Implemented stdio functions

src/stdio/Cargo.toml

@@ -8,6 +8,10 @@ build = "build.rs"
 cbindgen = { path = "../../cbindgen" }
 
 [dependencies]
+compiler_builtins = { git = "https://github.com/rust-lang-nursery/compiler-builtins.git", default-features = false, features = ["mem"] }
 platform = { path = "../platform" }
 va_list = { path = "../../va_list", features = ["no_std"] }
+fcntl = { path = "../fcntl" }
+string = { path = "../string" }
+stdlib = { path = "../stdlib" }
 errno = { path = "../errno"}

src/stdio/src/constants.rs

@@ -0,0 +1,27 @@
+use platform::types::*;
+
+pub const BUFSIZ: size_t = 1024;
+
+pub const UNGET: size_t = 8;
+
+pub const FILENAME_MAX: c_int = 4096;
+
+pub const F_PERM: c_int = 1;
+pub const F_NORD: c_int = 4;
+pub const F_NOWR: c_int = 8;
+pub const F_EOF: c_int = 16;
+pub const F_ERR: c_int = 32;
+pub const F_SVB: c_int = 64;
+pub const F_APP: c_int = 128;
+pub const F_BADJ: c_int = 256;
+
+pub const SEEK_SET: c_int = 0;
+pub const SEEK_CUR: c_int = 1;
+pub const SEEK_END: c_int = 2;
+
+pub const _IOFBF: c_int = 0;
+pub const _IOLBF: c_int = 1;
+pub const _IONBF: c_int = 2;
+
+#[allow(non_camel_case_types)]
+pub type fpos_t = off_t;

src/stdio/src/default.rs

@@ -0,0 +1,85 @@
+use core::sync::atomic::AtomicBool;
+use core::ptr;
+use super::{internal, BUFSIZ, FILE, UNGET, constants};
+
+#[allow(non_upper_case_globals)]
+static mut default_stdin_buf: [u8; BUFSIZ as usize + UNGET] = [0; BUFSIZ as usize + UNGET];
+
+#[allow(non_upper_case_globals)]
+static mut default_stdin: FILE = FILE {
+    flags: constants::F_PERM | constants::F_NOWR | constants::F_BADJ,
+    rpos: ptr::null_mut(),
+    rend: ptr::null_mut(),
+    wend: ptr::null_mut(),
+    wpos: ptr::null_mut(),
+    wbase: ptr::null_mut(),
+    fd: 0,
+    buf: unsafe { &mut default_stdin_buf as *mut [u8] as *mut u8 },
+    buf_size: BUFSIZ as usize,
+    buf_char: -1,
+    unget: UNGET,
+    lock: AtomicBool::new(false),
+    write: None,
+    read: Some(&internal::stdio_read),
+    seek: None,
+};
+
+#[allow(non_upper_case_globals)]
+static mut default_stdout_buf: [u8; BUFSIZ as usize] = [0; BUFSIZ as usize];
+
+#[allow(non_upper_case_globals)]
+static mut default_stdout: FILE = FILE {
+    flags: constants::F_PERM | constants::F_NORD | constants::F_BADJ,
+    rpos: ptr::null_mut(),
+    rend: ptr::null_mut(),
+    wend: ptr::null_mut(),
+    wpos: ptr::null_mut(),
+    wbase: ptr::null_mut(),
+    fd: 1,
+    buf: unsafe { &mut default_stdout_buf } as *mut [u8] as *mut u8,
+    buf_size: BUFSIZ as usize,
+    buf_char: b'\n' as i8,
+    unget: 0,
+    lock: AtomicBool::new(false),
+    write: Some(&internal::stdio_write),
+    read: None,
+    seek: None,
+};
+
+#[allow(non_upper_case_globals)]
+static mut default_stderr_buf: [u8; BUFSIZ as usize] = [0; BUFSIZ as usize];
+
+#[allow(non_upper_case_globals)]
+static mut default_stderr: FILE = FILE {
+    flags: constants::F_PERM | constants::F_NORD | constants::F_BADJ,
+    rpos: ptr::null_mut(),
+    rend: ptr::null_mut(),
+    wend: ptr::null_mut(),
+    wpos: ptr::null_mut(),
+    wbase: ptr::null_mut(),
+    fd: 2,
+    buf: unsafe { &mut default_stderr_buf } as *mut [u8] as *mut u8,
+    buf_size: BUFSIZ as usize,
+    buf_char: -1,
+    unget: 0,
+    lock: AtomicBool::new(false),
+    write: Some(&internal::stdio_write),
+    read: None,
+    seek: None,
+};
+
+// Don't ask me how the casting below works, I have no idea
+// " as *const FILE as *mut FILE" rust pls
+//
+// -- Tommoa
+#[allow(non_upper_case_globals)]
+#[no_mangle]
+pub static mut stdin: *mut FILE = unsafe { &default_stdin } as *const FILE as *mut FILE;
+
+#[allow(non_upper_case_globals)]
+#[no_mangle]
+pub static mut stdout: *mut FILE = unsafe { &default_stdout } as *const FILE as *mut FILE;
+
+#[allow(non_upper_case_globals)]
+#[no_mangle]
+pub static mut stderr: *mut FILE = unsafe { &default_stderr } as *const FILE as *mut FILE;

