    #[must_use]
+    pub fn new(mode: u32) -> Self {
+        Self {
+            mode,
+            op: None,
+            who: 0,
+            bits: 0,
+        }
+    }
+
+    fn parse_octal(value: &str) -> Result<u32, ParseError> {
+        let m = u32::from_str_radix(value, 8)?;
+        if m <= 0o7777 {
+            Ok(m)
+        } else {
+            Err(ParseError::OutsideRange)
+        }
+    }
+
+    fn add_who(&mut self, who: Who) -> Result<(), ParseError> {
+        if self.op.is_some() || !self.bits == 0 {
+            Err(ParseError::InvalidChar)
+        } else {
+            self.who |= who;
+            Ok(())
+        }
+    }
+
+    fn set_op(&mut self, op: Op) -> Result<(), ParseError> {
+        if self.op.is_some() || !self.bits == 0 {
+            Err(ParseError::InvalidChar)
+        } else {
+            self.op = Some(op);
+            if self.who == 0 {
+                self.who |= 0o111;
+            }
+            Ok(())
+        }
+    }
+
+    fn push_read_bits(&mut self) -> Result<(), ParseError> {
+        if self.op.is_none() {
+            Err(ParseError::NoOpSet)
+        } else {
+            if self.who.contains(Who::User) {
+                self.bits |= Bit::URead;
+            }
+            if self.who.contains(Who::Group) {
+                self.bits |= Bit::GRead;
+            }
+            if self.who.contains(Who::Other) {
+                self.bits |= Bit::ORead;
+            }
+            Ok(())
+        }
+    }
+
+    fn push_write_bits(&mut self) -> Result<(), ParseError> {
+        if self.op.is_none() {
+            Err(ParseError::NoOpSet)
+        } else {
+            if self.who.contains(Who::User) {
+                self.bits |= Bit::UWrite;
+            }
+            if self.who.contains(Who::Group) {
+                self.bits |= Bit::GWrite;
+            }
+            if self.who.contains(Who::Other) {
+                self.bits |= Bit::OWrite;
+            }
+            Ok(())
+        }
+    }
+
+    fn push_exec_bits(&mut self) -> Result<(), ParseError> {
+        if self.op.is_none() {
+            Err(ParseError::NoOpSet)
+        } else {
+            if self.who.contains(Who::User) {
+                self.bits |= Bit::UExec;
+            }
+            if self.who.contains(Who::Group) {
+                self.bits |= Bit::GExec;
+            }
+            if self.who.contains(Who::Other) {
+                self.bits |= Bit::OExec;
+            }
+            Ok(())
+        }
+    }
+
+    fn push_suid_sgid(&mut self) -> Result<(), ParseError> {
+        if self.who == 0 || self.who.contains(Who::Other) {
+            return Err(ParseError::InvalidBit);
+        } else if self.op.is_none() {
+            return Err(ParseError::NoOpSet);
+        }
+        if self.who.contains(Who::User) {
+            self.bits |= Bit::Suid;
+        }
+        if self.who.contains(Who::Group) {
+            self.bits |= Bit::Sgid;
+        }
+        Ok(())
+    }
+
+    fn push_sticky(&mut self) -> Result<(), ParseError> {
+        if self.who == 0 || self.who.contains(Who::User) || self.who.contains(Who::Group) {
+            return Err(ParseError::InvalidBit);
+        } else if self.op.is_none() {
+            return Err(ParseError::NoOpSet);
+        }
+        if self.who.contains(Who::Other) {
+            self.bits |= Bit::Sticky;
+        }
+        Ok(())
+    }
+
+    fn add_bits(&mut self) {
+        self.mode |= self.bits;
+    }
+
+    fn remove_bits(&mut self) {
+        self.mode &= !self.bits;
+    }
+
+    fn set_bits(&mut self) -> Result<(), ParseError> {
+        match self.op {
+            Some(Op::Add) => self.add_bits(),
+            Some(Op::Remove) => self.remove_bits(),
+            Some(Op::Equals) => {
+                if self.who.contains(Who::User) {
+                    self.mode &= !(0o4700);
+                }
+                if self.who.contains(Who::Group) {
+                    self.mode &= !(0o2070);
+                }
+                if self.who.contains(Who::Other) {
+                    self.mode &= !(0o1007);
+                }
+                self.add_bits();
+            }
+            None => return Err(ParseError::NoOpSet),
+        }
+        Ok(())
+    }
+
+    fn reset(&mut self) {
+        self.who = 0;
+        self.op = None;
+        self.bits = 0;
+    }
+
+    #[must_use]
+    pub fn mode(&self) -> u32 {
+        self.mode
+    }
+
+    /// Parses a numerical mode from either an octal string or symbolic representation
+    /// and applies those permissions to the starting set of permissions.
