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// This file contains thin wrappers around OS-specific APIs, with these
// specific goals in mind:
// * Convert "errno"-style error codes into Zig errors.
// * When null-terminated byte buffers are required, provide APIs which accept
// slices as well as APIs which accept null-terminated byte buffers. Same goes
// for UTF-16LE encoding.
// * Where operating systems share APIs, e.g. POSIX, these thin wrappers provide
// cross platform abstracting.
// * When there exists a corresponding libc function and linking libc, the libc
// implementation is used. Exceptions are made for known buggy areas of libc.
// On Linux libc can be side-stepped by using `std.os.linux` directly.
// * For Windows, this file represents the API that libc would provide for
// Windows. For thin wrappers around Windows-specific APIs, see `std.os.windows`.
// Note: The Zig standard library does not support POSIX thread cancellation, and
// in general EINTR is handled by trying again.
const root = @import("root");
const std = @import("std.zig");
const builtin = @import("builtin");
const assert = std.debug.assert;
const math = std.math;
const mem = std.mem;
const elf = std.elf;
const dl = @import("dynamic_library.zig");
const MAX_PATH_BYTES = std.fs.MAX_PATH_BYTES;
pub const darwin = @import("os/darwin.zig");
pub const dragonfly = @import("os/dragonfly.zig");
pub const freebsd = @import("os/freebsd.zig");
pub const netbsd = @import("os/netbsd.zig");
pub const linux = @import("os/linux.zig");
pub const uefi = @import("os/uefi.zig");
pub const wasi = @import("os/wasi.zig");
pub const windows = @import("os/windows.zig");
comptime {
assert(@import("std") == std); // std lib tests require --override-lib-dir
}
test "" {
_ = darwin;
_ = freebsd;
_ = linux;
_ = netbsd;
_ = uefi;
_ = wasi;
_ = windows;
_ = @import("os/test.zig");
}
/// Applications can override the `system` API layer in their root source file.
/// Otherwise, when linking libc, this is the C API.
/// When not linking libc, it is the OS-specific system interface.
pub const system = if (@hasDecl(root, "os") and root.os != @This())
root.os.system
else if (builtin.link_libc)
std.c
else switch (builtin.os.tag) {
.macosx, .ios, .watchos, .tvos => darwin,
.freebsd => freebsd,
.linux => linux,
.netbsd => netbsd,
.dragonfly => dragonfly,
.wasi => wasi,
.windows => windows,
else => struct {},
};
pub usingnamespace @import("os/bits.zig");
/// See also `getenv`. Populated by startup code before main().
/// TODO this is a footgun because the value will be undefined when using `zig build-lib`.
/// https://github.com/ziglang/zig/issues/4524
pub var environ: [][*:0]u8 = undefined;
/// Populated by startup code before main().
/// Not available on Windows. See `std.process.args`
/// for obtaining the process arguments.
pub var argv: [][*:0]u8 = undefined;
/// To obtain errno, call this function with the return value of the
/// system function call. For some systems this will obtain the value directly
/// from the return code; for others it will use a thread-local errno variable.
/// Therefore, this function only returns a well-defined value when it is called
/// directly after the system function call which one wants to learn the errno
/// value of.
pub const errno = system.getErrno;
/// Closes the file descriptor.
/// This function is not capable of returning any indication of failure. An
/// application which wants to ensure writes have succeeded before closing
/// must call `fsync` before `close`.
/// Note: The Zig standard library does not support POSIX thread cancellation.
pub fn close(fd: fd_t) void {
if (builtin.os.tag == .windows) {
return windows.CloseHandle(fd);
}
if (builtin.os.tag == .wasi) {
_ = wasi.fd_close(fd);
}
if (comptime std.Target.current.isDarwin()) {
// This avoids the EINTR problem.
switch (darwin.getErrno(darwin.@"close$NOCANCEL"(fd))) {
EBADF => unreachable, // Always a race condition.
else => return,
}
}
switch (errno(system.close(fd))) {
EBADF => unreachable, // Always a race condition.
EINTR => return, // This is still a success. See https://github.com/ziglang/zig/issues/2425
else => return,
}
}
pub const GetRandomError = OpenError;
/// Obtain a series of random bytes. These bytes can be used to seed user-space
/// random number generators or for cryptographic purposes.
/// When linking against libc, this calls the
/// appropriate OS-specific library call. Otherwise it uses the zig standard
/// library implementation.
pub fn getrandom(buffer: []u8) GetRandomError!void {
if (builtin.os.tag == .windows) {
return windows.RtlGenRandom(buffer);
}
if (builtin.os.tag == .linux or builtin.os.tag == .freebsd) {
var buf = buffer;
const use_c = builtin.os.tag != .linux or
std.c.versionCheck(builtin.Version{ .major = 2, .minor = 25, .patch = 0 }).ok;
while (buf.len != 0) {
var err: u16 = undefined;
const num_read = if (use_c) blk: {
const rc = std.c.getrandom(buf.ptr, buf.len, 0);
err = std.c.getErrno(rc);
break :blk @bitCast(usize, rc);
} else blk: {
const rc = linux.getrandom(buf.ptr, buf.len, 0);
err = linux.getErrno(rc);
break :blk rc;
};
switch (err) {
0 => buf = buf[num_read..],
EINVAL => unreachable,
EFAULT => unreachable,
EINTR => continue,
ENOSYS => return getRandomBytesDevURandom(buf),
else => return unexpectedErrno(err),
}
}
return;
}
if (builtin.os.tag == .wasi) {
switch (wasi.random_get(buffer.ptr, buffer.len)) {
0 => return,
else => |err| return unexpectedErrno(err),
}
}
return getRandomBytesDevURandom(buffer);
}
fn getRandomBytesDevURandom(buf: []u8) !void {
const fd = try openZ("/dev/urandom", O_RDONLY | O_CLOEXEC, 0);
defer close(fd);
const st = try fstat(fd);
if (!S_ISCHR(st.mode)) {
return error.NoDevice;
}
const file = std.fs.File{
.handle = fd,
.io_mode = .blocking,
.async_block_allowed = std.fs.File.async_block_allowed_yes,
};
const stream = file.inStream();
stream.readNoEof(buf) catch return error.Unexpected;
}
/// Causes abnormal process termination.
/// If linking against libc, this calls the abort() libc function. Otherwise
/// it raises SIGABRT followed by SIGKILL and finally lo
pub fn abort() noreturn {
@setCold(true);
// MSVCRT abort() sometimes opens a popup window which is undesirable, so
// even when linking libc on Windows we use our own abort implementation.
// See https://github.com/ziglang/zig/issues/2071 for more details.
if (builtin.os.tag == .windows) {
if (builtin.mode == .Debug) {
@breakpoint();
}
windows.kernel32.ExitProcess(3);
}
if (!builtin.link_libc and builtin.os.tag == .linux) {
raise(SIGABRT) catch {};
// TODO the rest of the implementation of abort() from musl libc here
raise(SIGKILL) catch {};
exit(127);
}
if (builtin.os.tag == .uefi) {
exit(0); // TODO choose appropriate exit code
}
if (builtin.os.tag == .wasi) {
@breakpoint();
exit(1);
}
system.abort();
}
pub const RaiseError = UnexpectedError;
pub fn raise(sig: u8) RaiseError!void {
if (builtin.link_libc) {
switch (errno(system.raise(sig))) {
0 => return,
else => |err| return unexpectedErrno(err),
}
}
if (builtin.os.tag == .linux) {
var set: linux.sigset_t = undefined;
// block application signals
_ = linux.sigprocmask(SIG_BLOCK, &linux.app_mask, &set);
const tid = linux.gettid();
const rc = linux.tkill(tid, sig);
// restore signal mask
_ = linux.sigprocmask(SIG_SETMASK, &set, null);
switch (errno(rc)) {
0 => return,
else => |err| return unexpectedErrno(err),
}
}
@compileError("std.os.raise unimplemented for this target");
}
pub const KillError = error{PermissionDenied} || UnexpectedError;
pub fn kill(pid: pid_t, sig: u8) KillError!void {
switch (errno(system.kill(pid, sig))) {
0 => return,
EINVAL => unreachable, // invalid signal
EPERM => return error.PermissionDenied,
ESRCH => unreachable, // always a race condition
else => |err| return unexpectedErrno(err),
}
}
/// Exits the program cleanly with the specified status code.
pub fn exit(status: u8) noreturn {
if (builtin.link_libc) {
system.exit(status);
}
if (builtin.os.tag == .windows) {
windows.kernel32.ExitProcess(status);
}
if (builtin.os.tag == .wasi) {
wasi.proc_exit(status);
}
if (builtin.os.tag == .linux and !builtin.single_threaded) {
linux.exit_group(status);
}
if (builtin.os.tag == .uefi) {
// exit() is only avaliable if exitBootServices() has not been called yet.
// This call to exit should not fail, so we don't care about its return value.
if (uefi.system_table.boot_services) |bs| {
_ = bs.exit(uefi.handle, @intToEnum(uefi.Status, status), 0, null);
}
// If we can't exit, reboot the system instead.
uefi.system_table.runtime_services.resetSystem(uefi.tables.ResetType.ResetCold, @intToEnum(uefi.Status, status), 0, null);
}
system.exit(status);
}
pub const ReadError = error{
InputOutput,
SystemResources,
IsDir,
OperationAborted,
BrokenPipe,
ConnectionResetByPeer,
/// This error occurs when no global event loop is configured,
/// and reading from the file descriptor would block.
WouldBlock,
} || UnexpectedError;
/// Returns the number of bytes that were read, which can be less than
/// buf.len. If 0 bytes were read, that means EOF.
/// If the application has a global event loop enabled, EAGAIN is handled
/// via the event loop. Otherwise EAGAIN results in error.WouldBlock.
///
/// Linux has a limit on how many bytes may be transferred in one `read` call, which is `0x7ffff000`
/// on both 64-bit and 32-bit systems. This is due to using a signed C int as the return value, as
/// well as stuffing the errno codes into the last `4096` values. This is noted on the `read` man page.
/// For POSIX the limit is `math.maxInt(isize)`.
pub fn read(fd: fd_t, buf: []u8) ReadError!usize {
if (builtin.os.tag == .windows) {
return windows.ReadFile(fd, buf, null);
}
if (builtin.os.tag == .wasi and !builtin.link_libc) {
const iovs = [1]iovec{iovec{
.iov_base = buf.ptr,
.iov_len = buf.len,
}};
var nread: usize = undefined;
switch (wasi.fd_read(fd, &iovs, iovs.len, &nread)) {
0 => return nread,
else => |err| return unexpectedErrno(err),
}
}
// Prevents EINVAL.
const max_count = switch (std.Target.current.os.tag) {
.linux => 0x7ffff000,
else => math.maxInt(isize),
};
const adjusted_len = math.min(max_count, buf.len);
while (true) {
const rc = system.read(fd, buf.ptr, adjusted_len);
switch (errno(rc)) {
0 => return @intCast(usize, rc),
EINTR => continue,
EINVAL => unreachable,
EFAULT => unreachable,
EAGAIN => if (std.event.Loop.instance) |loop| {
loop.waitUntilFdReadable(fd);
continue;
} else {
return error.WouldBlock;
},
EBADF => unreachable, // Always a race condition.
EIO => return error.InputOutput,
EISDIR => return error.IsDir,
ENOBUFS => return error.SystemResources,
ENOMEM => return error.SystemResources,
ECONNRESET => return error.ConnectionResetByPeer,
else => |err| return unexpectedErrno(err),
}
}
return index;
}
/// Number of bytes read is returned. Upon reading end-of-file, zero is returned.
///
/// For POSIX systems, if the application has a global event loop enabled, EAGAIN is handled
/// via the event loop. Otherwise EAGAIN results in `error.WouldBlock`.
/// On Windows, if the application has a global event loop enabled, I/O Completion Ports are
/// used to perform the I/O. `error.WouldBlock` is not possible on Windows.
///
/// This operation is non-atomic on the following systems:
/// * Windows
/// On these systems, the read races with concurrent writes to the same file descriptor.
pub fn readv(fd: fd_t, iov: []const iovec) ReadError!usize {
if (std.Target.current.os.tag == .windows) {
// TODO does Windows have a way to read an io vector?
if (iov.len == 0) return @as(usize, 0);
const first = iov[0];
return read(fd, first.iov_base[0..first.iov_len]);
}
while (true) {
// TODO handle the case when iov_len is too large and get rid of this @intCast
const rc = system.readv(fd, iov.ptr, iov_count);
switch (errno(rc)) {
0 => return @intCast(usize, rc),
EINTR => continue,
EINVAL => unreachable,
EFAULT => unreachable,
EAGAIN => if (std.event.Loop.instance) |loop| {
loop.waitUntilFdReadable(fd);
continue;
} else {
return error.WouldBlock;
},
EBADF => unreachable, // always a race condition
EIO => return error.InputOutput,
EISDIR => return error.IsDir,
ENOBUFS => return error.SystemResources,
ENOMEM => return error.SystemResources,
else => |err| return unexpectedErrno(err),
}
}
}
pub const PReadError = ReadError || error{Unseekable};
/// Number of bytes read is returned. Upon reading end-of-file, zero is returned.
///
/// Retries when interrupted by a signal.
///
/// For POSIX systems, if the application has a global event loop enabled, EAGAIN is handled
/// via the event loop. Otherwise EAGAIN results in `error.WouldBlock`.
/// On Windows, if the application has a global event loop enabled, I/O Completion Ports are
/// used to perform the I/O. `error.WouldBlock` is not possible on Windows.
pub fn pread(fd: fd_t, buf: []u8, offset: u64) PReadError!usize {
if (builtin.os.tag == .windows) {
return windows.ReadFile(fd, buf, offset);
}
while (true) {
const rc = system.pread(fd, buf.ptr, buf.len, offset);
switch (errno(rc)) {
0 => return @intCast(usize, rc),
EINTR => continue,
EINVAL => unreachable,
EFAULT => unreachable,
EAGAIN => if (std.event.Loop.instance) |loop| {
loop.waitUntilFdReadable(fd);
continue;
} else {
return error.WouldBlock;
},
EBADF => unreachable, // Always a race condition.