src/stdio/src/helpers.rs

@@ -0,0 +1,159 @@
+use super::{internal, BUFSIZ, FILE, UNGET};
+use compiler_builtins::mem::memset;
+use stdlib::calloc;
+use core::{mem, ptr};
+use core::sync::atomic::AtomicBool;
+use platform::types::*;
+use super::constants::*;
+use fcntl::*;
+use platform;
+use errno;
+
+/// Parse mode flags as a string and output a mode flags integer
+pub unsafe fn parse_mode_flags(mode_str: *const c_char) -> i32 {
+    use string::strchr;
+    let mut flags = if !strchr(mode_str, b'+' as i32).is_null() {
+        O_RDWR
+    } else if (*mode_str) == b'r' as i8 {
+        O_RDONLY
+    } else {
+        O_WRONLY
+    };
+    if !strchr(mode_str, b'x' as i32).is_null() {
+        flags |= O_EXCL;
+    }
+    if !strchr(mode_str, b'e' as i32).is_null() {
+        flags |= O_CLOEXEC;
+    }
+    if (*mode_str) != b'r' as i8 {
+        flags |= O_CREAT;
+    }
+    if (*mode_str) == b'w' as i8 {
+        flags |= O_TRUNC;
+    }
+    if (*mode_str) != b'a' as i8 {
+       flags |= O_APPEND;
+    }
+
+    flags
+}
+
+/// Open a file with the file descriptor `fd` in the mode `mode`
+pub unsafe fn _fdopen(fd: c_int, mode: *const c_char) -> *mut FILE {
+    use string::strchr;
+    if *mode != b'r' as i8 && *mode != b'w' as i8 && *mode != b'a' as i8 {
+        platform::errno = errno::EINVAL;
+        return ptr::null_mut();
+    }
+
+    let mut flags = 0;
+    if strchr(mode, b'+' as i32).is_null() {
+        flags |= if *mode == b'r' as i8 { F_NOWR } else { F_NORD };
+    }
+
+    if !strchr(mode, b'e' as i32).is_null() {
+        sys_fcntl(fd, F_SETFD, FD_CLOEXEC);
+    }
+
+    if *mode == 'a' as i8 {
+        let f = sys_fcntl(fd, F_GETFL, 0);
+        if (f & O_APPEND) == 0 {
+            sys_fcntl(fd, F_SETFL, f | O_APPEND);
+        }
+        flags |= F_APP;
+    }
+
+    let file = calloc(mem::size_of::<FILE>() + BUFSIZ + UNGET, 1) as *mut FILE;
+    // Allocate the file
+    (*file) = FILE {
+        flags: flags,
+        rpos: ptr::null_mut(),
+        rend: ptr::null_mut(),
+        wend: ptr::null_mut(),
+        wpos: ptr::null_mut(),
+        wbase: ptr::null_mut(),
+        fd: fd,
+        buf: (file as *mut u8).add(mem::size_of::<FILE>() + UNGET),
+        buf_size: BUFSIZ,
+        buf_char: -1,
+        unget: UNGET,
+        lock: AtomicBool::new(false),
+        write: Some(&internal::stdio_write),
+        read: Some(&internal::stdio_read),
+        seek: Some(&internal::stdio_seek),
+    };
+    file
+}
+
+/// Write buffer `buf` of length `l` into `stream`
+pub unsafe fn fwritex(buf: *const u8, l: size_t, stream: *mut FILE) -> size_t {
+    use compiler_builtins::mem::memcpy;
+    let mut buf = buf;
+    let mut l = l;
+    if let Some(stream_write) = (*stream).write {
+        if (*stream).wend.is_null() && !internal::to_write(stream) {
+            // We can't write to this stream
+            return 0;
+        }
+        if l > (*stream).wend as usize - (*stream).wpos as usize {
+            // We can't fit all of buf in the buffer
+            return (*stream_write)(stream, buf, l);
+        }
+
+        let i = if (*stream).buf_char >= 0 {
+            let mut i = l;
+            while i > 0 && *buf.offset(i as isize - 1) != b'\n' {
+                i -= 1;
+            }
+            if i > 0 {
+                let n = (*stream_write)(stream, buf, i);
+                if n < i {
+                    return n;
+                }
+                buf = buf.add(i);
+                l -= i;
+            }
+            i
+        } else {
+            0
+        };
+
+        memcpy((*stream).wpos, buf, l);
+        (*stream).wpos = (*stream).wpos.add(l);
+        l + i
+    } else {
+        // We can't write to this stream
+        0
+    }
+}
+
+/// Flush `stream` without locking it.
+pub unsafe fn fflush_unlocked(stream: *mut FILE) -> c_int {
+    if (*stream).wpos > (*stream).wbase {
+        if let Some(f) = (*stream).write {
+            (*f)(stream, ptr::null(), 0);
+            if (*stream).wpos.is_null() {
+                return -1;
+            }
+        } else {
+            return -1;
+        }
+    }
+
+    if (*stream).rpos < (*stream).rend {
+        if let Some(s) = (*stream).seek {
+            (*s)(
+                stream,
+                (*stream).rpos as i64 - (*stream).rend as i64,
+                SEEK_CUR,
+            );
+        }
+    }
+
+    (*stream).wpos = ptr::null_mut();
+    (*stream).wend = ptr::null_mut();
+    (*stream).wbase = ptr::null_mut();
+    (*stream).rpos = ptr::null_mut();
+    (*stream).rend = ptr::null_mut();
+    0
+}

