rust/src/libcore/os.rs

// Higher-level interfaces to libc::* functions and operating system services.
//
// In general these take and return rust types, use rust idioms (enums,
// closures, vectors) rather than C idioms, and do more extensive safety
// checks.
//
// This module is not meant to only contain 1:1 mappings to libc entries; any
// os-interface code that is reasonably useful and broadly applicable can go
// here. Including utility routines that merely build on other os code.
//
// We assume the general case is that users do not care, and do not want to
// be made to care, which operating system they are on. While they may want
// to special case various special cases -- and so we will not _hide_ the
// facts of which OS the user is on -- they should be given the opportunity
// to write OS-ignorant code by default.

import libc::{c_char, c_void, c_int, c_uint, size_t, ssize_t,
              mode_t, pid_t, FILE};
import libc::{close, fclose};

import option::{some, none};
import option = option::t;

import getcwd = rustrt::rust_getcwd;
import consts::*;

export close, fclose, fsync_fd;
export env, getenv, setenv, fdopen, pipe;
export getcwd, dll_filename, self_exe_path;
export exe_suffix, dll_suffix, sysname;
export homedir, list_dir, path_is_dir, path_exists;

native mod rustrt {
    fn rust_env_pairs() -> [str];
    fn rust_getcwd() -> str;
    fn rust_path_is_dir(path: str::sbuf) -> c_int;
    fn rust_path_exists(path: str::sbuf) -> c_int;
    fn rust_list_files(path: str) -> [str];
    fn rust_process_wait(handle: c_int) -> c_int;
}


fn env() -> [(str,str)] {
    let mut pairs = [];
    for p in rustrt::rust_env_pairs() {
        let vs = str::splitn_char(p, '=', 1u);
        assert vec::len(vs) == 2u;
        pairs += [(vs[0], vs[1])];
    }
    ret pairs;
}

const tmpbuf_sz : uint = 1000u;

fn as_c_charp<T>(s: str, f: fn(*c_char) -> T) -> T {
    str::as_buf(s) {|b| f(b as *c_char) }
}

fn fill_charp_buf(f: fn(*mutable c_char, size_t) -> bool)
    -> option<str> {
    let buf = vec::to_mut(vec::init_elt(tmpbuf_sz, 0u8 as c_char));
    vec::as_mut_buf(buf) { |b|
        if f(b, tmpbuf_sz as size_t) {
            some(str::from_cstr(b as str::sbuf))
        } else {
            none
        }
    }
}

#[cfg(target_os = "win32")]
mod win32 {
    import dword = libc::types::os::arch::extra::DWORD;

    fn fill_utf16_buf_and_decode(f: fn(*mutable u16, dword) -> dword)
        -> option<str> {
        let buf = vec::to_mut(vec::init_elt(tmpbuf_sz, 0u16));
        vec::as_mut_buf(buf) {|b|
            let k : dword = f(b, tmpbuf_sz as dword);
            if k == (0 as dword) {
                none
            } else {
                let sub = vec::slice(buf, 0u, k as uint);
                option::some::<str>(str::from_utf16(sub))
            }
        }
    }

    fn as_utf16_p<T>(s: str, f: fn(*u16) -> T) -> T {
        let mut t = str::to_utf16(s);
        // Null terminate before passing on.
        t += [0u16];
        vec::as_buf(t, f)
    }
}


#[cfg(target_os = "linux")]
#[cfg(target_os = "macos")]
#[cfg(target_os = "freebsd")]
fn getenv(n: str) -> option<str> unsafe {
    let s = as_c_charp(n, libc::getenv);
    ret if unsafe::reinterpret_cast(s) == 0 {
            option::none::<str>
        } else {
            let s = unsafe::reinterpret_cast(s);
            option::some::<str>(str::from_cstr(s))
        };
}

#[cfg(target_os = "win32")]
fn getenv(n: str) -> option<str> unsafe {
    import libc::types::os::arch::extra::*;
    import libc::funcs::extra::kernel32::*;
    import win32::*;
    as_utf16_p(n) {|u|
        fill_utf16_buf_and_decode() {|buf, sz|
            GetEnvironmentVariableW(u, buf, sz)
        }
    }
}