EIO => return error.InputOutput,
EISDIR => return error.IsDir,
ENOBUFS => return error.SystemResources,
ENOMEM => return error.SystemResources,
ECONNRESET => return error.ConnectionResetByPeer,
ENXIO => return error.Unseekable,
ESPIPE => return error.Unseekable,
EOVERFLOW => return error.Unseekable,
else => |err| return unexpectedErrno(err),
}
}
return index;
}
pub const TruncateError = error{
FileTooBig,
InputOutput,
CannotTruncate,
FileBusy,
} || UnexpectedError;
pub fn ftruncate(fd: fd_t, length: u64) TruncateError!void {
if (std.Target.current.os.tag == .windows) {
var io_status_block: windows.IO_STATUS_BLOCK = undefined;
var eof_info = windows.FILE_END_OF_FILE_INFORMATION{
.EndOfFile = @bitCast(windows.LARGE_INTEGER, length),
};
const rc = windows.ntdll.NtSetInformationFile(
fd,
&io_status_block,
&eof_info,
@sizeOf(windows.FILE_END_OF_FILE_INFORMATION),
.FileEndOfFileInformation,
);
switch (rc) {
.SUCCESS => return,
.INVALID_HANDLE => unreachable, // Handle not open for writing
.ACCESS_DENIED => return error.CannotTruncate,
else => return windows.unexpectedStatus(rc),
}
}
while (true) {
const rc = if (builtin.link_libc)
if (std.Target.current.os.tag == .linux)
system.ftruncate64(fd, @bitCast(off_t, length))
else
system.ftruncate(fd, @bitCast(off_t, length))
else
system.ftruncate(fd, length);
switch (errno(rc)) {
0 => return,
EINTR => continue,
EFBIG => return error.FileTooBig,
EIO => return error.InputOutput,
EPERM => return error.CannotTruncate,
ETXTBSY => return error.FileBusy,
EBADF => unreachable, // Handle not open for writing
EINVAL => unreachable, // Handle not open for writing
else => |err| return unexpectedErrno(err),
}
}
}
/// Number of bytes read is returned. Upon reading end-of-file, zero is returned.
///
/// Retries when interrupted by a signal.
///
/// For POSIX systems, if the application has a global event loop enabled, EAGAIN is handled
/// via the event loop. Otherwise EAGAIN results in `error.WouldBlock`.
/// On Windows, if the application has a global event loop enabled, I/O Completion Ports are
/// used to perform the I/O. `error.WouldBlock` is not possible on Windows.
///
/// This operation is non-atomic on the following systems:
/// * Darwin
/// * Windows
/// On these systems, the read races with concurrent writes to the same file descriptor.
pub fn preadv(fd: fd_t, iov: []const iovec, offset: u64) PReadError!usize {
const have_pread_but_not_preadv = switch (std.Target.current.os.tag) {
.windows, .macosx, .ios, .watchos, .tvos => true,
else => false,
};
if (have_pread_but_not_preadv) {
// We could loop here; but proper usage of `preadv` must handle partial reads anyway.
// So we simply read into the first vector only.
if (iov.len == 0) return @as(usize, 0);
const first = iov[0];
return pread(fd, first.iov_base[0..first.iov_len], offset);
}
const iov_count = math.cast(u31, iov.len) catch math.maxInt(u31);
while (true) {
const rc = system.preadv(fd, iov.ptr, iov_count, offset);
switch (errno(rc)) {
0 => return @bitCast(usize, rc),
EINTR => continue,
EINVAL => unreachable,
EFAULT => unreachable,
EAGAIN => if (std.event.Loop.instance) |loop| {
loop.waitUntilFdReadable(fd);
continue;
} else {
return error.WouldBlock;
},
EBADF => unreachable, // always a race condition
EIO => return error.InputOutput,
EISDIR => return error.IsDir,
ENOBUFS => return error.SystemResources,
ENOMEM => return error.SystemResources,
ENXIO => return error.Unseekable,
ESPIPE => return error.Unseekable,
EOVERFLOW => return error.Unseekable,
else => |err| return unexpectedErrno(err),
}
}
}
pub const WriteError = error{
DiskQuota,
FileTooBig,
InputOutput,
NoSpaceLeft,
AccessDenied,
BrokenPipe,
SystemResources,
OperationAborted,
/// This error occurs when no global event loop is configured,
/// and reading from the file descriptor would block.
WouldBlock,
} || UnexpectedError;
/// Write to a file descriptor.
/// Retries when interrupted by a signal.
/// Returns the number of bytes written. If nonzero bytes were supplied, this will be nonzero.
///
/// Note that a successful write() may transfer fewer than count bytes. Such partial writes can
/// occur for various reasons; for example, because there was insufficient space on the disk
/// device to write all of the requested bytes, or because a blocked write() to a socket, pipe, or
/// similar was interrupted by a signal handler after it had transferred some, but before it had
/// transferred all of the requested bytes. In the event of a partial write, the caller can make
/// another write() call to transfer the remaining bytes. The subsequent call will either
/// transfer further bytes or may result in an error (e.g., if the disk is now full).
///
/// For POSIX systems, if the application has a global event loop enabled, EAGAIN is handled
/// via the event loop. Otherwise EAGAIN results in `error.WouldBlock`.
/// On Windows, if the application has a global event loop enabled, I/O Completion Ports are
/// used to perform the I/O. `error.WouldBlock` is not possible on Windows.
///
/// Linux has a limit on how many bytes may be transferred in one `write` call, which is `0x7ffff000`
/// on both 64-bit and 32-bit systems. This is due to using a signed C int as the return value, as
/// well as stuffing the errno codes into the last `4096` values. This is noted on the `write` man page.
/// The corresponding POSIX limit is `math.maxInt(isize)`.
pub fn write(fd: fd_t, bytes: []const u8) WriteError!usize {
if (builtin.os.tag == .windows) {
return windows.WriteFile(fd, bytes, null);
}
if (builtin.os.tag == .wasi and !builtin.link_libc) {
const ciovs = [1]iovec_const{iovec_const{
.iov_base = bytes.ptr,
.iov_len = bytes.len,
}};
var nwritten: usize = undefined;
switch (wasi.fd_write(fd, &ciovs, ciovs.len, &nwritten)) {
0 => return nwritten,
else => |err| return unexpectedErrno(err),
}
}
const max_count = switch (std.Target.current.os.tag) {
.linux => 0x7ffff000,
else => math.maxInt(isize),
};
const adjusted_len = math.min(max_count, bytes.len);
while (true) {
const rc = system.write(fd, bytes.ptr, adjusted_len);
switch (errno(rc)) {
0 => return @intCast(usize, rc),
EINTR => continue,
EINVAL => unreachable,
EFAULT => unreachable,
EAGAIN => if (std.event.Loop.instance) |loop| {
loop.waitUntilFdWritable(fd);
continue;
} else {
return error.WouldBlock;
},
EBADF => unreachable, // Always a race condition.
EDESTADDRREQ => unreachable, // `connect` was never called.
EDQUOT => return error.DiskQuota,
EFBIG => return error.FileTooBig,
EIO => return error.InputOutput,
ENOSPC => return error.NoSpaceLeft,
EPERM => return error.AccessDenied,
EPIPE => return error.BrokenPipe,
else => |err| return unexpectedErrno(err),
}
}
}
/// Write multiple buffers to a file descriptor.
/// Retries when interrupted by a signal.
/// Returns the number of bytes written. If nonzero bytes were supplied, this will be nonzero.
///
/// Note that a successful write() may transfer fewer bytes than supplied. Such partial writes can
/// occur for various reasons; for example, because there was insufficient space on the disk
/// device to write all of the requested bytes, or because a blocked write() to a socket, pipe, or
/// similar was interrupted by a signal handler after it had transferred some, but before it had
/// transferred all of the requested bytes. In the event of a partial write, the caller can make
/// another write() call to transfer the remaining bytes. The subsequent call will either
/// transfer further bytes or may result in an error (e.g., if the disk is now full).
///
/// For POSIX systems, if the application has a global event loop enabled, EAGAIN is handled
/// via the event loop. Otherwise EAGAIN results in `error.WouldBlock`.
/// On Windows, if the application has a global event loop enabled, I/O Completion Ports are
/// used to perform the I/O. `error.WouldBlock` is not possible on Windows.
///
/// If `iov.len` is larger than will fit in a `u31`, a partial write will occur.
pub fn writev(fd: fd_t, iov: []const iovec_const) WriteError!usize {
if (std.Target.current.os.tag == .windows) {
// TODO does Windows have a way to write an io vector?
if (iov.len == 0) return @as(usize, 0);
const first = iov[0];
return write(fd, first.iov_base[0..first.iov_len]);
}
const iov_count = math.cast(u31, iov.len) catch math.maxInt(u31);
while (true) {
const rc = system.writev(fd, iov.ptr, iov_count);
switch (errno(rc)) {
0 => return @intCast(usize, rc),
EINTR => continue,
EINVAL => unreachable,
EFAULT => unreachable,
EAGAIN => if (std.event.Loop.instance) |loop| {
loop.waitUntilFdWritable(fd);
continue;
} else {
return error.WouldBlock;
},
EBADF => unreachable, // Always a race condition.
EDESTADDRREQ => unreachable, // `connect` was never called.
EDQUOT => return error.DiskQuota,
EFBIG => return error.FileTooBig,
EIO => return error.InputOutput,
ENOSPC => return error.NoSpaceLeft,
EPERM => return error.AccessDenied,
EPIPE => return error.BrokenPipe,
else => |err| return unexpectedErrno(err),
}
}
}
pub const PWriteError = WriteError || error{Unseekable};
/// Write to a file descriptor, with a position offset.
/// Retries when interrupted by a signal.
/// Returns the number of bytes written. If nonzero bytes were supplied, this will be nonzero.
///
/// Note that a successful write() may transfer fewer bytes than supplied. Such partial writes can
/// occur for various reasons; for example, because there was insufficient space on the disk
/// device to write all of the requested bytes, or because a blocked write() to a socket, pipe, or
/// similar was interrupted by a signal handler after it had transferred some, but before it had
/// transferred all of the requested bytes. In the event of a partial write, the caller can make
/// another write() call to transfer the remaining bytes. The subsequent call will either
/// transfer further bytes or may result in an error (e.g., if the disk is now full).
///
/// For POSIX systems, if the application has a global event loop enabled, EAGAIN is handled
/// via the event loop. Otherwise EAGAIN results in `error.WouldBlock`.
/// On Windows, if the application has a global event loop enabled, I/O Completion Ports are
/// used to perform the I/O. `error.WouldBlock` is not possible on Windows.
///
/// Linux has a limit on how many bytes may be transferred in one `pwrite` call, which is `0x7ffff000`
/// on both 64-bit and 32-bit systems. This is due to using a signed C int as the return value, as
/// well as stuffing the errno codes into the last `4096` values. This is noted on the `write` man page.
/// The corresponding POSIX limit is `math.maxInt(isize)`.
pub fn pwrite(fd: fd_t, bytes: []const u8, offset: u64) PWriteError!usize {
if (std.Target.current.os.tag == .windows) {
return windows.WriteFile(fd, bytes, offset);
}
// Prevent EINVAL.
const max_count = switch (std.Target.current.os.tag) {
.linux => 0x7ffff000,
else => math.maxInt(isize),
};
const adjusted_len = math.min(max_count, bytes.len);
while (true) {
const rc = system.pwrite(fd, bytes.ptr, adjusted_len, offset);
switch (errno(rc)) {
0 => return @intCast(usize, rc),
EINTR => continue,
EINVAL => unreachable,
EFAULT => unreachable,
EAGAIN => if (std.event.Loop.instance) |loop| {
loop.waitUntilFdWritable(fd);
continue;
} else {
return error.WouldBlock;
},
EBADF => unreachable, // Always a race condition.
EDESTADDRREQ => unreachable, // `connect` was never called.
EDQUOT => return error.DiskQuota,
EFBIG => return error.FileTooBig,
EIO => return error.InputOutput,
ENOSPC => return error.NoSpaceLeft,
EPERM => return error.AccessDenied,
EPIPE => return error.BrokenPipe,
ENXIO => return error.Unseekable,
ESPIPE => return error.Unseekable,
EOVERFLOW => return error.Unseekable,
else => |err| return unexpectedErrno(err),
}
}
}
/// Write multiple buffers to a file descriptor, with a position offset.
/// Retries when interrupted by a signal.
/// Returns the number of bytes written. If nonzero bytes were supplied, this will be nonzero.
///
/// Note that a successful write() may transfer fewer than count bytes. Such partial writes can
/// occur for various reasons; for example, because there was insufficient space on the disk
/// device to write all of the requested bytes, or because a blocked write() to a socket, pipe, or
/// similar was interrupted by a signal handler after it had transferred some, but before it had
/// transferred all of the requested bytes. In the event of a partial write, the caller can make
/// another write() call to transfer the remaining bytes. The subsequent call will either
/// transfer further bytes or may result in an error (e.g., if the disk is now full).
///
/// If the application has a global event loop enabled, EAGAIN is handled
/// via the event loop. Otherwise EAGAIN results in `error.WouldBlock`.
///
/// The following systems do not have this syscall, and will return partial writes if more than one
/// vector is provided:
/// * Darwin
/// * Windows
///
/// If `iov.len` is larger than will fit in a `u31`, a partial write will occur.
pub fn pwritev(fd: fd_t, iov: []const iovec_const, offset: u64) PWriteError!usize {
const have_pwrite_but_not_pwritev = switch (std.Target.current.os.tag) {
.windows, .macosx, .ios, .watchos, .tvos => true,
else => false,
};
if (have_pwrite_but_not_pwritev) {
// We could loop here; but proper usage of `pwritev` must handle partial writes anyway.
// So we simply write the first vector only.
if (iov.len == 0) return @as(usize, 0);
const first = iov[0];
return pwrite(fd, first.iov_base[0..first.iov_len], offset);
}
const iov_count = math.cast(u31, iov.len) catch math.maxInt(u31);
while (true) {
const rc = system.pwritev(fd, iov.ptr, iov_count, offset);
switch (errno(rc)) {
0 => return @intCast(usize, rc),
EINTR => continue,
EINVAL => unreachable,
EFAULT => unreachable,
EAGAIN => if (std.event.Loop.instance) |loop| {
loop.waitUntilFdWritable(fd);
continue;
} else {
return error.WouldBlock;
},
EBADF => unreachable, // Always a race condition.
EDESTADDRREQ => unreachable, // `connect` was never called.
EDQUOT => return error.DiskQuota,
EFBIG => return error.FileTooBig,
EIO => return error.InputOutput,
ENOSPC => return error.NoSpaceLeft,
EPERM => return error.AccessDenied,
EPIPE => return error.BrokenPipe,
ENXIO => return error.Unseekable,
ESPIPE => return error.Unseekable,
EOVERFLOW => return error.Unseekable,
else => |err| return unexpectedErrno(err),
}
}
}
pub const OpenError = error{
AccessDenied,
SymLinkLoop,
ProcessFdQuotaExceeded,
SystemFdQuotaExceeded,
NoDevice,
FileNotFound,
/// The path exceeded `MAX_PATH_BYTES` bytes.
NameTooLong,
/// Insufficient kernel memory was available, or
/// the named file is a FIFO and per-user hard limit on
/// memory allocation for pipes has been reached.
SystemResources,
/// The file is too large to be opened. This error is unreachable
/// for 64-bit targets, as well as when opening directories.
FileTooBig,
/// The path refers to directory but the `O_DIRECTORY` flag was not provided.
IsDir,
/// A new path cannot be created because the device has no room for the new file.
/// This error is only reachable when the `O_CREAT` flag is provided.