src/stdio/src/internal.rs

@@ -0,0 +1,143 @@
+use super::{FILE, constants};
+use platform;
+use platform::types::*;
+use core::{mem, ptr, slice};
+
+pub fn stdio_read(stream: *mut FILE, buf: *mut u8, size: usize) -> usize {
+    unsafe {
+        let mut buff = slice::from_raw_parts_mut(buf, size - !((*stream).buf_size == 0) as usize);
+        let mut file_buf = slice::from_raw_parts_mut((*stream).buf, (*stream).buf_size);
+        let mut file = platform::FileReader((*stream).fd);
+        let count = if buff.len() == 0 {
+            file.read(&mut file_buf)
+        } else {
+            file.read(&mut buff) + file.read(&mut file_buf)
+        };
+        mem::forget(buff);
+        mem::forget(file_buf);
+        if count <= 0 {
+            (*stream).flags |= if count == 0 { constants::F_EOF } else { constants::F_ERR };
+            return 0;
+        }
+        if count as usize <= size {
+            return count as usize;
+        }
+        (*stream).rpos = (*stream).buf;
+        (*stream).rend = (*stream).buf.offset(count);
+        *buf.offset(size as isize - 1) = *(*stream).rpos;
+        (*stream).rpos = (*stream).rpos.add(1);
+    }
+    size
+}
+
+pub fn stdio_write(stream: *mut FILE, buf: *const u8, size: usize) -> usize {
+    unsafe {
+        let len = (*stream).wpos as usize - (*stream).wbase as usize;
+        let mut advance = 0;
+        let mut f_buf = slice::from_raw_parts((*stream).wbase, len);
+        let mut buff = slice::from_raw_parts(buf, size);
+        let mut f_filled = false;
+        let mut rem = f_buf.len() + buff.len();
+        let mut file = platform::FileWriter((*stream).fd);
+        loop {
+            let mut count = if f_filled {
+                file.write(&f_buf[advance..])
+            } else {
+                file.write(&f_buf[advance..]) + file.write(buff)
+            };
+            if count == rem as isize {
+                (*stream).wend = (*stream).buf.add((*stream).buf_size -1);
+                (*stream).wpos = (*stream).buf;
+                (*stream).wbase = (*stream).buf;
+                return size;
+            }
+            if count < 0 {
+                (*stream).wpos = ptr::null_mut();
+                (*stream).wbase = ptr::null_mut();
+                (*stream).wend = ptr::null_mut();
+                (*stream).flags |= constants::F_ERR;
+                return 0;
+            }
+            rem -= count as usize;
+            if count as usize > len {
+                count -= len as isize;
+                f_buf = buff;
+                f_filled = true;
+                advance = 0;
+            }
+            advance += count as usize;
+        }
+    }
+}
+
+pub unsafe fn to_read(stream: *mut FILE) -> bool {
+    if (*stream).flags & constants::F_BADJ > 0 {
+        // Static and needs unget region
+        (*stream).buf = (*stream).buf.add((*stream).unget);
+        (*stream).flags &= !constants::F_BADJ;
+    }
+
+    if (*stream).wpos > (*stream).wbase {
+        if let Some(f) = (*stream).write {
+            (*f)(stream, ptr::null(), 0);
+        }
+    }
+    (*stream).wpos = ptr::null_mut();
+    (*stream).wbase = ptr::null_mut();
+    (*stream).wend = ptr::null_mut();
+    if (*stream).flags & constants::F_NORD > 0 {
+        (*stream).flags |= constants::F_ERR;
+        return true;
+    }
+    (*stream).rpos = (*stream).buf.offset((*stream).buf_size as isize -1);
+    (*stream).rend = (*stream).buf.offset((*stream).buf_size as isize -1);
+    if (*stream).flags & constants::F_EOF > 0 {
+        true
+    } else {
+        false
+    }
+}
+
+pub unsafe fn to_write(stream: *mut FILE) -> bool {
+    if (*stream).flags & constants::F_BADJ > 0 {
+        // Static and needs unget region
+        (*stream).buf = (*stream).buf.add((*stream).unget);
+        (*stream).flags &= !constants::F_BADJ;
+    }
+
+    if (*stream).flags & constants::F_NOWR > 0 {
+        (*stream).flags &= constants::F_ERR;
+        return false;
+    }
+    (*stream).rpos = ptr::null_mut();
+    (*stream).rend = ptr::null_mut();
+    (*stream).wpos = (*stream).buf;
+    (*stream).wbase = (*stream).buf;
+    (*stream).wend = (*stream).buf.offset((*stream).buf_size as isize -1);
+    return true;
+}
+
+pub unsafe fn ftello(stream: *mut FILE) -> off_t {
+    if let Some(s) = (*stream).seek {
+        let pos = (*s)(
+            stream,
+            0,
+            if ((*stream).flags & constants::F_APP > 0) && (*stream).wpos > (*stream).wbase {
+                constants::SEEK_END
+            } else {
+                constants::SEEK_CUR
+            },
+        );
+        if pos < 0 {
+            return pos;
+        }
+        pos - ((*stream).rend as i64 - (*stream).rpos as i64)
+            + ((*stream).wpos as i64 - (*stream).wbase as i64)
+    } else {
+        -1
+    }
+}
+
+pub fn stdio_seek(stream: *mut FILE, off: off_t, whence: c_int) -> off_t {
+    unsafe { platform::lseek((*stream).fd, off, whence) }
+}