+    /// # Errors
+    /// Returns `ParseError` if:
+    /// - invalid digit
+    /// - no operation specified
+    /// - more than one operation specified at a time (multiple operations can
+    ///   be specified separated by comma)
+    /// - the specified bit cannot be applied to the specified `Who`
+    /// - bits are specified before operations
+    /// - the specified octal mode is greater than 0o7777
+    pub fn parse(&mut self, value: &str) -> Result<u32, ParseError> {
+        match Self::parse_octal(value) {
+            Ok(mode) => {
+                self.mode = mode;
+                return Ok(mode);
+            }
+            Err(e) => {
+                if e == ParseError::OutsideRange {
+                    return Err(e);
+                }
+            }
+        }
+        for c in value.chars() {
+            match c {
+                'u' => self.add_who(Who::User)?,
+                'g' => self.add_who(Who::Group)?,
+                'o' => self.add_who(Who::Other)?,
+                'a' => {
+                    self.add_who(Who::User)?;
+                    self.add_who(Who::Group)?;
+                    self.add_who(Who::Other)?;
+                }
+                '-' => self.set_op(Op::Remove)?,
+                '+' => self.set_op(Op::Add)?,
+                '=' => self.set_op(Op::Equals)?,
+                'r' => self.push_read_bits()?,
+                'w' => self.push_write_bits()?,
+                'x' => self.push_exec_bits()?,
+                's' => self.push_suid_sgid()?,
+                't' => self.push_sticky()?,
+                ',' => {
+                    self.set_bits()?;
+                    self.reset();
+                }
+                _ => return Err(ParseError::InvalidChar),
+            }
+        }
+        self.set_bits()?;
+        self.reset();
+        Ok(self.mode)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn add() {
+        let mut parser = Parser::new(0o644);
+        let mode = parser.parse("ug+x");
+        assert_eq!(mode, Ok(0o754));
+    }
+
+    #[test]
+    fn remove() {
+        let mut parser = Parser::new(0o777);
+        let mode = parser.parse("go-wx");
+        assert_eq!(mode, Ok(0o744));
+    }
+
+    #[test]
+    fn octal() {
+        let mut parser = Parser::default();
+        let mode = parser.parse("4755");
+        assert_eq!(mode, Ok(0o4755));
+    }
+
+    #[test]
+    fn equals() {
+        let mut parser = Parser::new(0o701);
+        let mode = parser.parse("ugo=rw");
+        assert_eq!(mode, Ok(0o666));
+    }
+
+    #[test]
+    fn o_equals() {
+        let mut parser = Parser::new(0o752);
+        let mode = parser.parse("o=rx");
+        assert_eq!(mode, Ok(0o755));
+    }
+
+    #[test]
+    fn empty_who() {
+        let mut parser = Parser::new(0o644);
+        let mode = parser.parse("+x");
+        assert_eq!(mode, Ok(0o755));
+    }
+
+    #[test]
+    fn compound_ops() {
+        let mut parser = Parser::new(0o666);
+        let mode = parser.parse("u+x,g-w,o-r");
+        assert_eq!(mode, Ok(0o742));
+    }
+
+    #[test]
+    fn compount_ops2() {
+        let mut parser = Parser::new(0o4444);
+        let mode = parser.parse("u+w,ug+x,o=rx,u-s");
+        assert_eq!(mode, Ok(0o755));
+    }
+
+    #[test]
+    fn invalid_sticky_bit() {
+        let mut parser = Parser::default();
+        let mode = parser.parse("u+t");
+        assert_eq!(mode, Err(ParseError::InvalidBit));
+    }
+
+    #[test]
+    fn invalid_s() {
+        let mut parser = Parser::default();
+        let mode = parser.parse("+s");
+        assert_eq!(mode, Err(ParseError::InvalidBit));
+    }
+
+    #[test]
+    fn outside_range() {
+        let mut parser = Parser::default();
+        let mode = parser.parse("10000");
+        assert_eq!(mode, Err(ParseError::OutsideRange))
+    }
+
+    #[test]
+    fn no_op() {
+        let mut parser = Parser::default();
+        let mode = parser.parse("rws");
+        assert_eq!(mode, Err(ParseError::NoOpSet));
+    }
+
+    #[test]
+    fn ordering_error() {
+        let mut parser = Parser::default();
+        let mode = parser.parse("ux+s");
+        assert_eq!(mode, Err(ParseError::NoOpSet));
+    }
+
+    #[test]
+    fn ordering_error1() {
+        let mut parser = Parser::default();
+        let mode = parser.parse("x+s");
+        assert_eq!(mode, Err(ParseError::NoOpSet));
+    }
+}
diff --git a/unix-mode/src/who.rs b/unix-mode/src/who.rs
new file mode 100644
index 0000000..f1f21c8
--- /dev/null
+++ b/unix-mode/src/who.rs
@@ -0,0 +1,48 @@
+use std::ops::{BitAnd, BitAndAssign, BitOr, BitOrAssign};
+
+#[derive(PartialEq)]
+/// The granularity of the given permissions
+pub enum Who {
+    /// applies for the current user
+    User = 0o100,
+    /// applies for the current group
+    Group = 0o10,
+    /// applies for everyone else
+    Other = 0o1,
+}
+
+impl BitAnd<Who> for u32 {
+    type Output = u32;
+
+    fn bitand(self, rhs: Who) -> Self::Output {
+        self & rhs as u32
+    }
+}
+
+impl BitAnd<u32> for Who {
+    type Output = u32;
+
+    fn bitand(self, rhs: u32) -> Self::Output {
+        self as u32 & rhs
+    }
+}
+
+impl BitAndAssign<Who> for u32 {
+    fn bitand_assign(&mut self, rhs: Who) {
+        *self = *self & rhs;
+    }
+}
+
+impl BitOr<Who> for u32 {
+    type Output = u32;
+
+    fn bitor(self, rhs: Who) -> Self::Output {
+        self | rhs as u32
+    }
+}
+
+impl BitOrAssign<Who> for u32 {
+    fn bitor_assign(&mut self, rhs: Who) {
+        *self = *self | rhs;
+    }
+}