NoSpaceLeft,
/// A component used as a directory in the path was not, in fact, a directory, or
/// `O_DIRECTORY` was specified and the path was not a directory.
NotDir,
/// The path already exists and the `O_CREAT` and `O_EXCL` flags were provided.
PathAlreadyExists,
DeviceBusy,
} || UnexpectedError;
/// Open and possibly create a file. Keeps trying if it gets interrupted.
/// See also `openC`.
/// TODO support windows
pub fn open(file_path: []const u8, flags: u32, perm: usize) OpenError!fd_t {
const file_path_c = try toPosixPath(file_path);
return openZ(&file_path_c, flags, perm);
}
pub const openC = @compileError("deprecated: renamed to openZ");
/// Open and possibly create a file. Keeps trying if it gets interrupted.
/// See also `open`.
/// TODO support windows
pub fn openZ(file_path: [*:0]const u8, flags: u32, perm: usize) OpenError!fd_t {
while (true) {
const rc = system.open(file_path, flags, perm);
switch (errno(rc)) {
0 => return @intCast(fd_t, rc),
EINTR => continue,
EFAULT => unreachable,
EINVAL => unreachable,
EACCES => return error.AccessDenied,
EFBIG => return error.FileTooBig,
EOVERFLOW => return error.FileTooBig,
EISDIR => return error.IsDir,
ELOOP => return error.SymLinkLoop,
EMFILE => return error.ProcessFdQuotaExceeded,
ENAMETOOLONG => return error.NameTooLong,
ENFILE => return error.SystemFdQuotaExceeded,
ENODEV => return error.NoDevice,
ENOENT => return error.FileNotFound,
ENOMEM => return error.SystemResources,
ENOSPC => return error.NoSpaceLeft,
ENOTDIR => return error.NotDir,
EPERM => return error.AccessDenied,
EEXIST => return error.PathAlreadyExists,
EBUSY => return error.DeviceBusy,
else => |err| return unexpectedErrno(err),
}
}
}
/// Open and possibly create a file. Keeps trying if it gets interrupted.
/// `file_path` is relative to the open directory handle `dir_fd`.
/// See also `openatC`.
/// TODO support windows
pub fn openat(dir_fd: fd_t, file_path: []const u8, flags: u32, mode: mode_t) OpenError!fd_t {
const file_path_c = try toPosixPath(file_path);
return openatZ(dir_fd, &file_path_c, flags, mode);
}
pub const openatC = @compileError("deprecated: renamed to openatZ");
/// Open and possibly create a file. Keeps trying if it gets interrupted.
/// `file_path` is relative to the open directory handle `dir_fd`.
/// See also `openat`.
/// TODO support windows
pub fn openatZ(dir_fd: fd_t, file_path: [*:0]const u8, flags: u32, mode: mode_t) OpenError!fd_t {
while (true) {
const rc = system.openat(dir_fd, file_path, flags, mode);
switch (errno(rc)) {
0 => return @intCast(fd_t, rc),
EINTR => continue,
EFAULT => unreachable,
EINVAL => unreachable,
EACCES => return error.AccessDenied,
EFBIG => return error.FileTooBig,
EOVERFLOW => return error.FileTooBig,
EISDIR => return error.IsDir,
ELOOP => return error.SymLinkLoop,
EMFILE => return error.ProcessFdQuotaExceeded,
ENAMETOOLONG => return error.NameTooLong,
ENFILE => return error.SystemFdQuotaExceeded,
ENODEV => return error.NoDevice,
ENOENT => return error.FileNotFound,
ENOMEM => return error.SystemResources,
ENOSPC => return error.NoSpaceLeft,
ENOTDIR => return error.NotDir,
EPERM => return error.AccessDenied,
EEXIST => return error.PathAlreadyExists,
EBUSY => return error.DeviceBusy,
else => |err| return unexpectedErrno(err),
}
}
}
pub fn dup2(old_fd: fd_t, new_fd: fd_t) !void {
while (true) {
switch (errno(system.dup2(old_fd, new_fd))) {
0 => return,
EBUSY, EINTR => continue,
EMFILE => return error.ProcessFdQuotaExceeded,
EINVAL => unreachable, // invalid parameters passed to dup2
EBADF => unreachable, // always a race condition
else => |err| return unexpectedErrno(err),
}
}
}
pub const ExecveError = error{
SystemResources,
AccessDenied,
InvalidExe,
FileSystem,
IsDir,
FileNotFound,
NotDir,
FileBusy,
ProcessFdQuotaExceeded,
SystemFdQuotaExceeded,
NameTooLong,
} || UnexpectedError;
pub const execveC = @compileError("deprecated: use execveZ");
/// Like `execve` except the parameters are null-terminated,
/// matching the syscall API on all targets. This removes the need for an allocator.
/// This function ignores PATH environment variable. See `execvpeZ` for that.
pub fn execveZ(
path: [*:0]const u8,
child_argv: [*:null]const ?[*:0]const u8,
envp: [*:null]const ?[*:0]const u8,
) ExecveError {
switch (errno(system.execve(path, child_argv, envp))) {
0 => unreachable,
EFAULT => unreachable,
E2BIG => return error.SystemResources,
EMFILE => return error.ProcessFdQuotaExceeded,
ENAMETOOLONG => return error.NameTooLong,
ENFILE => return error.SystemFdQuotaExceeded,
ENOMEM => return error.SystemResources,
EACCES => return error.AccessDenied,
EPERM => return error.AccessDenied,
EINVAL => return error.InvalidExe,
ENOEXEC => return error.InvalidExe,
EIO => return error.FileSystem,
ELOOP => return error.FileSystem,
EISDIR => return error.IsDir,
ENOENT => return error.FileNotFound,
ENOTDIR => return error.NotDir,
ETXTBSY => return error.FileBusy,
else => |err| return unexpectedErrno(err),
}
}
pub const execvpeC = @compileError("deprecated in favor of execvpeZ");
pub const Arg0Expand = enum {
expand,
no_expand,
};
/// Like `execvpeZ` except if `arg0_expand` is `.expand`, then `argv` is mutable,
/// and `argv[0]` is expanded to be the same absolute path that is passed to the execve syscall.
/// If this function returns with an error, `argv[0]` will be restored to the value it was when it was passed in.
pub fn execvpeZ_expandArg0(
comptime arg0_expand: Arg0Expand,
file: [*:0]const u8,
child_argv: switch (arg0_expand) {
.expand => [*:null]?[*:0]const u8,
.no_expand => [*:null]const ?[*:0]const u8,
},
envp: [*:null]const ?[*:0]const u8,
) ExecveError {
const file_slice = mem.spanZ(file);
if (mem.indexOfScalar(u8, file_slice, '/') != null) return execveZ(file, child_argv, envp);
const PATH = getenvZ("PATH") orelse "/usr/local/bin:/bin/:/usr/bin";
var path_buf: [MAX_PATH_BYTES]u8 = undefined;
var it = mem.tokenize(PATH, ":");
var seen_eacces = false;
var err: ExecveError = undefined;
// In case of expanding arg0 we must put it back if we return with an error.
const prev_arg0 = child_argv[0];
defer switch (arg0_expand) {
.expand => child_argv[0] = prev_arg0,
.no_expand => {},
};
while (it.next()) |search_path| {
if (path_buf.len < search_path.len + file_slice.len + 1) return error.NameTooLong;
mem.copy(u8, &path_buf, search_path);
path_buf[search_path.len] = '/';
mem.copy(u8, path_buf[search_path.len + 1 ..], file_slice);
const path_len = search_path.len + file_slice.len + 1;
path_buf[path_len] = 0;
const full_path = path_buf[0..path_len :0].ptr;
switch (arg0_expand) {
.expand => child_argv[0] = full_path,
.no_expand => {},
}
err = execveZ(full_path, child_argv, envp);
switch (err) {
error.AccessDenied => seen_eacces = true,
error.FileNotFound, error.NotDir => {},
else => |e| return e,
}
}
if (seen_eacces) return error.AccessDenied;
return err;
}
/// Like `execvpe` except the parameters are null-terminated,
/// matching the syscall API on all targets. This removes the need for an allocator.
/// This function also uses the PATH environment variable to get the full path to the executable.
/// If `file` is an absolute path, this is the same as `execveZ`.
pub fn execvpeZ(
file: [*:0]const u8,
argv: [*:null]const ?[*:0]const u8,
envp: [*:null]const ?[*:0]const u8,
) ExecveError {
return execvpeZ_expandArg0(.no_expand, file, argv, envp);
}
/// This is the same as `execvpe` except if the `arg0_expand` parameter is set to `.expand`,
/// then argv[0] will be replaced with the expanded version of it, after resolving in accordance
/// with the PATH environment variable.
pub fn execvpe_expandArg0(
allocator: *mem.Allocator,
arg0_expand: Arg0Expand,
argv_slice: []const []const u8,
env_map: *const std.BufMap,
) (ExecveError || error{OutOfMemory}) {
const argv_buf = try allocator.alloc(?[*:0]u8, argv_slice.len + 1);
mem.set(?[*:0]u8, argv_buf, null);
defer {
for (argv_buf) |arg| {
const arg_buf = mem.spanZ(arg) orelse break;
allocator.free(arg_buf);
}
allocator.free(argv_buf);
}
for (argv_slice) |arg, i| {
const arg_buf = try allocator.alloc(u8, arg.len + 1);
@memcpy(arg_buf.ptr, arg.ptr, arg.len);
arg_buf[arg.len] = 0;
argv_buf[i] = arg_buf[0..arg.len :0].ptr;
}
argv_buf[argv_slice.len] = null;
const argv_ptr = argv_buf[0..argv_slice.len :null].ptr;
const envp_buf = try createNullDelimitedEnvMap(allocator, env_map);
defer freeNullDelimitedEnvMap(allocator, envp_buf);
switch (arg0_expand) {
.expand => return execvpeZ_expandArg0(.expand, argv_buf.ptr[0].?, argv_ptr, envp_buf.ptr),
.no_expand => return execvpeZ_expandArg0(.no_expand, argv_buf.ptr[0].?, argv_ptr, envp_buf.ptr),
}
}
/// This function must allocate memory to add a null terminating bytes on path and each arg.
/// It must also convert to KEY=VALUE\0 format for environment variables, and include null
/// pointers after the args and after the environment variables.
/// `argv_slice[0]` is the executable path.
/// This function also uses the PATH environment variable to get the full path to the executable.
pub fn execvpe(
allocator: *mem.Allocator,
argv_slice: []const []const u8,
env_map: *const std.BufMap,
) (ExecveError || error{OutOfMemory}) {
return execvpe_expandArg0(allocator, .no_expand, argv_slice, env_map);
}
pub fn createNullDelimitedEnvMap(allocator: *mem.Allocator, env_map: *const std.BufMap) ![:null]?[*:0]u8 {
const envp_count = env_map.count();
const envp_buf = try allocator.alloc(?[*:0]u8, envp_count + 1);
mem.set(?[*:0]u8, envp_buf, null);
errdefer freeNullDelimitedEnvMap(allocator, envp_buf);
{
var it = env_map.iterator();
var i: usize = 0;
while (it.next()) |pair| : (i += 1) {
const env_buf = try allocator.alloc(u8, pair.key.len + pair.value.len + 2);
@memcpy(env_buf.ptr, pair.key.ptr, pair.key.len);
env_buf[pair.key.len] = '=';
@memcpy(env_buf.ptr + pair.key.len + 1, pair.value.ptr, pair.value.len);
const len = env_buf.len - 1;
env_buf[len] = 0;
envp_buf[i] = env_buf[0..len :0].ptr;
}
assert(i == envp_count);
}
return envp_buf[0..envp_count :null];
}
pub fn freeNullDelimitedEnvMap(allocator: *mem.Allocator, envp_buf: []?[*:0]u8) void {
for (envp_buf) |env| {
const env_buf = if (env) |ptr| ptr[0 .. mem.len(ptr) + 1] else break;
allocator.free(env_buf);
}
allocator.free(envp_buf);
}
/// Get an environment variable.
/// See also `getenvZ`.
pub fn getenv(key: []const u8) ?[]const u8 {
if (builtin.link_libc) {
var small_key_buf: [64]u8 = undefined;
if (key.len < small_key_buf.len) {
mem.copy(u8, &small_key_buf, key);
small_key_buf[key.len] = 0;
const key0 = small_key_buf[0..key.len :0];
return getenvZ(key0);
}
// Search the entire `environ` because we don't have a null terminated pointer.
var ptr = std.c.environ;
while (ptr.*) |line| : (ptr += 1) {
var line_i: usize = 0;
while (line[line_i] != 0 and line[line_i] != '=') : (line_i += 1) {}
const this_key = line[0..line_i];
if (!mem.eql(u8, this_key, key)) continue;
var end_i: usize = line_i;
while (line[end_i] != 0) : (end_i += 1) {}
const value = line[line_i + 1 .. end_i];
return value;
}
return null;
}
if (builtin.os.tag == .windows) {
@compileError("std.os.getenv is unavailable for Windows because environment string is in WTF-16 format. See std.process.getEnvVarOwned for cross-platform API or std.os.getenvW for Windows-specific API.");
}
// TODO see https://github.com/ziglang/zig/issues/4524
for (environ) |ptr| {
var line_i: usize = 0;
while (ptr[line_i] != 0 and ptr[line_i] != '=') : (line_i += 1) {}
const this_key = ptr[0..line_i];
if (!mem.eql(u8, key, this_key)) continue;
var end_i: usize = line_i;
while (ptr[end_i] != 0) : (end_i += 1) {}
const this_value = ptr[line_i + 1 .. end_i];
return this_value;
}
return null;
}
pub const getenvC = @compileError("Deprecated in favor of `getenvZ`");
/// Get an environment variable with a null-terminated name.
/// See also `getenv`.
pub fn getenvZ(key: [*:0]const u8) ?[]const u8 {
if (builtin.link_libc) {
const value = system.getenv(key) orelse return null;
return mem.spanZ(value);
}
if (builtin.os.tag == .windows) {
@compileError("std.os.getenvZ is unavailable for Windows because environment string is in WTF-16 format. See std.process.getEnvVarOwned for cross-platform API or std.os.getenvW for Windows-specific API.");
}
return getenv(mem.spanZ(key));
}
/// Windows-only. Get an environment variable with a null-terminated, WTF-16 encoded name.