src/stdio/src/lib.rs

@@ -1,41 +1,64 @@
 //! stdio implementation for Redox, following http://pubs.opengroup.org/onlinepubs/7908799/xsh/stdio.h.html
 
+#![feature(compiler_builtins_lib)]
 #![no_std]
 
+extern crate compiler_builtins;
 extern crate errno;
+extern crate fcntl;
 extern crate platform;
+extern crate stdlib;
+extern crate string;
 extern crate va_list as vl;
 
 use core::str;
+use core::ptr;
 use core::fmt::Write;
+use core::sync::atomic::{AtomicBool, Ordering};
 
 use platform::types::*;
-use platform::c_str;
-use platform::errno;
+use platform::{c_str, errno};
 use errno::STR_ERROR;
 use vl::VaList as va_list;
 
 mod printf;
 
-pub const BUFSIZ: c_int = 4096;
+mod default;
+pub use default::*;
 
-pub const FILENAME_MAX: c_int = 4096;
+mod constants;
+pub use constants::*;
 
-pub type fpos_t = off_t;
+mod helpers;
 
-pub struct FILE;
+mod internal;
 
-#[allow(non_upper_case_globals)]
+/// The structure of this struct is likely to change.
+/// all of the _pos pointers are likely to change to isize offsets and its possible that the
+/// function pointers will be removed
+#[repr(C)]
+pub struct FILE {
+    flags: c_int,
+    rpos: *mut u8,
+    rend: *mut u8,
+    wend: *mut u8,
+    wpos: *mut u8,
+    wbase: *mut u8,
+    fd: c_int,
+    buf: *mut u8,
+    buf_size: size_t,
+    buf_char: i8,
+    lock: AtomicBool,
+    unget: size_t,
+    write: Option<*const (Fn(*mut FILE, *const u8, usize) -> size_t)>,
+    read: Option<*const (Fn(*mut FILE, *mut u8, usize) -> size_t)>,
+    seek: Option<*const (Fn(*mut FILE, off_t, c_int) -> off_t)>,
+}
+
+/// Clears EOF and ERR indicators on a stream
 #[no_mangle]
-pub static mut stdout: *mut FILE = 1 as *mut FILE;
-
-#[allow(non_upper_case_globals)]
-#[no_mangle]
-pub static mut stderr: *mut FILE = 2 as *mut FILE;
-
-#[no_mangle]
-pub extern "C" fn clearerr(stream: *mut FILE) {
-    unimplemented!();
+pub unsafe extern "C" fn clearerr(stream: *mut FILE) {
+    (*stream).flags &= !(F_EOF & F_ERR);
 }
 
 #[no_mangle]
@@ -48,88 +71,244 @@ pub extern "C" fn cuserid(s: *mut c_char) -> *mut c_char {
     unimplemented!();
 }
 
+/// Close a file
+/// This function does not guarentee that the file buffer will be flushed or that the file
+/// descriptor will be closed, so if it is important that the file be written to, use `fflush()`
+/// prior to using this function.
 #[no_mangle]
-pub extern "C" fn fclose(stream: *mut FILE) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn fclose(stream: *mut FILE) -> c_int {
+    use stdlib::free;
+    flockfile(stream);
+    let r = helpers::fflush_unlocked(stream) | platform::close((*stream).fd);
+    if (*stream).flags & constants::F_PERM == 0 { 
+        // Not one of stdin, stdout or stderr
+        free(stream as *mut _);
+    }
+    r
 }
 
+/// Open a file from a file descriptor
 #[no_mangle]
-pub extern "C" fn fdopen(fildes: c_int, mode: *const c_char) -> *mut FILE {
-    unimplemented!();
+pub unsafe extern "C" fn fdopen(fildes: c_int, mode: *const c_char) -> *mut FILE {
+    helpers::_fdopen(fildes, mode)
 }
 
+/// Check for EOF
 #[no_mangle]
-pub extern "C" fn feof(stream: *mut FILE) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn feof(stream: *mut FILE) -> c_int {
+    flockfile(stream);
+    let ret = (*stream).flags & F_EOF;
+    funlockfile(stream);
+    ret
 }
 
+/// Check for ERR
 #[no_mangle]
-pub extern "C" fn ferror(stream: *mut FILE) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn ferror(stream: *mut FILE) -> c_int {
+    flockfile(stream);
+    let ret = (*stream).flags & F_ERR;
+    funlockfile(stream);
+    ret
 }
 