#[cfg(target_os = "linux")]
#[cfg(target_os = "macos")]
#[cfg(target_os = "freebsd")]
fn setenv(n: str, v: str) {

    // FIXME: remove this when export globs work properly.
    import libc::funcs::posix01::unistd::setenv;
    as_c_charp(n) {|nbuf|
        as_c_charp(v) {|vbuf|
            setenv(nbuf, vbuf, 1i32);
        }
    }
}


#[cfg(target_os = "win32")]
fn setenv(n: str, v: str) {
    // FIXME: remove imports when export globs work properly.
    import libc::funcs::extra::kernel32::*;
    import win32::*;
    as_utf16_p(n) {|nbuf|
        as_utf16_p(v) {|vbuf|
            SetEnvironmentVariableW(nbuf, vbuf);
        }
    }
}


fn fdopen(fd: c_int) -> *FILE {
    ret as_c_charp("r") {|modebuf|
        libc::fdopen(fd, modebuf)
    };
}


// fsync related

enum fsync_level {
    // whatever fsync does on that platform
    fsync,

    // fdatasync on linux, similiar or more on other platforms
    fdatasync,

    // full fsync
    //
    // You must additionally sync the parent directory as well!
    fullfsync,
}

#[cfg(target_os = "win32")]
fn fsync_fd(fd: c_int, _level: fsync_level) -> c_int {
    import libc::funcs::extra::msvcrt::*;
    ret commit(fd);
}

#[cfg(target_os = "linux")]
fn fsync_fd(fd: c_int, level: fsync_level) -> c_int {
    import libc::funcs::posix01::unistd::*;
    alt level {
      fsync | fullfsync { ret fsync(fd); }
      fdatasync { ret fdatasync(fd); }
    }
}

#[cfg(target_os = "macos")]
fn fsync_fd(fd: c_int, level: fsync_level) -> c_int {
    import libc::consts::os::extra::*;
    import libc::funcs::posix88::fcntl::*;
    import libc::funcs::posix01::unistd::*;
    alt level {
      fsync { ret fsync(fd); }
      _ {
        // According to man fnctl, the ok retval is only specified to be !=-1
        if (fcntl(F_FULLFSYNC as c_int, fd) == -1 as c_int)
            { ret -1 as c_int; }
        else
            { ret 0 as c_int; }
      }
    }
}

#[cfg(target_os = "freebsd")]
fn fsync_fd(fd: c_int, _l: fsync_level) -> c_int {
    import libc::funcs::posix01::unistd::*;
    ret fsync(fd);
}


#[cfg(target_os = "win32")]
fn waitpid(pid: pid_t) -> c_int {
    ret rustrt::rust_process_wait(pid);
}

#[cfg(target_os = "linux")]
#[cfg(target_os = "freebsd")]
#[cfg(target_os = "macos")]
fn waitpid(pid: pid_t) -> c_int {
    import libc::funcs::posix01::wait::*;
    let status = 0 as c_int;

    assert (waitpid(pid, ptr::mut_addr_of(status),
                    0 as c_int) != (-1 as c_int));
    ret status;
}


#[cfg(target_os = "linux")]
#[cfg(target_os = "freebsd")]
#[cfg(target_os = "macos")]
fn pipe() -> {in: c_int, out: c_int} {
    let fds = {mutable in: 0 as c_int,
               mutable out: 0 as c_int };
    assert (libc::pipe(ptr::mut_addr_of(fds.in)) == (0 as c_int));
    ret {in: fds.in, out: fds.out};
}