/// See also `getenv`.
pub fn getenvW(key: [*:0]const u16) ?[:0]const u16 {
if (builtin.os.tag != .windows) {
@compileError("std.os.getenvW is a Windows-only API");
}
const key_slice = mem.spanZ(key);
const ptr = windows.peb().ProcessParameters.Environment;
var i: usize = 0;
while (ptr[i] != 0) {
const key_start = i;
while (ptr[i] != 0 and ptr[i] != '=') : (i += 1) {}
const this_key = ptr[key_start..i];
if (ptr[i] == '=') i += 1;
const value_start = i;
while (ptr[i] != 0) : (i += 1) {}
const this_value = ptr[value_start..i :0];
if (mem.eql(u16, key_slice, this_key)) return this_value;
i += 1; // skip over null byte
}
return null;
}
pub const GetCwdError = error{
NameTooLong,
CurrentWorkingDirectoryUnlinked,
} || UnexpectedError;
/// The result is a slice of out_buffer, indexed from 0.
pub fn getcwd(out_buffer: []u8) GetCwdError![]u8 {
if (builtin.os.tag == .windows) {
return windows.GetCurrentDirectory(out_buffer);
}
const err = if (builtin.link_libc) blk: {
break :blk if (std.c.getcwd(out_buffer.ptr, out_buffer.len)) |_| 0 else std.c._errno().*;
} else blk: {
break :blk errno(system.getcwd(out_buffer.ptr, out_buffer.len));
};
switch (err) {
0 => return mem.spanZ(@ptrCast([*:0]u8, out_buffer.ptr)),
EFAULT => unreachable,
EINVAL => unreachable,
ENOENT => return error.CurrentWorkingDirectoryUnlinked,
ERANGE => return error.NameTooLong,
else => return unexpectedErrno(@intCast(usize, err)),
}
}
pub const SymLinkError = error{
AccessDenied,
DiskQuota,
PathAlreadyExists,
FileSystem,
SymLinkLoop,
FileNotFound,
SystemResources,
NoSpaceLeft,
ReadOnlyFileSystem,
NotDir,
NameTooLong,
InvalidUtf8,
BadPathName,
} || UnexpectedError;
/// Creates a symbolic link named `sym_link_path` which contains the string `target_path`.
/// A symbolic link (also known as a soft link) may point to an existing file or to a nonexistent
/// one; the latter case is known as a dangling link.
/// If `sym_link_path` exists, it will not be overwritten.
/// See also `symlinkC` and `symlinkW`.
pub fn symlink(target_path: []const u8, sym_link_path: []const u8) SymLinkError!void {
if (builtin.os.tag == .windows) {
const target_path_w = try windows.sliceToPrefixedFileW(target_path);
const sym_link_path_w = try windows.sliceToPrefixedFileW(sym_link_path);
return windows.CreateSymbolicLinkW(&sym_link_path_w, &target_path_w, 0);
} else {
const target_path_c = try toPosixPath(target_path);
const sym_link_path_c = try toPosixPath(sym_link_path);
return symlinkZ(&target_path_c, &sym_link_path_c);
}
}
pub const symlinkC = @compileError("deprecated: renamed to symlinkZ");
/// This is the same as `symlink` except the parameters are null-terminated pointers.
/// See also `symlink`.
pub fn symlinkZ(target_path: [*:0]const u8, sym_link_path: [*:0]const u8) SymLinkError!void {
if (builtin.os.tag == .windows) {
const target_path_w = try windows.cStrToPrefixedFileW(target_path);
const sym_link_path_w = try windows.cStrToPrefixedFileW(sym_link_path);
return windows.CreateSymbolicLinkW(&sym_link_path_w, &target_path_w, 0);
}
switch (errno(system.symlink(target_path, sym_link_path))) {
0 => return,
EFAULT => unreachable,
EINVAL => unreachable,
EACCES => return error.AccessDenied,
EPERM => return error.AccessDenied,
EDQUOT => return error.DiskQuota,
EEXIST => return error.PathAlreadyExists,
EIO => return error.FileSystem,
ELOOP => return error.SymLinkLoop,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOTDIR => return error.NotDir,
ENOMEM => return error.SystemResources,
ENOSPC => return error.NoSpaceLeft,
EROFS => return error.ReadOnlyFileSystem,
else => |err| return unexpectedErrno(err),
}
}
pub fn symlinkat(target_path: []const u8, newdirfd: fd_t, sym_link_path: []const u8) SymLinkError!void {
const target_path_c = try toPosixPath(target_path);
const sym_link_path_c = try toPosixPath(sym_link_path);
return symlinkatZ(target_path_c, newdirfd, sym_link_path_c);
}
pub const symlinkatC = @compileError("deprecated: renamed to symlinkatZ");
pub fn symlinkatZ(target_path: [*:0]const u8, newdirfd: fd_t, sym_link_path: [*:0]const u8) SymLinkError!void {
switch (errno(system.symlinkat(target_path, newdirfd, sym_link_path))) {
0 => return,
EFAULT => unreachable,
EINVAL => unreachable,
EACCES => return error.AccessDenied,
EPERM => return error.AccessDenied,
EDQUOT => return error.DiskQuota,
EEXIST => return error.PathAlreadyExists,
EIO => return error.FileSystem,
ELOOP => return error.SymLinkLoop,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOTDIR => return error.NotDir,
ENOMEM => return error.SystemResources,
ENOSPC => return error.NoSpaceLeft,
EROFS => return error.ReadOnlyFileSystem,
else => |err| return unexpectedErrno(err),
}
}
pub const UnlinkError = error{
FileNotFound,
AccessDenied,
FileBusy,
FileSystem,
IsDir,
SymLinkLoop,
NameTooLong,
NotDir,
SystemResources,
ReadOnlyFileSystem,
/// On Windows, file paths must be valid Unicode.
InvalidUtf8,
/// On Windows, file paths cannot contain these characters:
/// '/', '*', '?', '"', '<', '>', '|'
BadPathName,
} || UnexpectedError;
/// Delete a name and possibly the file it refers to.
/// See also `unlinkC`.
pub fn unlink(file_path: []const u8) UnlinkError!void {
if (builtin.os.tag == .windows) {
const file_path_w = try windows.sliceToPrefixedFileW(file_path);
return windows.DeleteFileW(&file_path_w);
} else {
const file_path_c = try toPosixPath(file_path);
return unlinkZ(&file_path_c);
}
}
pub const unlinkC = @compileError("deprecated: renamed to unlinkZ");
/// Same as `unlink` except the parameter is a null terminated UTF8-encoded string.
pub fn unlinkZ(file_path: [*:0]const u8) UnlinkError!void {
if (builtin.os.tag == .windows) {
const file_path_w = try windows.cStrToPrefixedFileW(file_path);
return windows.DeleteFileW(&file_path_w);
}
switch (errno(system.unlink(file_path))) {
0 => return,
EACCES => return error.AccessDenied,
EPERM => return error.AccessDenied,
EBUSY => return error.FileBusy,
EFAULT => unreachable,
EINVAL => unreachable,
EIO => return error.FileSystem,
EISDIR => return error.IsDir,
ELOOP => return error.SymLinkLoop,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOTDIR => return error.NotDir,
ENOMEM => return error.SystemResources,
EROFS => return error.ReadOnlyFileSystem,
else => |err| return unexpectedErrno(err),
}
}
pub const UnlinkatError = UnlinkError || error{
/// When passing `AT_REMOVEDIR`, this error occurs when the named directory is not empty.
DirNotEmpty,
};
/// Delete a file name and possibly the file it refers to, based on an open directory handle.
/// Asserts that the path parameter has no null bytes.
pub fn unlinkat(dirfd: fd_t, file_path: []const u8, flags: u32) UnlinkatError!void {
if (builtin.os.tag == .windows) {
const file_path_w = try windows.sliceToPrefixedFileW(file_path);
return unlinkatW(dirfd, &file_path_w, flags);
}
const file_path_c = try toPosixPath(file_path);
return unlinkatZ(dirfd, &file_path_c, flags);
}
pub const unlinkatC = @compileError("deprecated: renamed to unlinkatZ");
/// Same as `unlinkat` but `file_path` is a null-terminated string.
pub fn unlinkatZ(dirfd: fd_t, file_path_c: [*:0]const u8, flags: u32) UnlinkatError!void {
if (builtin.os.tag == .windows) {
const file_path_w = try windows.cStrToPrefixedFileW(file_path_c);
return unlinkatW(dirfd, &file_path_w, flags);
}
switch (errno(system.unlinkat(dirfd, file_path_c, flags))) {
0 => return,
EACCES => return error.AccessDenied,
EPERM => return error.AccessDenied,
EBUSY => return error.FileBusy,
EFAULT => unreachable,
EIO => return error.FileSystem,
EISDIR => return error.IsDir,
ELOOP => return error.SymLinkLoop,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOTDIR => return error.NotDir,
ENOMEM => return error.SystemResources,
EROFS => return error.ReadOnlyFileSystem,
ENOTEMPTY => return error.DirNotEmpty,
EINVAL => unreachable, // invalid flags, or pathname has . as last component
EBADF => unreachable, // always a race condition
else => |err| return unexpectedErrno(err),
}
}
/// Same as `unlinkat` but `sub_path_w` is UTF16LE, NT prefixed. Windows only.
pub fn unlinkatW(dirfd: fd_t, sub_path_w: [*:0]const u16, flags: u32) UnlinkatError!void {
const w = windows;
const want_rmdir_behavior = (flags & AT_REMOVEDIR) != 0;
const create_options_flags = if (want_rmdir_behavior)
@as(w.ULONG, w.FILE_DELETE_ON_CLOSE)
else
@as(w.ULONG, w.FILE_DELETE_ON_CLOSE | w.FILE_NON_DIRECTORY_FILE);
const path_len_bytes = @intCast(u16, mem.lenZ(sub_path_w) * 2);
var nt_name = w.UNICODE_STRING{
.Length = path_len_bytes,
.MaximumLength = path_len_bytes,
// The Windows API makes this mutable, but it will not mutate here.
.Buffer = @intToPtr([*]u16, @ptrToInt(sub_path_w)),
};
if (sub_path_w[0] == '.' and sub_path_w[1] == 0) {
// Windows does not recognize this, but it does work with empty string.
nt_name.Length = 0;
}
if (sub_path_w[0] == '.' and sub_path_w[1] == '.' and sub_path_w[2] == 0) {
// Can't remove the parent directory with an open handle.
return error.FileBusy;
}
var attr = w.OBJECT_ATTRIBUTES{
.Length = @sizeOf(w.OBJECT_ATTRIBUTES),
.RootDirectory = if (std.fs.path.isAbsoluteWindowsW(sub_path_w)) null else dirfd,
.Attributes = 0, // Note we do not use OBJ_CASE_INSENSITIVE here.
.ObjectName = &nt_name,
.SecurityDescriptor = null,
.SecurityQualityOfService = null,
};
var io: w.IO_STATUS_BLOCK = undefined;
var tmp_handle: w.HANDLE = undefined;
var rc = w.ntdll.NtCreateFile(
&tmp_handle,
w.SYNCHRONIZE | w.DELETE,
&attr,
&io,
null,
0,
w.FILE_SHARE_READ | w.FILE_SHARE_WRITE | w.FILE_SHARE_DELETE,
w.FILE_OPEN,
create_options_flags,
null,
0,
);
if (rc == .SUCCESS) {
rc = w.ntdll.NtClose(tmp_handle);
}
switch (rc) {
.SUCCESS => return,
.OBJECT_NAME_INVALID => unreachable,
.OBJECT_NAME_NOT_FOUND => return error.FileNotFound,
.INVALID_PARAMETER => unreachable,
.FILE_IS_A_DIRECTORY => return error.IsDir,
else => return w.unexpectedStatus(rc),
}
}
const RenameError = error{
AccessDenied,
FileBusy,
DiskQuota,
IsDir,
SymLinkLoop,
LinkQuotaExceeded,
NameTooLong,
FileNotFound,
NotDir,
SystemResources,
NoSpaceLeft,
PathAlreadyExists,
ReadOnlyFileSystem,
RenameAcrossMountPoints,
InvalidUtf8,
BadPathName,
NoDevice,
SharingViolation,
PipeBusy,
} || UnexpectedError;
/// Change the name or location of a file.
pub fn rename(old_path: []const u8, new_path: []const u8) RenameError!void {
if (builtin.os.tag == .windows) {
const old_path_w = try windows.sliceToPrefixedFileW(old_path);
const new_path_w = try windows.sliceToPrefixedFileW(new_path);
return renameW(&old_path_w, &new_path_w);
} else {
const old_path_c = try toPosixPath(old_path);
const new_path_c = try toPosixPath(new_path);
return renameZ(&old_path_c, &new_path_c);
}
}
pub const renameC = @compileError("deprecated: renamed to renameZ");
/// Same as `rename` except the parameters are null-terminated byte arrays.
pub fn renameZ(old_path: [*:0]const u8, new_path: [*:0]const u8) RenameError!void {
if (builtin.os.tag == .windows) {
const old_path_w = try windows.cStrToPrefixedFileW(old_path);
const new_path_w = try windows.cStrToPrefixedFileW(new_path);
return renameW(&old_path_w, &new_path_w);
}
switch (errno(system.rename(old_path, new_path))) {
0 => return,
EACCES => return error.AccessDenied,
EPERM => return error.AccessDenied,
EBUSY => return error.FileBusy,
EDQUOT => return error.DiskQuota,
EFAULT => unreachable,
EINVAL => unreachable,
EISDIR => return error.IsDir,
ELOOP => return error.SymLinkLoop,
EMLINK => return error.LinkQuotaExceeded,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOTDIR => return error.NotDir,
ENOMEM => return error.SystemResources,
ENOSPC => return error.NoSpaceLeft,
EEXIST => return error.PathAlreadyExists,
ENOTEMPTY => return error.PathAlreadyExists,
EROFS => return error.ReadOnlyFileSystem,
EXDEV => return error.RenameAcrossMountPoints,
else => |err| return unexpectedErrno(err),
}
}
/// Same as `rename` except the parameters are null-terminated UTF16LE encoded byte arrays.
/// Assumes target is Windows.
pub fn renameW(old_path: [*:0]const u16, new_path: [*:0]const u16) RenameError!void {
const flags = windows.MOVEFILE_REPLACE_EXISTING | windows.MOVEFILE_WRITE_THROUGH;
return windows.MoveFileExW(old_path, new_path, flags);
}
/// Change the name or location of a file based on an open directory handle.
pub fn renameat(
old_dir_fd: fd_t,
old_path: []const u8,
new_dir_fd: fd_t,
new_path: []const u8,
) RenameError!void {
if (builtin.os.tag == .windows) {
const old_path_w = try windows.sliceToPrefixedFileW(old_path);
const new_path_w = try windows.sliceToPrefixedFileW(new_path);
return renameatW(old_dir_fd, &old_path_w, new_dir_fd, &new_path_w, windows.TRUE);
} else {
const old_path_c = try toPosixPath(old_path);
const new_path_c = try toPosixPath(new_path);
return renameatZ(old_dir_fd, &old_path_c, new_dir_fd, &new_path_c);
}
}
/// Same as `renameat` except the parameters are null-terminated byte arrays.
pub fn renameatZ(
old_dir_fd: fd_t,
old_path: [*:0]const u8,
new_dir_fd: fd_t,
new_path: [*:0]const u8,
) RenameError!void {
if (builtin.os.tag == .windows) {
const old_path_w = try windows.cStrToPrefixedFileW(old_path);
const new_path_w = try windows.cStrToPrefixedFileW(new_path);
return renameatW(old_dir_fd, &old_path_w, new_dir_fd, &new_path_w, windows.TRUE);
}
switch (errno(system.renameat(old_dir_fd, old_path, new_dir_fd, new_path))) {
0 => return,
EACCES => return error.AccessDenied,
EPERM => return error.AccessDenied,
EBUSY => return error.FileBusy,
EDQUOT => return error.DiskQuota,
EFAULT => unreachable,
EINVAL => unreachable,
EISDIR => return error.IsDir,
ELOOP => return error.SymLinkLoop,
EMLINK => return error.LinkQuotaExceeded,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOTDIR => return error.NotDir,
ENOMEM => return error.SystemResources,
ENOSPC => return error.NoSpaceLeft,
EEXIST => return error.PathAlreadyExists,
ENOTEMPTY => return error.PathAlreadyExists,
EROFS => return error.ReadOnlyFileSystem,
EXDEV => return error.RenameAcrossMountPoints,
else => |err| return unexpectedErrno(err),
}
}
/// Same as `renameat` except the parameters are null-terminated UTF16LE encoded byte arrays.