+/// Flush output to stream, or sync read position
+/// Ensure the file is unlocked before calling this function, as it will attempt to lock the file
+/// itself.
 #[no_mangle]
-pub extern "C" fn fflush(stream: *mut FILE) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn fflush(stream: *mut FILE) -> c_int {
+    flockfile(stream);
+
+    let ret = helpers::fflush_unlocked(stream);
+
+    funlockfile(stream);
+    ret
 }
 
+/// Get a single char from a stream
 #[no_mangle]
-pub extern "C" fn fgetc(stream: *mut FILE) -> c_int {
-    unimplemented!();
-}
-
-#[no_mangle]
-pub extern "C" fn fgetpos(stream: *mut FILE, pos: *mut fpos_t) -> c_int {
-    unimplemented!();
-}
-
-#[no_mangle]
-pub extern "C" fn fgets(s: *mut c_char, n: c_int, stream: *mut FILE) -> *mut c_char {
-    unimplemented!();
-}
-
-#[no_mangle]
-pub extern "C" fn fileno(stream: *mut FILE) -> c_int {
-    unimplemented!();
-}
-
-#[no_mangle]
-pub extern "C" fn flockfile(file: *mut FILE) {
-    unimplemented!();
-}
-
-#[no_mangle]
-pub extern "C" fn fopen(filename: *const c_char, mode: *const c_char) -> *mut FILE {
-    unimplemented!();
-}
-
-#[no_mangle]
-pub extern "C" fn fputc(c: c_int, stream: *mut FILE) -> c_int {
-    platform::FileWriter(stream as c_int)
-        .write_char(c as u8 as char)
-        .map_err(|_| return -1);
+pub unsafe extern "C" fn fgetc(stream: *mut FILE) -> c_int {
+    flockfile(stream);
+    let c = getc_unlocked(stream);
+    funlockfile(stream);
     c
 }
 
+/// Get the position of the stream and store it in pos
+#[no_mangle]
+pub unsafe extern "C" fn fgetpos(stream: *mut FILE, pos: *mut fpos_t) -> c_int {
+    let off = internal::ftello(stream);
+    if off < 0 {
+        return -1;
+    }
+    (*pos) = off;
+    0
+}
+
+/// Get a string from the stream
+#[no_mangle]
+pub unsafe extern "C" fn fgets(s: *mut c_char, n: c_int, stream: *mut FILE) -> *mut c_char {
+    use string::memchr;
+    use compiler_builtins::mem::memcpy;
+    flockfile(stream);
+    let mut ptr = s as *mut u8;
+    let mut n = n;
+    if n <= 1 {
+        funlockfile(stream);
+        if n == 0 {
+            return ptr::null_mut();
+        }
+        (*s) = b'\0' as i8;
+        return s;
+    }
+    while n > 0 {
+        let z = memchr(
+            (*stream).rpos as *const c_void,
+            b'\n' as c_int,
+            (*stream).rend as usize - (*stream).rpos as usize,
+        ) as *mut u8;
+        let k = if z.is_null() {
+            (*stream).rend as usize - (*stream).rpos as usize
+        } else {
+            z as usize - (*stream).rpos as usize + 1
+        };
+        let k = if k as i32 > n { n as usize } else { k };
+        memcpy(ptr, (*stream).rpos, k);
+        (*stream).rpos = (*stream).rpos.add(k);
+        ptr = ptr.add(k);
+        n -= k as i32;
+        if !z.is_null() || n < 1 {
+            break;
+        }
+        let c = getc_unlocked(stream);
+        if c < 0 {
+            break;
+        }
+        n -= 1;
+        *ptr = c as u8;
+        ptr = ptr.add(1);
+        if c as u8 == b'\n' {
+            break;
+        }
+    }
+    if !s.is_null() {
+        *ptr = 0;
+    }
+    funlockfile(stream);
+    s
+}
+
+/// Get the underlying file descriptor
+#[no_mangle]
+pub unsafe extern "C" fn fileno(stream: *mut FILE) -> c_int {
+    flockfile(stream);
+    funlockfile(stream);
+    (*stream).fd
+}
+
+/// Lock the file
+/// Do not call any functions other than those with the `_unlocked` postfix while the file is
+/// locked
+#[no_mangle]
+pub unsafe extern "C" fn flockfile(file: *mut FILE) {
+    while ftrylockfile(file) != 0 {}
+}
+
+/// Open the file in mode `mode`
+#[no_mangle]
+pub unsafe extern "C" fn fopen(filename: *const c_char, mode: *const c_char) -> *mut FILE {
+    use core::ptr;
+    let initial_mode = *mode;
+    if initial_mode != b'r' as i8 && initial_mode != b'w' as i8 && initial_mode != b'a' as i8 {
+        platform::errno = errno::EINVAL;
+        return ptr::null_mut();
+    }
+
+    let flags = helpers::parse_mode_flags(mode);
+
+    let fd = fcntl::sys_open(filename, flags, 0o666);
+    if fd < 0 {
+        return ptr::null_mut();
+    }
+
+    if flags & fcntl::O_CLOEXEC > 0 {
+        fcntl::sys_fcntl(fd, fcntl::F_SETFD, fcntl::FD_CLOEXEC);
+    }
+
+    let f = helpers::_fdopen(fd, mode); 
+    if f.is_null() {
+        platform::close(fd);
+        return ptr::null_mut();
+    }
+    f
+}
+
+/// Insert a character into the stream
+#[no_mangle]
+pub unsafe extern "C" fn fputc(c: c_int, stream: *mut FILE) -> c_int {
+    flockfile(stream);
+    let c = putc_unlocked(c, stream);
+    funlockfile(stream);
+    c
+}
+
+/// Insert a string into a stream
 #[no_mangle]
 pub unsafe extern "C" fn fputs(s: *const c_char, stream: *mut FILE) -> c_int {
     extern "C" {
         fn strlen(s: *const c_char) -> size_t;
     }
-    use core::{slice, str};
     let len = strlen(s);
-    platform::FileWriter(stream as c_int)
-        .write_str(str::from_utf8_unchecked(slice::from_raw_parts(
-            s as *const u8,
-            len,
-        )))
-        .map_err(|_| return -1);
-    len as i32
+    (fwrite(s as *const c_void, 1, len, stream) == len) as c_int - 1
 }
 