#[cfg(target_os = "win32")]
fn pipe() -> {in: c_int, out: c_int} {
    // FIXME: remove this when export globs work properly.
    import libc::consts::os::extra::*;
    // Windows pipes work subtly differently than unix pipes, and their
    // inheritance has to be handled in a different way that I do not fully
    // understand. Here we explicitly make the pipe non-inheritable, which
    // means to pass it to a subprocess they need to be duplicated first, as
    // in rust_run_program.
    let fds = { mutable in: 0 as c_int,
               mutable out: 0 as c_int };
    let res = libc::pipe(ptr::mut_addr_of(fds.in),
                         1024 as c_uint,
                         (O_BINARY | O_NOINHERIT) as c_int);
    assert (res == 0 as c_int);
    assert (fds.in != -1 as c_int && fds.in != 0 as c_int);
    assert (fds.out != -1 as c_int && fds.in != 0 as c_int);
    ret {in: fds.in, out: fds.out};
}


fn dll_filename(base: str) -> str {
    ret pre() + base + dll_suffix();

    #[cfg(target_os = "macos")]
    #[cfg(target_os = "linux")]
    #[cfg(target_os = "freebsd")]
    fn pre() -> str { "lib" }

    #[cfg(target_os = "win32")]
    fn pre() -> str { "" }
}


fn self_exe_path() -> option<path> {

    #[cfg(target_os = "freebsd")]
    fn load_self() -> option<path> unsafe {
        import libc::funcs::bsd44::*;
        import libc::consts::os::extra::*;
        fill_charp_buf() {|buf, sz|
            let mib = [CTL_KERN as c_int,
                       KERN_PROC as c_int,
                       KERN_PROC_PATHNAME as c_int, -1 as c_int];
            sysctl(vec::unsafe::to_ptr(mib), vec::len(mib) as c_uint,
                   buf as *mutable c_void, ptr::mut_addr_of(sz),
                   ptr::null(), 0u as size_t) != (0 as c_int)
        }
    }

    #[cfg(target_os = "linux")]
    fn load_self() -> option<path> unsafe {
        import libc::funcs::posix01::unistd::readlink;
        fill_charp_buf() {|buf, sz|
            as_c_charp("/proc/self/exe") { |proc_self_buf|
                readlink(proc_self_buf, buf, sz) != (-1 as ssize_t)
            }
        }
    }

    #[cfg(target_os = "macos")]
    fn load_self() -> option<path> unsafe {
        // FIXME: remove imports when export globs work properly.
        import libc::funcs::extra::*;
        fill_charp_buf() {|buf, sz|
            _NSGetExecutablePath(buf, ptr::mut_addr_of(sz as u32))
                == (0 as c_int)
        }
    }

    #[cfg(target_os = "win32")]
    fn load_self() -> option<path> unsafe {
        // FIXME: remove imports when export globs work properly.
        import libc::types::os::arch::extra::*;
        import libc::funcs::extra::kernel32::*;
        import win32::*;
        fill_utf16_buf_and_decode() {|buf, sz|
            GetModuleFileNameW(0u, buf, sz)
        }
    }

    option::map(load_self()) {|pth|
        path::dirname(pth) + path::path_sep()
    }
}


/*
Function: homedir

Returns the path to the user's home directory, if known.

On Unix, returns the value of the "HOME" environment variable if it is set and
not equal to the empty string.

On Windows, returns the value of the "HOME" environment variable if it is set
and not equal to the empty string. Otherwise, returns the value of the
"USERPROFILE" environment variable if it is set and not equal to the empty
string.

Otherwise, homedir returns option::none.
*/
fn homedir() -> option<path> {
    ret alt getenv("HOME") {
        some(p) {
            if !str::is_empty(p) {
                some(p)
            } else {
                secondary()
            }
        }
        none {
            secondary()
        }
    };

    #[cfg(target_os = "linux")]
    #[cfg(target_os = "macos")]
    #[cfg(target_os = "freebsd")]
    fn secondary() -> option<path> {
        none
    }

    #[cfg(target_os = "win32")]
    fn secondary() -> option<path> {
        option::maybe(none, getenv("USERPROFILE")) {|p|
            if !str::is_empty(p) {
                some(p)
            } else {
                none
            }
        }
    }
}



/*
Function: path_is_dir

Indicates whether a path represents a directory.
*/
fn path_is_dir(p: path) -> bool {
    str::as_buf(p) {|buf|
        rustrt::rust_path_is_dir(buf) != 0 as c_int
    }
}