/// Assumes target is Windows.
/// TODO these args can actually be slices when using ntdll. audit the rest of the W functions too.
pub fn renameatW(
old_dir_fd: fd_t,
old_path: [*:0]const u16,
new_dir_fd: fd_t,
new_path_w: [*:0]const u16,
ReplaceIfExists: windows.BOOLEAN,
) RenameError!void {
const access_mask = windows.SYNCHRONIZE | windows.GENERIC_WRITE | windows.DELETE;
const src_fd = try windows.OpenFileW(old_dir_fd, old_path, null, access_mask, windows.FILE_OPEN);
defer windows.CloseHandle(src_fd);
const struct_buf_len = @sizeOf(windows.FILE_RENAME_INFORMATION) + (MAX_PATH_BYTES - 1);
var rename_info_buf: [struct_buf_len]u8 align(@alignOf(windows.FILE_RENAME_INFORMATION)) = undefined;
const new_path = mem.span(new_path_w);
const struct_len = @sizeOf(windows.FILE_RENAME_INFORMATION) - 1 + new_path.len * 2;
if (struct_len > struct_buf_len) return error.NameTooLong;
const rename_info = @ptrCast(*windows.FILE_RENAME_INFORMATION, &rename_info_buf);
rename_info.* = .{
.ReplaceIfExists = ReplaceIfExists,
.RootDirectory = if (std.fs.path.isAbsoluteWindowsW(new_path_w)) null else new_dir_fd,
.FileNameLength = @intCast(u32, new_path.len * 2), // already checked error.NameTooLong
.FileName = undefined,
};
std.mem.copy(u16, @as([*]u16, &rename_info.FileName)[0..new_path.len], new_path);
var io_status_block: windows.IO_STATUS_BLOCK = undefined;
const rc = windows.ntdll.NtSetInformationFile(
src_fd,
&io_status_block,
rename_info,
@intCast(u32, struct_len), // already checked for error.NameTooLong
.FileRenameInformation,
);
switch (rc) {
.SUCCESS => return,
.INVALID_HANDLE => unreachable,
.INVALID_PARAMETER => unreachable,
.OBJECT_PATH_SYNTAX_BAD => unreachable,
.ACCESS_DENIED => return error.AccessDenied,
.OBJECT_NAME_NOT_FOUND => return error.FileNotFound,
.OBJECT_PATH_NOT_FOUND => return error.FileNotFound,
else => return windows.unexpectedStatus(rc),
}
}
pub const MakeDirError = error{
AccessDenied,
DiskQuota,
PathAlreadyExists,
SymLinkLoop,
LinkQuotaExceeded,
NameTooLong,
FileNotFound,
SystemResources,
NoSpaceLeft,
NotDir,
ReadOnlyFileSystem,
InvalidUtf8,
BadPathName,
NoDevice,
} || UnexpectedError;
pub fn mkdirat(dir_fd: fd_t, sub_dir_path: []const u8, mode: u32) MakeDirError!void {
if (builtin.os.tag == .windows) {
const sub_dir_path_w = try windows.sliceToPrefixedFileW(sub_dir_path);
return mkdiratW(dir_fd, &sub_dir_path_w, mode);
} else {
const sub_dir_path_c = try toPosixPath(sub_dir_path);
return mkdiratZ(dir_fd, &sub_dir_path_c, mode);
}
}
pub const mkdiratC = @compileError("deprecated: renamed to mkdiratZ");
pub fn mkdiratZ(dir_fd: fd_t, sub_dir_path: [*:0]const u8, mode: u32) MakeDirError!void {
if (builtin.os.tag == .windows) {
const sub_dir_path_w = try windows.cStrToPrefixedFileW(sub_dir_path);
return mkdiratW(dir_fd, &sub_dir_path_w, mode);
}
switch (errno(system.mkdirat(dir_fd, sub_dir_path, mode))) {
0 => return,
EACCES => return error.AccessDenied,
EBADF => unreachable,
EPERM => return error.AccessDenied,
EDQUOT => return error.DiskQuota,
EEXIST => return error.PathAlreadyExists,
EFAULT => unreachable,
ELOOP => return error.SymLinkLoop,
EMLINK => return error.LinkQuotaExceeded,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOMEM => return error.SystemResources,
ENOSPC => return error.NoSpaceLeft,
ENOTDIR => return error.NotDir,
EROFS => return error.ReadOnlyFileSystem,
else => |err| return unexpectedErrno(err),
}
}
pub fn mkdiratW(dir_fd: fd_t, sub_path_w: [*:0]const u16, mode: u32) MakeDirError!void {
const sub_dir_handle = try windows.CreateDirectoryW(dir_fd, sub_path_w, null);
windows.CloseHandle(sub_dir_handle);
}
/// Create a directory.
/// `mode` is ignored on Windows.
pub fn mkdir(dir_path: []const u8, mode: u32) MakeDirError!void {
if (builtin.os.tag == .windows) {
const sub_dir_handle = try windows.CreateDirectory(null, dir_path, null);
windows.CloseHandle(sub_dir_handle);
return;
} else {
const dir_path_c = try toPosixPath(dir_path);
return mkdirZ(&dir_path_c, mode);
}
}
/// Same as `mkdir` but the parameter is a null-terminated UTF8-encoded string.
pub fn mkdirZ(dir_path: [*:0]const u8, mode: u32) MakeDirError!void {
if (builtin.os.tag == .windows) {
const dir_path_w = try windows.cStrToPrefixedFileW(dir_path);
const sub_dir_handle = try windows.CreateDirectoryW(null, &dir_path_w, null);
windows.CloseHandle(sub_dir_handle);
return;
}
switch (errno(system.mkdir(dir_path, mode))) {
0 => return,
EACCES => return error.AccessDenied,
EPERM => return error.AccessDenied,
EDQUOT => return error.DiskQuota,
EEXIST => return error.PathAlreadyExists,
EFAULT => unreachable,
ELOOP => return error.SymLinkLoop,
EMLINK => return error.LinkQuotaExceeded,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOMEM => return error.SystemResources,
ENOSPC => return error.NoSpaceLeft,
ENOTDIR => return error.NotDir,
EROFS => return error.ReadOnlyFileSystem,
else => |err| return unexpectedErrno(err),
}
}
pub const DeleteDirError = error{
AccessDenied,
FileBusy,
SymLinkLoop,
NameTooLong,
FileNotFound,
SystemResources,
NotDir,
DirNotEmpty,
ReadOnlyFileSystem,
InvalidUtf8,
BadPathName,
} || UnexpectedError;
/// Deletes an empty directory.
pub fn rmdir(dir_path: []const u8) DeleteDirError!void {
if (builtin.os.tag == .windows) {
const dir_path_w = try windows.sliceToPrefixedFileW(dir_path);
return windows.RemoveDirectoryW(&dir_path_w);
} else {
const dir_path_c = try toPosixPath(dir_path);
return rmdirZ(&dir_path_c);
}
}
pub const rmdirC = @compileError("deprecated: renamed to rmdirZ");
/// Same as `rmdir` except the parameter is null-terminated.
pub fn rmdirZ(dir_path: [*:0]const u8) DeleteDirError!void {
if (builtin.os.tag == .windows) {
const dir_path_w = try windows.cStrToPrefixedFileW(dir_path);
return windows.RemoveDirectoryW(&dir_path_w);
}
switch (errno(system.rmdir(dir_path))) {
0 => return,
EACCES => return error.AccessDenied,
EPERM => return error.AccessDenied,
EBUSY => return error.FileBusy,
EFAULT => unreachable,
EINVAL => unreachable,
ELOOP => return error.SymLinkLoop,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOMEM => return error.SystemResources,
ENOTDIR => return error.NotDir,
EEXIST => return error.DirNotEmpty,
ENOTEMPTY => return error.DirNotEmpty,
EROFS => return error.ReadOnlyFileSystem,
else => |err| return unexpectedErrno(err),
}
}
pub const ChangeCurDirError = error{
AccessDenied,
FileSystem,
SymLinkLoop,
NameTooLong,
FileNotFound,
SystemResources,
NotDir,
} || UnexpectedError;
/// Changes the current working directory of the calling process.
/// `dir_path` is recommended to be a UTF-8 encoded string.
pub fn chdir(dir_path: []const u8) ChangeCurDirError!void {
if (builtin.os.tag == .windows) {
const dir_path_w = try windows.sliceToPrefixedFileW(dir_path);
@compileError("TODO implement chdir for Windows");
} else {
const dir_path_c = try toPosixPath(dir_path);
return chdirZ(&dir_path_c);
}
}
pub const chdirC = @compileError("deprecated: renamed to chdirZ");
/// Same as `chdir` except the parameter is null-terminated.
pub fn chdirZ(dir_path: [*:0]const u8) ChangeCurDirError!void {
if (builtin.os.tag == .windows) {
const dir_path_w = try windows.cStrToPrefixedFileW(dir_path);
@compileError("TODO implement chdir for Windows");
}
switch (errno(system.chdir(dir_path))) {
0 => return,
EACCES => return error.AccessDenied,
EFAULT => unreachable,
EIO => return error.FileSystem,
ELOOP => return error.SymLinkLoop,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOMEM => return error.SystemResources,
ENOTDIR => return error.NotDir,
else => |err| return unexpectedErrno(err),
}
}
pub const FchdirError = error{
AccessDenied,
NotDir,
FileSystem,
} || UnexpectedError;
pub fn fchdir(dirfd: fd_t) FchdirError!void {
while (true) {
switch (errno(system.fchdir(dirfd))) {
0 => return,
EACCES => return error.AccessDenied,
EBADF => unreachable,
ENOTDIR => return error.NotDir,
EINTR => continue,
EIO => return error.FileSystem,
else => |err| return unexpectedErrno(err),
}
}
}
pub const ReadLinkError = error{
AccessDenied,
FileSystem,
SymLinkLoop,
NameTooLong,
FileNotFound,
SystemResources,
NotDir,
} || UnexpectedError;
/// Read value of a symbolic link.
/// The return value is a slice of `out_buffer` from index 0.
pub fn readlink(file_path: []const u8, out_buffer: []u8) ReadLinkError![]u8 {
if (builtin.os.tag == .windows) {
const file_path_w = try windows.sliceToPrefixedFileW(file_path);
@compileError("TODO implement readlink for Windows");
} else {
const file_path_c = try toPosixPath(file_path);
return readlinkZ(&file_path_c, out_buffer);
}
}
pub const readlinkC = @compileError("deprecated: renamed to readlinkZ");
/// Same as `readlink` except `file_path` is null-terminated.
pub fn readlinkZ(file_path: [*:0]const u8, out_buffer: []u8) ReadLinkError![]u8 {
if (builtin.os.tag == .windows) {
const file_path_w = try windows.cStrToPrefixedFileW(file_path);
@compileError("TODO implement readlink for Windows");
}
const rc = system.readlink(file_path, out_buffer.ptr, out_buffer.len);
switch (errno(rc)) {
0 => return out_buffer[0..@bitCast(usize, rc)],
EACCES => return error.AccessDenied,
EFAULT => unreachable,
EINVAL => unreachable,
EIO => return error.FileSystem,
ELOOP => return error.SymLinkLoop,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOMEM => return error.SystemResources,
ENOTDIR => return error.NotDir,
else => |err| return unexpectedErrno(err),
}
}
pub const readlinkatC = @compileError("deprecated: renamed to readlinkatZ");
pub fn readlinkatZ(dirfd: fd_t, file_path: [*:0]const u8, out_buffer: []u8) ReadLinkError![]u8 {
if (builtin.os.tag == .windows) {
const file_path_w = try windows.cStrToPrefixedFileW(file_path);
@compileError("TODO implement readlink for Windows");
}
const rc = system.readlinkat(dirfd, file_path, out_buffer.ptr, out_buffer.len);
switch (errno(rc)) {
0 => return out_buffer[0..@bitCast(usize, rc)],
EACCES => return error.AccessDenied,
EFAULT => unreachable,
EINVAL => unreachable,
EIO => return error.FileSystem,
ELOOP => return error.SymLinkLoop,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOMEM => return error.SystemResources,
ENOTDIR => return error.NotDir,
else => |err| return unexpectedErrno(err),
}
}
pub const SetIdError = error{
ResourceLimitReached,
InvalidUserId,
PermissionDenied,
} || UnexpectedError;
pub fn setuid(uid: u32) SetIdError!void {
switch (errno(system.setuid(uid))) {
0 => return,
EAGAIN => return error.ResourceLimitReached,
EINVAL => return error.InvalidUserId,
EPERM => return error.PermissionDenied,
else => |err| return unexpectedErrno(err),
}
}
pub fn setreuid(ruid: u32, euid: u32) SetIdError!void {
switch (errno(system.setreuid(ruid, euid))) {
0 => return,
EAGAIN => return error.ResourceLimitReached,
EINVAL => return error.InvalidUserId,
EPERM => return error.PermissionDenied,
else => |err| return unexpectedErrno(err),
}
}
pub fn setgid(gid: u32) SetIdError!void {
switch (errno(system.setgid(gid))) {
0 => return,
EAGAIN => return error.ResourceLimitReached,
EINVAL => return error.InvalidUserId,
EPERM => return error.PermissionDenied,
else => |err| return unexpectedErrno(err),
}
}
pub fn setregid(rgid: u32, egid: u32) SetIdError!void {
switch (errno(system.setregid(rgid, egid))) {
0 => return,
EAGAIN => return error.ResourceLimitReached,
EINVAL => return error.InvalidUserId,
EPERM => return error.PermissionDenied,
else => |err| return unexpectedErrno(err),
}
}
/// Test whether a file descriptor refers to a terminal.
pub fn isatty(handle: fd_t) bool {
if (builtin.os.tag == .windows) {
if (isCygwinPty(handle))
return true;
var out: windows.DWORD = undefined;
return windows.kernel32.GetConsoleMode(handle, &out) != 0;
}
if (builtin.link_libc) {
return system.isatty(handle) != 0;
}
if (builtin.os.tag == .wasi) {
var statbuf: fdstat_t = undefined;
const err = system.fd_fdstat_get(handle, &statbuf);
if (err != 0) {
// errno = err;
return false;
}
// A tty is a character device that we can't seek or tell on.
if (statbuf.fs_filetype != FILETYPE_CHARACTER_DEVICE or
(statbuf.fs_rights_base & (RIGHT_FD_SEEK | RIGHT_FD_TELL)) != 0)
{
// errno = ENOTTY;
return false;
}
return true;
}
if (builtin.os.tag == .linux) {
var wsz: linux.winsize = undefined;
return linux.syscall3(.ioctl, @bitCast(usize, @as(isize, handle)), linux.TIOCGWINSZ, @ptrToInt(&wsz)) == 0;
}
unreachable;
}
pub fn isCygwinPty(handle: fd_t) bool {
if (builtin.os.tag != .windows) return false;
const size = @sizeOf(windows.FILE_NAME_INFO);
var name_info_bytes align(@alignOf(windows.FILE_NAME_INFO)) = [_]u8{0} ** (size + windows.MAX_PATH);
if (windows.kernel32.GetFileInformationByHandleEx(
handle,
windows.FileNameInfo,
@ptrCast(*c_void, &name_info_bytes),
name_info_bytes.len,
) == 0) {
return false;
}
const name_info = @ptrCast(*const windows.FILE_NAME_INFO, &name_info_bytes[0]);
const name_bytes = name_info_bytes[size .. size + @as(usize, name_info.FileNameLength)];
const name_wide = mem.bytesAsSlice(u16, name_bytes);
return mem.indexOf(u16, name_wide, &[_]u16{ 'm', 's', 'y', 's', '-' }) != null or
mem.indexOf(u16, name_wide, &[_]u16{ '-', 'p', 't', 'y' }) != null;
}
pub const SocketError = error{
/// Permission to create a socket of the specified type and/or
/// pro‐tocol is denied.