+/// Read `nitems` of size `size` into `ptr` from `stream`
 #[no_mangle]
-pub extern "C" fn fread(ptr: *mut c_void, size: usize, nitems: usize, stream: *mut FILE) -> usize {
-    unimplemented!();
+pub unsafe extern "C" fn fread(
+    ptr: *mut c_void,
+    size: usize,
+    nitems: usize,
+    stream: *mut FILE,
+) -> usize {
+    use compiler_builtins::mem::memcpy;
+    let mut dest = ptr as *mut u8;
+    let len = size * nitems;
+    let mut l = len as isize;
+
+    flockfile(stream);
+
+    if (*stream).rend > (*stream).rpos {
+        // We have some buffered data that can be read
+        let diff = (*stream).rend as usize - (*stream).rpos as usize;
+        let k = if diff < l as usize { diff } else { l as usize };
+        memcpy(dest, (*stream).rpos, k);
+        (*stream).rpos = (*stream).rpos.add(k);
+        dest = dest.add(k);
+        l -= k as isize;
+    }
+
+    while l > 0 {
+        let k = if internal::to_read(stream) {
+            0
+        } else {
+            if let Some(f) = (*stream).read {
+                (*f)(stream, dest, l as usize)
+            }
+            else {
+                0
+            }
+        };
+
+        if k == 0 {
+            funlockfile(stream);
+            return (len - l as usize) / 2;
+        }
+
+        l -= k as isize;
+        dest = dest.add(k);
+    }
+
+    funlockfile(stream);
+    nitems
 }
 
 #[no_mangle]
@@ -141,79 +320,169 @@ pub extern "C" fn freopen(
     unimplemented!();
 }
 
+/// Seek to an offset `offset` from `whence`
 #[no_mangle]
-pub extern "C" fn fseek(stream: *mut FILE, offset: c_long, whence: c_int) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn fseek(stream: *mut FILE, offset: c_long, whence: c_int) -> c_int {
+    if fseeko(stream, offset as off_t, whence) != -1 {
+        return 0;
+    }
+    -1
 }
 
+/// Seek to an offset `offset` from `whence`
 #[no_mangle]
-pub extern "C" fn fseeko(stream: *mut FILE, offset: off_t, whence: c_int) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn fseeko(stream: *mut FILE, offset: off_t, whence: c_int) -> c_int {
+    let mut off = offset;
+    flockfile(stream);
+    // Adjust for what is currently in the buffer
+    if whence == SEEK_CUR {
+        off -= ((*stream).rend as usize - (*stream).rpos as usize) as i64;
+    }
+    if (*stream).wpos > (*stream).wbase {
+        if let Some(f) = (*stream).write {
+            (*f)(stream, ptr::null(), 0);
+            if (*stream).wpos.is_null() {
+                return -1;
+            }
+        }
+    }
+    (*stream).wpos = ptr::null_mut();
+    (*stream).wend = ptr::null_mut();
+    (*stream).wbase = ptr::null_mut();
+    if let Some(s) = (*stream).seek {
+        if (*s)(stream, off, whence) < 0 {
+            return -1;
+        }
+    } else {
+        return -1;
+    }
+    (*stream).rpos = ptr::null_mut();
+    (*stream).rend = ptr::null_mut();
+    (*stream).flags &= !F_EOF;
+    funlockfile(stream);
+    0
 }
 
+/// Seek to a position `pos` in the file from the beginning of the file
 #[no_mangle]
-pub extern "C" fn fsetpos(stream: *mut FILE, pos: *const fpos_t) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn fsetpos(stream: *mut FILE, pos: *const fpos_t) -> c_int {
+    fseek(stream, *pos as off_t, SEEK_SET)
 }
 
+/// Get the current position of the cursor in the file
 #[no_mangle]
-pub extern "C" fn ftell(stream: *mut FILE) -> c_long {
-    unimplemented!();
+pub unsafe extern "C" fn ftell(stream: *mut FILE) -> c_long {
+    ftello(stream) as c_long
 }
 