/*
Function: path_exists

Indicates whether a path exists.
*/
fn path_exists(p: path) -> bool {
    str::as_buf(p) {|buf|
        rustrt::rust_path_exists(buf) != 0 as c_int
    }
}

// FIXME: under Windows, we should prepend the current drive letter to paths
// that start with a slash.
/*
Function: make_absolute

Convert a relative path to an absolute path

If the given path is relative, return it prepended with the current working
directory. If the given path is already an absolute path, return it
as is.
*/
// NB: this is here rather than in path because it is a form of environment
// querying; what it does depends on the process working directory, not just
// the input paths.
fn make_absolute(p: path) -> path {
    if path::path_is_absolute(p) {
        p
    } else {
        path::connect(getcwd(), p)
    }
}


/*
Function: make_dir

Creates a directory at the specified path.
*/
fn make_dir(p: path, mode: c_int) -> bool {
    ret mkdir(p, mode);

    #[cfg(target_os = "win32")]
    fn mkdir(p: path, _mode: c_int) -> bool unsafe {
        // FIXME: remove imports when export globs work properly.
        import libc::types::os::arch::extra::*;
        import libc::funcs::extra::kernel32::*;
        import win32::*;
        // FIXME: turn mode into something useful?
        as_utf16_p(p) {|buf|
            CreateDirectoryW(buf, unsafe::reinterpret_cast(0))
                != (0 as BOOL)
        }
    }

    #[cfg(target_os = "linux")]
    #[cfg(target_os = "macos")]
    #[cfg(target_os = "freebsd")]
    fn mkdir(p: path, mode: c_int) -> bool {
        as_c_charp(p) {|c|
            libc::mkdir(c, mode as mode_t) == (0 as c_int)
        }
    }
}

/*
Function: list_dir

Lists the contents of a directory.
*/
fn list_dir(p: path) -> [str] {

    #[cfg(target_os = "linux")]
    #[cfg(target_os = "macos")]
    #[cfg(target_os = "freebsd")]
    fn star() -> str { "" }

    #[cfg(target_os = "win32")]
    fn star() -> str { "*" }

    let mut p = p;
    let pl = str::len(p);
    if pl == 0u || (p[pl - 1u] as char != path::consts::path_sep
                    && p[pl - 1u] as char != path::consts::alt_path_sep) {
        p += path::path_sep();
    }
    let mut full_paths: [str] = [];
    for filename: str in rustrt::rust_list_files(p + star()) {
        if !str::eq(filename, ".") {
            if !str::eq(filename, "..") {
                full_paths += [p + filename];
            }
        }
    }
    ret full_paths;
}

/*
Function: remove_dir

Removes a directory at the specified path.
*/
fn remove_dir(p: path) -> bool {
   ret rmdir(p);

    #[cfg(target_os = "win32")]
    fn rmdir(p: path) -> bool {
        // FIXME: remove imports when export globs work properly.
        import libc::funcs::extra::kernel32::*;
        import libc::types::os::arch::extra::*;
        import win32::*;
        ret as_utf16_p(p) {|buf|
            RemoveDirectoryW(buf) != (0 as BOOL)
        };
    }

    #[cfg(target_os = "linux")]
    #[cfg(target_os = "macos")]
    #[cfg(target_os = "freebsd")]
    fn rmdir(p: path) -> bool {
        ret as_c_charp(p) {|buf|
            libc::rmdir(buf) == (0 as c_int)
        };
    }
}

fn change_dir(p: path) -> bool {
    ret chdir(p);

    #[cfg(target_os = "win32")]
    fn chdir(p: path) -> bool {
        // FIXME: remove imports when export globs work properly.
        import libc::funcs::extra::kernel32::*;
        import libc::types::os::arch::extra::*;
        import win32::*;
        ret as_utf16_p(p) {|buf|
            SetCurrentDirectoryW(buf) != (0 as BOOL)
        };
    }

    #[cfg(target_os = "linux")]
    #[cfg(target_os = "macos")]
    #[cfg(target_os = "freebsd")]
    fn chdir(p: path) -> bool {
        ret as_c_charp(p) {|buf|
            libc::chdir(buf) == (0 as c_int)
        };
    }
}