PermissionDenied,
/// The implementation does not support the specified address family.
AddressFamilyNotSupported,
/// Unknown protocol, or protocol family not available.
ProtocolFamilyNotAvailable,
/// The per-process limit on the number of open file descriptors has been reached.
ProcessFdQuotaExceeded,
/// The system-wide limit on the total number of open files has been reached.
SystemFdQuotaExceeded,
/// Insufficient memory is available. The socket cannot be created until sufficient
/// resources are freed.
SystemResources,
/// The protocol type or the specified protocol is not supported within this domain.
ProtocolNotSupported,
} || UnexpectedError;
pub fn socket(domain: u32, socket_type: u32, protocol: u32) SocketError!fd_t {
const rc = system.socket(domain, socket_type, protocol);
switch (errno(rc)) {
0 => return @intCast(fd_t, rc),
EACCES => return error.PermissionDenied,
EAFNOSUPPORT => return error.AddressFamilyNotSupported,
EINVAL => return error.ProtocolFamilyNotAvailable,
EMFILE => return error.ProcessFdQuotaExceeded,
ENFILE => return error.SystemFdQuotaExceeded,
ENOBUFS => return error.SystemResources,
ENOMEM => return error.SystemResources,
EPROTONOSUPPORT => return error.ProtocolNotSupported,
else => |err| return unexpectedErrno(err),
}
}
pub const BindError = error{
/// The address is protected, and the user is not the superuser.
/// For UNIX domain sockets: Search permission is denied on a component
/// of the path prefix.
AccessDenied,
/// The given address is already in use, or in the case of Internet domain sockets,
/// The port number was specified as zero in the socket
/// address structure, but, upon attempting to bind to an ephemeral port, it was
/// determined that all port numbers in the ephemeral port range are currently in
/// use. See the discussion of /proc/sys/net/ipv4/ip_local_port_range ip(7).
AddressInUse,
/// A nonexistent interface was requested or the requested address was not local.
AddressNotAvailable,
/// Too many symbolic links were encountered in resolving addr.
SymLinkLoop,
/// addr is too long.
NameTooLong,
/// A component in the directory prefix of the socket pathname does not exist.
FileNotFound,
/// Insufficient kernel memory was available.
SystemResources,
/// A component of the path prefix is not a directory.
NotDir,
/// The socket inode would reside on a read-only filesystem.
ReadOnlyFileSystem,
} || UnexpectedError;
/// addr is `*const T` where T is one of the sockaddr
pub fn bind(sockfd: fd_t, addr: *const sockaddr, len: socklen_t) BindError!void {
const rc = system.bind(sockfd, addr, len);
switch (errno(rc)) {
0 => return,
EACCES => return error.AccessDenied,
EADDRINUSE => return error.AddressInUse,
EBADF => unreachable, // always a race condition if this error is returned
EINVAL => unreachable, // invalid parameters
ENOTSOCK => unreachable, // invalid `sockfd`
EADDRNOTAVAIL => return error.AddressNotAvailable,
EFAULT => unreachable, // invalid `addr` pointer
ELOOP => return error.SymLinkLoop,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOMEM => return error.SystemResources,
ENOTDIR => return error.NotDir,
EROFS => return error.ReadOnlyFileSystem,
else => |err| return unexpectedErrno(err),
}
}
const ListenError = error{
/// Another socket is already listening on the same port.
/// For Internet domain sockets, the socket referred to by sockfd had not previously
/// been bound to an address and, upon attempting to bind it to an ephemeral port, it
/// was determined that all port numbers in the ephemeral port range are currently in
/// use. See the discussion of /proc/sys/net/ipv4/ip_local_port_range in ip(7).
AddressInUse,
/// The file descriptor sockfd does not refer to a socket.
FileDescriptorNotASocket,
/// The socket is not of a type that supports the listen() operation.
OperationNotSupported,
} || UnexpectedError;
pub fn listen(sockfd: fd_t, backlog: u32) ListenError!void {
const rc = system.listen(sockfd, backlog);
switch (errno(rc)) {
0 => return,
EADDRINUSE => return error.AddressInUse,
EBADF => unreachable,
ENOTSOCK => return error.FileDescriptorNotASocket,
EOPNOTSUPP => return error.OperationNotSupported,
else => |err| return unexpectedErrno(err),
}
}
pub const AcceptError = error{
ConnectionAborted,
/// The per-process limit on the number of open file descriptors has been reached.
ProcessFdQuotaExceeded,
/// The system-wide limit on the total number of open files has been reached.
SystemFdQuotaExceeded,
/// Not enough free memory. This often means that the memory allocation is limited
/// by the socket buffer limits, not by the system memory.
SystemResources,
ProtocolFailure,
/// Firewall rules forbid connection.
BlockedByFirewall,
/// This error occurs when no global event loop is configured,
/// and accepting from the socket would block.
WouldBlock,
} || UnexpectedError;
/// Accept a connection on a socket.
/// If the application has a global event loop enabled, EAGAIN is handled
/// via the event loop. Otherwise EAGAIN results in error.WouldBlock.
pub fn accept4(
/// This argument is a socket that has been created with `socket`, bound to a local address
/// with `bind`, and is listening for connections after a `listen`.
sockfd: fd_t,
/// This argument is a pointer to a sockaddr structure. This structure is filled in with the
/// address of the peer socket, as known to the communications layer. The exact format of the
/// address returned addr is determined by the socket's address family (see `socket` and the
/// respective protocol man pages).
addr: *sockaddr,
/// This argument is a value-result argument: the caller must initialize it to contain the
/// size (in bytes) of the structure pointed to by addr; on return it will contain the actual size
/// of the peer address.
///
/// The returned address is truncated if the buffer provided is too small; in this case, `addr_size`
/// will return a value greater than was supplied to the call.
addr_size: *socklen_t,
/// If flags is 0, then `accept4` is the same as `accept`. The following values can be bitwise
/// ORed in flags to obtain different behavior:
/// * `SOCK_NONBLOCK` - Set the `O_NONBLOCK` file status flag on the open file description (see `open`)
/// referred to by the new file descriptor. Using this flag saves extra calls to `fcntl` to achieve
/// the same result.
/// * `SOCK_CLOEXEC` - Set the close-on-exec (`FD_CLOEXEC`) flag on the new file descriptor. See the
/// description of the `O_CLOEXEC` flag in `open` for reasons why this may be useful.
flags: u32,
) AcceptError!fd_t {
while (true) {
const rc = system.accept4(sockfd, addr, addr_size, flags);
switch (errno(rc)) {
0 => return @intCast(fd_t, rc),
EINTR => continue,
EAGAIN => if (std.event.Loop.instance) |loop| {
loop.waitUntilFdReadable(sockfd);
continue;
} else {
return error.WouldBlock;
},
EBADF => unreachable, // always a race condition
ECONNABORTED => return error.ConnectionAborted,
EFAULT => unreachable,
EINVAL => unreachable,
ENOTSOCK => unreachable,
EMFILE => return error.ProcessFdQuotaExceeded,
ENFILE => return error.SystemFdQuotaExceeded,
ENOBUFS => return error.SystemResources,
ENOMEM => return error.SystemResources,
EOPNOTSUPP => unreachable,
EPROTO => return error.ProtocolFailure,
EPERM => return error.BlockedByFirewall,
else => |err| return unexpectedErrno(err),
}
}
}
pub const EpollCreateError = error{
/// The per-user limit on the number of epoll instances imposed by
/// /proc/sys/fs/epoll/max_user_instances was encountered. See epoll(7) for further
/// details.
/// Or, The per-process limit on the number of open file descriptors has been reached.
ProcessFdQuotaExceeded,
/// The system-wide limit on the total number of open files has been reached.
SystemFdQuotaExceeded,
/// There was insufficient memory to create the kernel object.
SystemResources,
} || UnexpectedError;
pub fn epoll_create1(flags: u32) EpollCreateError!i32 {
const rc = system.epoll_create1(flags);
switch (errno(rc)) {
0 => return @intCast(i32, rc),
else => |err| return unexpectedErrno(err),
EINVAL => unreachable,
EMFILE => return error.ProcessFdQuotaExceeded,
ENFILE => return error.SystemFdQuotaExceeded,
ENOMEM => return error.SystemResources,
}
}
pub const EpollCtlError = error{
/// op was EPOLL_CTL_ADD, and the supplied file descriptor fd is already registered
/// with this epoll instance.
FileDescriptorAlreadyPresentInSet,
/// fd refers to an epoll instance and this EPOLL_CTL_ADD operation would result in a
/// circular loop of epoll instances monitoring one another.
OperationCausesCircularLoop,
/// op was EPOLL_CTL_MOD or EPOLL_CTL_DEL, and fd is not registered with this epoll
/// instance.
FileDescriptorNotRegistered,
/// There was insufficient memory to handle the requested op control operation.
SystemResources,
/// The limit imposed by /proc/sys/fs/epoll/max_user_watches was encountered while
/// trying to register (EPOLL_CTL_ADD) a new file descriptor on an epoll instance.
/// See epoll(7) for further details.
UserResourceLimitReached,
/// The target file fd does not support epoll. This error can occur if fd refers to,
/// for example, a regular file or a directory.
FileDescriptorIncompatibleWithEpoll,
} || UnexpectedError;
pub fn epoll_ctl(epfd: i32, op: u32, fd: i32, event: ?*epoll_event) EpollCtlError!void {
const rc = system.epoll_ctl(epfd, op, fd, event);
switch (errno(rc)) {
0 => return,
else => |err| return unexpectedErrno(err),
EBADF => unreachable, // always a race condition if this happens
EEXIST => return error.FileDescriptorAlreadyPresentInSet,
EINVAL => unreachable,
ELOOP => return error.OperationCausesCircularLoop,
ENOENT => return error.FileDescriptorNotRegistered,
ENOMEM => return error.SystemResources,
ENOSPC => return error.UserResourceLimitReached,
EPERM => return error.FileDescriptorIncompatibleWithEpoll,
}
}
/// Waits for an I/O event on an epoll file descriptor.
/// Returns the number of file descriptors ready for the requested I/O,
/// or zero if no file descriptor became ready during the requested timeout milliseconds.
pub fn epoll_wait(epfd: i32, events: []epoll_event, timeout: i32) usize {
while (true) {
// TODO get rid of the @intCast
const rc = system.epoll_wait(epfd, events.ptr, @intCast(u32, events.len), timeout);
switch (errno(rc)) {
0 => return @intCast(usize, rc),
EINTR => continue,
EBADF => unreachable,
EFAULT => unreachable,
EINVAL => unreachable,
else => unreachable,
}
}
}
pub const EventFdError = error{
SystemResources,
ProcessFdQuotaExceeded,
SystemFdQuotaExceeded,
} || UnexpectedError;
pub fn eventfd(initval: u32, flags: u32) EventFdError!i32 {
const rc = system.eventfd(initval, flags);
switch (errno(rc)) {
0 => return @intCast(i32, rc),
else => |err| return unexpectedErrno(err),
EINVAL => unreachable, // invalid parameters
EMFILE => return error.ProcessFdQuotaExceeded,
ENFILE => return error.SystemFdQuotaExceeded,
ENODEV => return error.SystemResources,
ENOMEM => return error.SystemResources,
}
}
pub const GetSockNameError = error{
/// Insufficient resources were available in the system to perform the operation.
SystemResources,
} || UnexpectedError;
pub fn getsockname(sockfd: fd_t, addr: *sockaddr, addrlen: *socklen_t) GetSockNameError!void {
switch (errno(system.getsockname(sockfd, addr, addrlen))) {
0 => return,
else => |err| return unexpectedErrno(err),
EBADF => unreachable, // always a race condition
EFAULT => unreachable,
EINVAL => unreachable, // invalid parameters
ENOTSOCK => unreachable,
ENOBUFS => return error.SystemResources,
}
}
pub const ConnectError = error{
/// For UNIX domain sockets, which are identified by pathname: Write permission is denied on the socket
/// file, or search permission is denied for one of the directories in the path prefix.
/// or
/// The user tried to connect to a broadcast address without having the socket broadcast flag enabled or
/// the connection request failed because of a local firewall rule.
PermissionDenied,
/// Local address is already in use.
AddressInUse,
/// (Internet domain sockets) The socket referred to by sockfd had not previously been bound to an
/// address and, upon attempting to bind it to an ephemeral port, it was determined that all port numbers
/// in the ephemeral port range are currently in use. See the discussion of
/// /proc/sys/net/ipv4/ip_local_port_range in ip(7).
AddressNotAvailable,
/// The passed address didn't have the correct address family in its sa_family field.
AddressFamilyNotSupported,
/// Insufficient entries in the routing cache.
SystemResources,
/// A connect() on a stream socket found no one listening on the remote address.
ConnectionRefused,
/// Network is unreachable.
NetworkUnreachable,
/// Timeout while attempting connection. The server may be too busy to accept new connections. Note
/// that for IP sockets the timeout may be very long when syncookies are enabled on the server.
ConnectionTimedOut,
/// This error occurs when no global event loop is configured,
/// and connecting to the socket would block.