+/// Get the current position of the cursor in the file
 #[no_mangle]
-pub extern "C" fn ftello(stream: *mut FILE) -> off_t {
-    unimplemented!();
+pub unsafe extern "C" fn ftello(stream: *mut FILE) -> off_t {
+    flockfile(stream);
+    let pos = internal::ftello(stream);
+    funlockfile(stream);
+    pos
 }
 
+/// Try to lock the file. Returns 0 for success, 1 for failure
 #[no_mangle]
-pub extern "C" fn ftrylockfile(file: *mut FILE) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn ftrylockfile(file: *mut FILE) -> c_int {
+    (*file)
+        .lock
+        .compare_and_swap(false, true, Ordering::Acquire) as c_int
 }
 
+/// Unlock the file
 #[no_mangle]
-pub extern "C" fn funlockfile(file: *mut FILE) {
-    unimplemented!();
+pub unsafe extern "C" fn funlockfile(file: *mut FILE) {
+    (*file).lock.store(false, Ordering::Release);
 }
 
+/// Write `nitems` of size `size` from `ptr` to `stream`
 #[no_mangle]
-pub extern "C" fn fwrite(
+pub unsafe extern "C" fn fwrite(
     ptr: *const c_void,
     size: usize,
     nitems: usize,
     stream: *mut FILE,
 ) -> usize {
-    unimplemented!();
+    let l = size * nitems;
+    let nitems = if size == 0 { 0 } else { nitems };
+    flockfile(stream);
+    let k = helpers::fwritex(ptr as *const u8, l, stream);
+    funlockfile(stream);
+    if k == l {
+        nitems
+    } else {
+        k / size
+    }
 }
 
+/// Get a single char from a stream
 #[no_mangle]
-pub extern "C" fn getc(stream: *mut FILE) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn getc(stream: *mut FILE) -> c_int {
+    flockfile(stream);
+    let c = getc_unlocked(stream);
+    funlockfile(stream);
+    c
 }
 
+/// Get a single char from `stdin`
 #[no_mangle]
-pub extern "C" fn getchar() -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn getchar() -> c_int {
+    fgetc(stdin)
 }
 
+/// Get a char from a stream without locking the stream
 #[no_mangle]
-pub extern "C" fn getc_unlocked(stream: *mut FILE) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn getc_unlocked(stream: *mut FILE) -> c_int {
+    if (*stream).rpos < (*stream).rend {
+        let ret = *(*stream).rpos as c_int;
+        (*stream).rpos = (*stream).rpos.add(1);
+        ret
+    } else {
+        if let Some(read) = (*stream).read {
+            let mut c = 0u8;
+            if !internal::to_read(stream) && (*read)(stream, &mut c, 1) == 1 {
+                c as c_int
+            } else {
+                -1
+            }
+        } else {
+            -1
+        }
+    }
 }
 
+/// Get a char from `stdin` without locking `stdin`
 #[no_mangle]
-pub extern "C" fn getchar_unlocked() -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn getchar_unlocked() -> c_int {
+    getc_unlocked(stdin)
 }
 
+/// Get a string from `stdin`
 #[no_mangle]
-pub extern "C" fn gets(s: *mut c_char) -> *mut c_char {
-    unimplemented!();
+pub unsafe extern "C" fn gets(s: *mut c_char) -> *mut c_char {
+    use core::i32;
+    fgets(s, i32::MAX, stdin)
 }
 
+/// Get an integer from `stream`
 #[no_mangle]
-pub extern "C" fn getw(stream: *mut FILE) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn getw(stream: *mut FILE) -> c_int {
+    use core::mem;
+    let mut ret: c_int = 0;
+    if fread(
+        &mut ret as *mut c_int as *mut c_void,
+        mem::size_of_val(&ret),
+        1,
+        stream,
+    ) > 0
+    {
+        ret
+    } else {
+        -1
+    }
 }
 
 #[no_mangle]
@@ -238,60 +507,134 @@ pub extern "C" fn popen(command: *const c_char, mode: *const c_char) -> *mut FIL
     unimplemented!();
 }
 
+/// Put a character `c` into `stream`
 #[no_mangle]
-pub extern "C" fn putc(c: c_int, stream: *mut FILE) -> c_int {
-    fputc(c, stream)
+pub unsafe extern "C" fn putc(c: c_int, stream: *mut FILE) -> c_int {
+    flockfile(stream);
+    let ret = putc_unlocked(c, stream);
+    funlockfile(stream);
+    ret
 }
 
+/// Put a character `c` into `stdout`
 #[no_mangle]
 pub unsafe extern "C" fn putchar(c: c_int) -> c_int {
-    putc(c, stdout)
+    fputc(c, stdout)
 }
 
+/// Put a character `c` into `stream` without locking `stream`
 #[no_mangle]
-pub extern "C" fn putc_unlocked(c: c_int, stream: *mut FILE) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn putc_unlocked(c: c_int, stream: *mut FILE) -> c_int {
+    if c as i8 != (*stream).buf_char && (*stream).wpos < (*stream).wend {
+        *(*stream).wpos = c as u8;
+        (*stream).wpos = (*stream).wpos.add(1);
+        c
+    } else {
+        if let Some(write) = (*stream).write {
+            if (*stream).wend.is_null() && internal::to_write(stream) {
+                -1
+            } else if c as i8 != (*stream).buf_char && (*stream).wpos < (*stream).wend {
+                *(*stream).wpos = c as u8;
+                (*stream).wpos = (*stream).wpos.add(1);
+                c
+            } else if (*write)(stream, &c as *const i32 as *const _, 1) != 1 {
+                -1
+            } else {
+                c
+            }
+        } else {
+            -1
+        }
+    }
 }
 