/*
Function: remove_file

Deletes an existing file.
*/
fn remove_file(p: path) -> bool {
    ret unlink(p);

    #[cfg(target_os = "win32")]
    fn unlink(p: path) -> bool {
        // FIXME: remove imports when export globs work properly.
        import libc::funcs::extra::kernel32::*;
        import libc::types::os::arch::extra::*;
        import win32::*;
        ret as_utf16_p(p) {|buf|
            DeleteFileW(buf) != (0 as BOOL)
        };
    }

    #[cfg(target_os = "linux")]
    #[cfg(target_os = "macos")]
    #[cfg(target_os = "freebsd")]
    fn unlink(p: path) -> bool {
        ret as_c_charp(p) {|buf|
            libc::unlink(buf) == (0 as c_int)
        };
    }
}



#[cfg(target_os = "macos")]
mod consts {
    fn sysname() -> str { "macos" }
    fn exe_suffix() -> str { "" }
    fn dll_suffix() -> str { ".dylib" }
}

#[cfg(target_os = "freebsd")]
mod consts {
    fn sysname() -> str { "freebsd" }
    fn exe_suffix() -> str { "" }
    fn dll_suffix() -> str { ".so" }
}

#[cfg(target_os = "linux")]
mod consts {
    fn sysname() -> str { "linux" }
    fn exe_suffix() -> str { "" }
    fn dll_suffix() -> str { ".so" }
}

#[cfg(target_os = "win32")]
mod consts {
    fn sysname() -> str { "win32" }
    fn exe_suffix() -> str { ".exe" }
    fn dll_suffix() -> str { ".dll" }
}




#[cfg(test)]
mod tests {

    #[test]
    fn test() {
        assert (!path::path_is_absolute("test-path"));

        log(debug, "Current working directory: " + getcwd());

        log(debug, make_absolute("test-path"));
        log(debug, make_absolute("/usr/bin"));
    }

    #[test]
    #[cfg(target_os = "linux")]
    #[cfg(target_os = "macos")]
    #[cfg(target_os = "freebsd")]
    fn homedir() {
        let oldhome = getenv("HOME");

        setenv("HOME", "/home/MountainView");
        assert os::homedir() == some("/home/MountainView");

        setenv("HOME", "");
        assert os::homedir() == none;

        option::may(oldhome, {|s| setenv("HOME", s)});
    }

    #[test]
    #[cfg(target_os = "win32")]
    fn homedir() {

        let oldhome = getenv("HOME");
        let olduserprofile = getenv("USERPROFILE");

        setenv("HOME", "");
        setenv("USERPROFILE", "");

        assert os::homedir() == none;

        setenv("HOME", "/home/MountainView");
        assert os::homedir() == some("/home/MountainView");

        setenv("HOME", "");

        setenv("USERPROFILE", "/home/MountainView");
        assert os::homedir() == some("/home/MountainView");

        setenv("USERPROFILE", "/home/MountainView");
        assert os::homedir() == some("/home/MountainView");

        setenv("HOME", "/home/MountainView");
        setenv("USERPROFILE", "/home/PaloAlto");
        assert os::homedir() == some("/home/MountainView");

        option::may(oldhome, {|s| setenv("HOME", s)});
        option::may(olduserprofile, {|s| setenv("USERPROFILE", s)});
    }

    // Issue #712
    #[test]
    fn test_list_dir_no_invalid_memory_access() { os::list_dir("."); }

    #[test]
    fn list_dir() {
        let dirs = os::list_dir(".");
        // Just assuming that we've got some contents in the current directory
        assert (vec::len(dirs) > 0u);

        for dir in dirs { log(debug, dir); }
    }

    #[test]
    fn path_is_dir() {
        assert (os::path_is_dir("."));
        assert (!os::path_is_dir("test/stdtest/fs.rs"));
    }

    #[test]
    fn path_exists() {
        assert (os::path_exists("."));
        assert (!os::path_exists("test/nonexistent-bogus-path"));
    }

}