WouldBlock,
/// The given path for the unix socket does not exist.
FileNotFound,
} || UnexpectedError;
/// Initiate a connection on a socket.
pub fn connect(sockfd: fd_t, sock_addr: *const sockaddr, len: socklen_t) ConnectError!void {
while (true) {
switch (errno(system.connect(sockfd, sock_addr, len))) {
0 => return,
EACCES => return error.PermissionDenied,
EPERM => return error.PermissionDenied,
EADDRINUSE => return error.AddressInUse,
EADDRNOTAVAIL => return error.AddressNotAvailable,
EAFNOSUPPORT => return error.AddressFamilyNotSupported,
EAGAIN, EINPROGRESS => {
const loop = std.event.Loop.instance orelse return error.WouldBlock;
loop.waitUntilFdWritableOrReadable(sockfd);
return getsockoptError(sockfd);
},
EALREADY => unreachable, // The socket is nonblocking and a previous connection attempt has not yet been completed.
EBADF => unreachable, // sockfd is not a valid open file descriptor.
ECONNREFUSED => return error.ConnectionRefused,
EFAULT => unreachable, // The socket structure address is outside the user's address space.
EINTR => continue,
EISCONN => unreachable, // The socket is already connected.
ENETUNREACH => return error.NetworkUnreachable,
ENOTSOCK => unreachable, // The file descriptor sockfd does not refer to a socket.
EPROTOTYPE => unreachable, // The socket type does not support the requested communications protocol.
ETIMEDOUT => return error.ConnectionTimedOut,
ENOENT => return error.FileNotFound, // Returned when socket is AF_UNIX and the given path does not exist.
else => |err| return unexpectedErrno(err),
}
}
}
pub fn getsockoptError(sockfd: fd_t) ConnectError!void {
var err_code: u32 = undefined;
var size: u32 = @sizeOf(u32);
const rc = system.getsockopt(sockfd, SOL_SOCKET, SO_ERROR, @ptrCast([*]u8, &err_code), &size);
assert(size == 4);
switch (errno(rc)) {
0 => switch (err_code) {
0 => return,
EACCES => return error.PermissionDenied,
EPERM => return error.PermissionDenied,
EADDRINUSE => return error.AddressInUse,
EADDRNOTAVAIL => return error.AddressNotAvailable,
EAFNOSUPPORT => return error.AddressFamilyNotSupported,
EAGAIN => return error.SystemResources,
EALREADY => unreachable, // The socket is nonblocking and a previous connection attempt has not yet been completed.
EBADF => unreachable, // sockfd is not a valid open file descriptor.
ECONNREFUSED => return error.ConnectionRefused,
EFAULT => unreachable, // The socket structure address is outside the user's address space.
EISCONN => unreachable, // The socket is already connected.
ENETUNREACH => return error.NetworkUnreachable,
ENOTSOCK => unreachable, // The file descriptor sockfd does not refer to a socket.
EPROTOTYPE => unreachable, // The socket type does not support the requested communications protocol.
ETIMEDOUT => return error.ConnectionTimedOut,
else => |err| return unexpectedErrno(err),
},
EBADF => unreachable, // The argument sockfd is not a valid file descriptor.
EFAULT => unreachable, // The address pointed to by optval or optlen is not in a valid part of the process address space.
EINVAL => unreachable,
ENOPROTOOPT => unreachable, // The option is unknown at the level indicated.
ENOTSOCK => unreachable, // The file descriptor sockfd does not refer to a socket.
else => |err| return unexpectedErrno(err),
}
}
pub fn waitpid(pid: i32, flags: u32) u32 {
// TODO allow implicit pointer cast from *u32 to *c_uint ?
const Status = if (builtin.link_libc) c_uint else u32;
var status: Status = undefined;
while (true) {
switch (errno(system.waitpid(pid, &status, flags))) {
0 => return @bitCast(u32, status),
EINTR => continue,
ECHILD => unreachable, // The process specified does not exist. It would be a race condition to handle this error.
EINVAL => unreachable, // The options argument was invalid
else => unreachable,
}
}
}
pub const FStatError = error{
SystemResources,
AccessDenied,
} || UnexpectedError;
pub fn fstat(fd: fd_t) FStatError!Stat {
var stat: Stat = undefined;
switch (errno(system.fstat(fd, &stat))) {
0 => return stat,
EINVAL => unreachable,
EBADF => unreachable, // Always a race condition.
ENOMEM => return error.SystemResources,
EACCES => return error.AccessDenied,
else => |err| return unexpectedErrno(err),
}
}
const FStatAtError = FStatError || error{NameTooLong};
pub fn fstatat(dirfd: fd_t, pathname: []const u8, flags: u32) FStatAtError![]Stat {
const pathname_c = try toPosixPath(pathname);
return fstatatZ(dirfd, &pathname_c, flags);
}
pub const fstatatC = @compileError("deprecated: renamed to fstatatZ");
pub fn fstatatZ(dirfd: fd_t, pathname: [*:0]const u8, flags: u32) FStatAtError!Stat {
var stat: Stat = undefined;
switch (errno(system.fstatat(dirfd, pathname, &stat, flags))) {
0 => return stat,
EINVAL => unreachable,
EBADF => unreachable, // Always a race condition.
ENOMEM => return error.SystemResources,
EACCES => return error.AccessDenied,
EFAULT => unreachable,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOTDIR => return error.FileNotFound,
else => |err| return unexpectedErrno(err),
}
}
pub const KQueueError = error{
/// The per-process limit on the number of open file descriptors has been reached.
ProcessFdQuotaExceeded,
/// The system-wide limit on the total number of open files has been reached.
SystemFdQuotaExceeded,
} || UnexpectedError;
pub fn kqueue() KQueueError!i32 {
const rc = system.kqueue();
switch (errno(rc)) {
0 => return @intCast(i32, rc),
EMFILE => return error.ProcessFdQuotaExceeded,
ENFILE => return error.SystemFdQuotaExceeded,
else => |err| return unexpectedErrno(err),
}
}
pub const KEventError = error{
/// The process does not have permission to register a filter.
AccessDenied,
/// The event could not be found to be modified or deleted.
EventNotFound,
/// No memory was available to register the event.
SystemResources,
/// The specified process to attach to does not exist.
ProcessNotFound,
/// changelist or eventlist had too many items on it.
/// TODO remove this possibility
Overflow,
};
pub fn kevent(
kq: i32,
changelist: []const Kevent,
eventlist: []Kevent,
timeout: ?*const timespec,
) KEventError!usize {
while (true) {
const rc = system.kevent(
kq,
changelist.ptr,
try math.cast(c_int, changelist.len),
eventlist.ptr,
try math.cast(c_int, eventlist.len),
timeout,
);
switch (errno(rc)) {
0 => return @intCast(usize, rc),
EACCES => return error.AccessDenied,
EFAULT => unreachable,
EBADF => unreachable, // Always a race condition.
EINTR => continue,
EINVAL => unreachable,
ENOENT => return error.EventNotFound,
ENOMEM => return error.SystemResources,
ESRCH => return error.ProcessNotFound,
else => unreachable,
}
}
}
pub const INotifyInitError = error{
ProcessFdQuotaExceeded,
SystemFdQuotaExceeded,
SystemResources,
} || UnexpectedError;
/// initialize an inotify instance
pub fn inotify_init1(flags: u32) INotifyInitError!i32 {
const rc = system.inotify_init1(flags);
switch (errno(rc)) {
0 => return @intCast(i32, rc),
EINVAL => unreachable,
EMFILE => return error.ProcessFdQuotaExceeded,
ENFILE => return error.SystemFdQuotaExceeded,
ENOMEM => return error.SystemResources,
else => |err| return unexpectedErrno(err),
}
}
pub const INotifyAddWatchError = error{
AccessDenied,
NameTooLong,
FileNotFound,
SystemResources,
UserResourceLimitReached,
} || UnexpectedError;
/// add a watch to an initialized inotify instance
pub fn inotify_add_watch(inotify_fd: i32, pathname: []const u8, mask: u32) INotifyAddWatchError!i32 {
const pathname_c = try toPosixPath(pathname);
return inotify_add_watchZ(inotify_fd, &pathname_c, mask);
}
pub const inotify_add_watchC = @compileError("deprecated: renamed to inotify_add_watchZ");
/// Same as `inotify_add_watch` except pathname is null-terminated.
pub fn inotify_add_watchZ(inotify_fd: i32, pathname: [*:0]const u8, mask: u32) INotifyAddWatchError!i32 {
const rc = system.inotify_add_watch(inotify_fd, pathname, mask);
switch (errno(rc)) {
0 => return @intCast(i32, rc),
EACCES => return error.AccessDenied,
EBADF => unreachable,
EFAULT => unreachable,
EINVAL => unreachable,
ENAMETOOLONG => return error.NameTooLong,
ENOENT => return error.FileNotFound,
ENOMEM => return error.SystemResources,
ENOSPC => return error.UserResourceLimitReached,
else => |err| return unexpectedErrno(err),
}
}
/// remove an existing watch from an inotify instance
pub fn inotify_rm_watch(inotify_fd: i32, wd: i32) void {
switch (errno(system.inotify_rm_watch(inotify_fd, wd))) {
0 => return,
EBADF => unreachable,
EINVAL => unreachable,
else => unreachable,
}
}
pub const MProtectError = error{
/// The memory cannot be given the specified access. This can happen, for example, if you
/// mmap(2) a file to which you have read-only access, then ask mprotect() to mark it
/// PROT_WRITE.
AccessDenied,
/// Changing the protection of a memory region would result in the total number of map‐
/// pings with distinct attributes (e.g., read versus read/write protection) exceeding the
/// allowed maximum. (For example, making the protection of a range PROT_READ in the mid‐
/// dle of a region currently protected as PROT_READ|PROT_WRITE would result in three map‐
/// pings: two read/write mappings at each end and a read-only mapping in the middle.)
OutOfMemory,
} || UnexpectedError;
/// `memory.len` must be page-aligned.
pub fn mprotect(memory: []align(mem.page_size) u8, protection: u32) MProtectError!void {
assert(mem.isAligned(memory.len, mem.page_size));
switch (errno(system.mprotect(memory.ptr, memory.len, protection))) {
0 => return,
EINVAL => unreachable,
EACCES => return error.AccessDenied,
ENOMEM => return error.OutOfMemory,
else => |err| return unexpectedErrno(err),
}
}
pub const ForkError = error{SystemResources} || UnexpectedError;
pub fn fork() ForkError!pid_t {
const rc = system.fork();
switch (errno(rc)) {
0 => return @intCast(pid_t, rc),
EAGAIN => return error.SystemResources,
ENOMEM => return error.SystemResources,
else => |err| return unexpectedErrno(err),
}
}
pub const MMapError = error{
/// The underlying filesystem of the specified file does not support memory mapping.
MemoryMappingNotSupported,
/// A file descriptor refers to a non-regular file. Or a file mapping was requested,
/// but the file descriptor is not open for reading. Or `MAP_SHARED` was requested
/// and `PROT_WRITE` is set, but the file descriptor is not open in `O_RDWR` mode.
/// Or `PROT_WRITE` is set, but the file is append-only.
AccessDenied,
/// The `prot` argument asks for `PROT_EXEC` but the mapped area belongs to a file on
/// a filesystem that was mounted no-exec.
PermissionDenied,
LockedMemoryLimitExceeded,
OutOfMemory,
} || UnexpectedError;
/// Map files or devices into memory.
/// `length` does not need to be aligned.
/// Use of a mapped region can result in these signals:
/// * SIGSEGV - Attempted write into a region mapped as read-only.
/// * SIGBUS - Attempted access to a portion of the buffer that does not correspond to the file
pub fn mmap(
ptr: ?[*]align(mem.page_size) u8,
length: usize,
prot: u32,
flags: u32,
fd: fd_t,
offset: u64,
) MMapError![]align(mem.page_size) u8 {
const err = if (builtin.link_libc) blk: {
const rc = std.c.mmap(ptr, length, prot, flags, fd, offset);
if (rc != std.c.MAP_FAILED) return @ptrCast([*]align(mem.page_size) u8, @alignCast(mem.page_size, rc))[0..length];
break :blk @intCast(usize, system._errno().*);
} else blk: {
const rc = system.mmap(ptr, length, prot, flags, fd, offset);
const err = errno(rc);
if (err == 0) return @intToPtr([*]align(mem.page_size) u8, rc)[0..length];
break :blk err;
};
switch (err) {
ETXTBSY => return error.AccessDenied,
EACCES => return error.AccessDenied,
EPERM => return error.PermissionDenied,
EAGAIN => return error.LockedMemoryLimitExceeded,
EBADF => unreachable, // Always a race condition.
EOVERFLOW => unreachable, // The number of pages used for length + offset would overflow.
ENODEV => return error.MemoryMappingNotSupported,
EINVAL => unreachable, // Invalid parameters to mmap()
ENOMEM => return error.OutOfMemory,
else => return unexpectedErrno(err),
}
}
/// Deletes the mappings for the specified address range, causing
/// further references to addresses within the range to generate invalid memory references.
/// Note that while POSIX allows unmapping a region in the middle of an existing mapping,
/// Zig's munmap function does not, for two reasons:
/// * It violates the Zig principle that resource deallocation must succeed.
/// * The Windows function, VirtualFree, has this restriction.
pub fn munmap(memory: []align(mem.page_size) u8) void {
switch (errno(system.munmap(memory.ptr, memory.len))) {
0 => return,
EINVAL => unreachable, // Invalid parameters.
ENOMEM => unreachable, // Attempted to unmap a region in the middle of an existing mapping.
else => unreachable,
}
}
pub const AccessError = error{
PermissionDenied,
FileNotFound,
NameTooLong,
InputOutput,
SystemResources,
BadPathName,
FileBusy,
SymLinkLoop,
ReadOnlyFileSystem,
/// On Windows, file paths must be valid Unicode.
InvalidUtf8,
} || UnexpectedError;
/// check user's permissions for a file
/// TODO currently this assumes `mode` is `F_OK` on Windows.
pub fn access(path: []const u8, mode: u32) AccessError!void {
if (builtin.os.tag == .windows) {
const path_w = try windows.sliceToPrefixedFileW(path);
_ = try windows.GetFileAttributesW(&path_w);
return;
}
const path_c = try toPosixPath(path);
return accessZ(&path_c, mode);
}
pub const accessC = @compileError("Deprecated in favor of `accessZ`");
/// Same as `access` except `path` is null-terminated.
pub fn accessZ(path: [*:0]const u8, mode: u32) AccessError!void {
if (builtin.os.tag == .windows) {
const path_w = try windows.cStrToPrefixedFileW(path);
_ = try windows.GetFileAttributesW(&path_w);
return;
}
switch (errno(system.access(path, mode))) {
0 => return,
EACCES => return error.PermissionDenied,
EROFS => return error.ReadOnlyFileSystem,
ELOOP => return error.SymLinkLoop,
ETXTBSY => return error.FileBusy,
ENOTDIR => return error.FileNotFound,
ENOENT => return error.FileNotFound,
ENAMETOOLONG => return error.NameTooLong,
EINVAL => unreachable,
EFAULT => unreachable,
EIO => return error.InputOutput,
ENOMEM => return error.SystemResources,
else => |err| return unexpectedErrno(err),
}
}
/// Call from Windows-specific code if you already have a UTF-16LE encoded, null terminated string.