+/// Put a character `c` into `stdout` without locking `stdout`
 #[no_mangle]
 pub unsafe extern "C" fn putchar_unlocked(c: c_int) -> c_int {
     putc_unlocked(c, stdout)
 }
 
+/// Put a string `s` into `stdout`
 #[no_mangle]
 pub unsafe extern "C" fn puts(s: *const c_char) -> c_int {
-    fputs(s, stdout);
-    putchar(b'\n' as c_int)
+    let ret = (fputs(s, stdout) > 0) || (putchar_unlocked(b'\n' as c_int) > 0);
+    if ret {
+        0
+    } else {
+        -1
+    }
 }
 
+/// Put an integer `w` into `stream`
 #[no_mangle]
-pub extern "C" fn putw(w: c_int, stream: *mut FILE) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn putw(w: c_int, stream: *mut FILE) -> c_int {
+    use core::mem;
+    fwrite(&w as *const i32 as _, mem::size_of_val(&w), 1, stream) as i32 - 1
 }
 
+/// Delete file or directory `path`
 #[no_mangle]
 pub extern "C" fn remove(path: *const c_char) -> c_int {
-    unimplemented!();
+    let r = platform::unlink(path);
+    if r == -errno::EISDIR {
+        platform::rmdir(path)
+    } else {
+        r
+    }
 }
 
 #[no_mangle]
 pub extern "C" fn rename(old: *const c_char, new: *const c_char) -> c_int {
+    // This function requires a rename syscall, which currently is not in platform.
     unimplemented!();
 }
 
+/// Rewind `stream` back to the beginning of it
 #[no_mangle]
-pub extern "C" fn rewind(stream: *mut FILE) {
-    unimplemented!();
+pub unsafe extern "C" fn rewind(stream: *mut FILE) {
+    fseeko(stream, 0, SEEK_SET);
+    flockfile(stream);
+    (*stream).flags &= !F_ERR;
+    funlockfile(stream);
 }
 
+/// Reset `stream` to use buffer `buf`. Buffer must be `BUFSIZ` in length
 #[no_mangle]
 pub extern "C" fn setbuf(stream: *mut FILE, buf: *mut c_char) {
-    unimplemented!();
+    unsafe {
+        setvbuf(
+            stream,
+            buf,
+            if buf.is_null() { _IONBF } else { _IOFBF },
+            BUFSIZ as usize,
+        )
+    };
 }
 
+/// Reset `stream` to use buffer `buf` of size `size`
 #[no_mangle]
-pub extern "C" fn setvbuf(stream: *mut FILE, buf: *mut c_char, mode: c_int, size: usize) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn setvbuf(
+    stream: *mut FILE,
+    buf: *mut c_char,
+    mode: c_int,
+    size: usize,
+) -> c_int {
+    // TODO: Check correctness
+    use stdlib::calloc;
+    let mut buf = buf;
+    if buf.is_null() && mode != _IONBF {
+        buf = calloc(size, 1) as *mut c_char;
+    }
+    (*stream).buf_size = size;
+    (*stream).buf_char = -1;
+    if mode == _IONBF {
+        (*stream).buf_size = 0;
+    } else if mode == _IOLBF {
+        (*stream).buf_char = b'\n' as i8;
+    }
+    (*stream).flags |= F_SVB;
+    (*stream).buf = buf as *mut u8;
+    0
 }
 
 #[no_mangle]
@@ -309,14 +652,35 @@ pub extern "C" fn tmpnam(s: *mut c_char) -> *mut c_char {
     unimplemented!();
 }
 
+/// Push character `c` back onto `stream` so it'll be read next
 #[no_mangle]
-pub extern "C" fn ungetc(c: c_int, stream: *mut FILE) -> c_int {
-    unimplemented!();
+pub unsafe extern "C" fn ungetc(c: c_int, stream: *mut FILE) -> c_int {
+    if c < 0 {
+        c
+    } else {
+        flockfile(stream);
+        if (*stream).rpos.is_null() {
+            internal::to_read(stream);
+        }
+        if (*stream).rpos.is_null()
+            || (*stream).rpos <= (*stream).buf.sub((*stream).unget)
+        {
+            funlockfile(stream);
+            return -1;
+        }
+
+        (*stream).rpos = (*stream).rpos.sub(1);
+        *(*stream).rpos = c as u8;
+        (*stream).flags &= !F_EOF;
+
+        funlockfile(stream);
+        c
+    }
 }
 
 #[no_mangle]
 pub unsafe extern "C" fn vfprintf(file: *mut FILE, format: *const c_char, ap: va_list) -> c_int {
-    printf::printf(platform::FileWriter(file as c_int), format, ap)
+    printf::printf(platform::FileWriter((*file).fd), format, ap)
 }
 
 #[no_mangle]