/// Otherwise use `access` or `accessC`.
/// TODO currently this ignores `mode`.
pub fn accessW(path: [*:0]const u16, mode: u32) windows.GetFileAttributesError!void {
const ret = try windows.GetFileAttributesW(path);
if (ret != windows.INVALID_FILE_ATTRIBUTES) {
return;
}
switch (windows.kernel32.GetLastError()) {
.FILE_NOT_FOUND => return error.FileNotFound,
.PATH_NOT_FOUND => return error.FileNotFound,
.ACCESS_DENIED => return error.PermissionDenied,
else => |err| return windows.unexpectedError(err),
}
}
/// Check user's permissions for a file, based on an open directory handle.
/// TODO currently this ignores `mode` and `flags` on Windows.
pub fn faccessat(dirfd: fd_t, path: []const u8, mode: u32, flags: u32) AccessError!void {
if (builtin.os.tag == .windows) {
const path_w = try windows.sliceToPrefixedFileW(path);
return faccessatW(dirfd, &path_w, mode, flags);
}
const path_c = try toPosixPath(path);
return faccessatZ(dirfd, &path_c, mode, flags);
}
/// Same as `faccessat` except the path parameter is null-terminated.
pub fn faccessatZ(dirfd: fd_t, path: [*:0]const u8, mode: u32, flags: u32) AccessError!void {
if (builtin.os.tag == .windows) {
const path_w = try windows.cStrToPrefixedFileW(path);
return faccessatW(dirfd, &path_w, mode, flags);
}
switch (errno(system.faccessat(dirfd, path, mode, flags))) {
0 => return,
EACCES => return error.PermissionDenied,
EROFS => return error.ReadOnlyFileSystem,
ELOOP => return error.SymLinkLoop,
ETXTBSY => return error.FileBusy,
ENOTDIR => return error.FileNotFound,
ENOENT => return error.FileNotFound,
ENAMETOOLONG => return error.NameTooLong,
EINVAL => unreachable,
EFAULT => unreachable,
EIO => return error.InputOutput,
ENOMEM => return error.SystemResources,
else => |err| return unexpectedErrno(err),
}
}
/// Same as `faccessat` except asserts the target is Windows and the path parameter
/// is NtDll-prefixed, null-terminated, WTF-16 encoded.
/// TODO currently this ignores `mode` and `flags`
pub fn faccessatW(dirfd: fd_t, sub_path_w: [*:0]const u16, mode: u32, flags: u32) AccessError!void {
if (sub_path_w[0] == '.' and sub_path_w[1] == 0) {
return;
}
if (sub_path_w[0] == '.' and sub_path_w[1] == '.' and sub_path_w[2] == 0) {
return;
}
const path_len_bytes = math.cast(u16, mem.lenZ(sub_path_w) * 2) catch |err| switch (err) {
error.Overflow => return error.NameTooLong,
};
var nt_name = windows.UNICODE_STRING{
.Length = path_len_bytes,
.MaximumLength = path_len_bytes,
.Buffer = @intToPtr([*]u16, @ptrToInt(sub_path_w)),
};
var attr = windows.OBJECT_ATTRIBUTES{
.Length = @sizeOf(windows.OBJECT_ATTRIBUTES),
.RootDirectory = if (std.fs.path.isAbsoluteWindowsW(sub_path_w)) null else dirfd,
.Attributes = 0, // Note we do not use OBJ_CASE_INSENSITIVE here.
.ObjectName = &nt_name,
.SecurityDescriptor = null,
.SecurityQualityOfService = null,
};
var basic_info: windows.FILE_BASIC_INFORMATION = undefined;
switch (windows.ntdll.NtQueryAttributesFile(&attr, &basic_info)) {
.SUCCESS => return,
.OBJECT_NAME_NOT_FOUND => return error.FileNotFound,
.OBJECT_PATH_NOT_FOUND => return error.FileNotFound,
.INVALID_PARAMETER => unreachable,
.ACCESS_DENIED => return error.PermissionDenied,
.OBJECT_PATH_SYNTAX_BAD => unreachable,
else => |rc| return windows.unexpectedStatus(rc),
}
}
pub const PipeError = error{
SystemFdQuotaExceeded,
ProcessFdQuotaExceeded,
} || UnexpectedError;
/// Creates a unidirectional data channel that can be used for interprocess communication.
pub fn pipe() PipeError![2]fd_t {
var fds: [2]fd_t = undefined;
switch (errno(system.pipe(&fds))) {
0 => return fds,
EINVAL => unreachable, // Invalid parameters to pipe()
EFAULT => unreachable, // Invalid fds pointer
ENFILE => return error.SystemFdQuotaExceeded,
EMFILE => return error.ProcessFdQuotaExceeded,
else => |err| return unexpectedErrno(err),
}
}
pub fn pipe2(flags: u32) PipeError![2]fd_t {
if (comptime std.Target.current.isDarwin()) {
var fds: [2]fd_t = try pipe();
if (flags == 0) return fds;
errdefer {
close(fds[0]);
close(fds[1]);
}
for (fds) |fd| switch (errno(system.fcntl(fd, F_SETFL, flags))) {
0 => {},
EINVAL => unreachable, // Invalid flags
EBADF => unreachable, // Always a race condition
else => |err| return unexpectedErrno(err),
};
return fds;
}
var fds: [2]fd_t = undefined;
switch (errno(system.pipe2(&fds, flags))) {
0 => return fds,
EINVAL => unreachable, // Invalid flags
EFAULT => unreachable, // Invalid fds pointer
ENFILE => return error.SystemFdQuotaExceeded,
EMFILE => return error.ProcessFdQuotaExceeded,
else => |err| return unexpectedErrno(err),
}
}
pub const SysCtlError = error{
PermissionDenied,
SystemResources,
NameTooLong,
UnknownName,
} || UnexpectedError;
pub fn sysctl(
name: []const c_int,
oldp: ?*c_void,
oldlenp: ?*usize,
newp: ?*c_void,
newlen: usize,
) SysCtlError!void {
const name_len = math.cast(c_uint, name.len) catch return error.NameTooLong;
switch (errno(system.sysctl(name.ptr, name_len, oldp, oldlenp, newp, newlen))) {
0 => return,
EFAULT => unreachable,
EPERM => return error.PermissionDenied,
ENOMEM => return error.SystemResources,
ENOENT => return error.UnknownName,
else => |err| return unexpectedErrno(err),
}
}
pub const sysctlbynameC = @compileError("deprecated: renamed to sysctlbynameZ");
pub fn sysctlbynameZ(
name: [*:0]const u8,
oldp: ?*c_void,
oldlenp: ?*usize,
newp: ?*c_void,
newlen: usize,
) SysCtlError!void {
switch (errno(system.sysctlbyname(name, oldp, oldlenp, newp, newlen))) {
0 => return,
EFAULT => unreachable,
EPERM => return error.PermissionDenied,
ENOMEM => return error.SystemResources,
ENOENT => return error.UnknownName,
else => |err| return unexpectedErrno(err),
}
}
pub fn gettimeofday(tv: ?*timeval, tz: ?*timezone) void {
switch (errno(system.gettimeofday(tv, tz))) {
0 => return,
EINVAL => unreachable,
else => unreachable,
}
}
pub const SeekError = error{Unseekable} || UnexpectedError;
/// Repositions read/write file offset relative to the beginning.
pub fn lseek_SET(fd: fd_t, offset: u64) SeekError!void {
if (builtin.os.tag == .linux and !builtin.link_libc and @sizeOf(usize) == 4) {
var result: u64 = undefined;
switch (errno(system.llseek(fd, offset, &result, SEEK_SET))) {
0 => return,
EBADF => unreachable, // always a race condition
EINVAL => return error.Unseekable,
EOVERFLOW => return error.Unseekable,
ESPIPE => return error.Unseekable,
ENXIO => return error.Unseekable,
else => |err| return unexpectedErrno(err),
}
}
if (builtin.os.tag == .windows) {
return windows.SetFilePointerEx_BEGIN(fd, offset);
}
const ipos = @bitCast(i64, offset); // the OS treats this as unsigned
switch (errno(system.lseek(fd, ipos, SEEK_SET))) {
0 => return,
EBADF => unreachable, // always a race condition
EINVAL => return error.Unseekable,
EOVERFLOW => return error.Unseekable,
ESPIPE => return error.Unseekable,
ENXIO => return error.Unseekable,
else => |err| return unexpectedErrno(err),
}
}
/// Repositions read/write file offset relative to the current offset.
pub fn lseek_CUR(fd: fd_t, offset: i64) SeekError!void {
if (builtin.os.tag == .linux and !builtin.link_libc and @sizeOf(usize) == 4) {
var result: u64 = undefined;
switch (errno(system.llseek(fd, @bitCast(u64, offset), &result, SEEK_CUR))) {
0 => return,
EBADF => unreachable, // always a race condition
EINVAL => return error.Unseekable,
EOVERFLOW => return error.Unseekable,
ESPIPE => return error.Unseekable,
ENXIO => return error.Unseekable,
else => |err| return unexpectedErrno(err),
}
}
if (builtin.os.tag == .windows) {
return windows.SetFilePointerEx_CURRENT(fd, offset);
}
switch (errno(system.lseek(fd, offset, SEEK_CUR))) {
0 => return,
EBADF => unreachable, // always a race condition
EINVAL => return error.Unseekable,
EOVERFLOW => return error.Unseekable,
ESPIPE => return error.Unseekable,
ENXIO => return error.Unseekable,
else => |err| return unexpectedErrno(err),
}
}
/// Repositions read/write file offset relative to the end.
pub fn lseek_END(fd: fd_t, offset: i64) SeekError!void {
if (builtin.os.tag == .linux and !builtin.link_libc and @sizeOf(usize) == 4) {
var result: u64 = undefined;
switch (errno(system.llseek(fd, @bitCast(u64, offset), &result, SEEK_END))) {
0 => return,
EBADF => unreachable, // always a race condition
EINVAL => return error.Unseekable,
EOVERFLOW => return error.Unseekable,
ESPIPE => return error.Unseekable,
ENXIO => return error.Unseekable,
else => |err| return unexpectedErrno(err),
}
}
if (builtin.os.tag == .windows) {
return windows.SetFilePointerEx_END(fd, offset);
}
switch (errno(system.lseek(fd, offset, SEEK_END))) {
0 => return,
EBADF => unreachable, // always a race condition
EINVAL => return error.Unseekable,
EOVERFLOW => return error.Unseekable,
ESPIPE => return error.Unseekable,
ENXIO => return error.Unseekable,
else => |err| return unexpectedErrno(err),
}
}
/// Returns the read/write file offset relative to the beginning.
pub fn lseek_CUR_get(fd: fd_t) SeekError!u64 {
if (builtin.os.tag == .linux and !builtin.link_libc and @sizeOf(usize) == 4) {
var result: u64 = undefined;
switch (errno(system.llseek(fd, 0, &result, SEEK_CUR))) {
0 => return result,
EBADF => unreachable, // always a race condition
EINVAL => return error.Unseekable,
EOVERFLOW => return error.Unseekable,
ESPIPE => return error.Unseekable,
ENXIO => return error.Unseekable,
else => |err| return unexpectedErrno(err),
}
}
if (builtin.os.tag == .windows) {
return windows.SetFilePointerEx_CURRENT_get(fd);
}
const rc = system.lseek(fd, 0, SEEK_CUR);
switch (errno(rc)) {
0 => return @bitCast(u64, rc),
EBADF => unreachable, // always a race condition
EINVAL => return error.Unseekable,
EOVERFLOW => return error.Unseekable,
ESPIPE => return error.Unseekable,
ENXIO => return error.Unseekable,
else => |err| return unexpectedErrno(err),
}
}
pub const FcntlError = error{
PermissionDenied,
FileBusy,
ProcessFdQuotaExceeded,
Locked,
} || UnexpectedError;
pub fn fcntl(fd: fd_t, cmd: i32, arg: usize) FcntlError!usize {
while (true) {
const rc = system.fcntl(fd, cmd, arg);
switch (errno(rc)) {
0 => return @intCast(usize, rc),
EINTR => continue,
EACCES => return error.Locked,
EBADF => unreachable,
EBUSY => return error.FileBusy,
EINVAL => unreachable, // invalid parameters
EPERM => return error.PermissionDenied,
EMFILE => return error.ProcessFdQuotaExceeded,
ENOTDIR => unreachable, // invalid parameter
else => |err| return unexpectedErrno(err),
}
}
}
pub const RealPathError = error{
FileNotFound,
AccessDenied,
NameTooLong,
NotSupported,
NotDir,
SymLinkLoop,
InputOutput,
FileTooBig,
IsDir,
ProcessFdQuotaExceeded,
SystemFdQuotaExceeded,
NoDevice,
SystemResources,
NoSpaceLeft,
FileSystem,
BadPathName,
DeviceBusy,
SharingViolation,
PipeBusy,
/// On Windows, file paths must be valid Unicode.
InvalidUtf8,
PathAlreadyExists,
} || UnexpectedError;
/// Return the canonicalized absolute pathname.
/// Expands all symbolic links and resolves references to `.`, `..`, and
/// extra `/` characters in `pathname`.
/// The return value is a slice of `out_buffer`, but not necessarily from the beginning.
/// See also `realpathC` and `realpathW`.
pub fn realpath(pathname: []const u8, out_buffer: *[MAX_PATH_BYTES]u8) RealPathError![]u8 {
if (builtin.os.tag == .windows) {
const pathname_w = try windows.sliceToPrefixedFileW(pathname);
return realpathW(&pathname_w, out_buffer);
}
const pathname_c = try toPosixPath(pathname);
return realpathZ(&pathname_c, out_buffer);
}
pub const realpathC = @compileError("deprecated: renamed realpathZ");
/// Same as `realpath` except `pathname` is null-terminated.
pub fn realpathZ(pathname: [*:0]const u8, out_buffer: *[MAX_PATH_BYTES]u8) RealPathError![]u8 {
if (builtin.os.tag == .windows) {
const pathname_w = try windows.cStrToPrefixedFileW(pathname);
return realpathW(&pathname_w, out_buffer);
}
if (builtin.os.tag == .linux and !builtin.link_libc) {
const fd = try openZ(pathname, linux.O_PATH | linux.O_NONBLOCK | linux.O_CLOEXEC, 0);
defer close(fd);
var procfs_buf: ["/proc/self/fd/-2147483648".len:0]u8 = undefined;
const proc_path = std.fmt.bufPrint(procfs_buf[0..], "/proc/self/fd/{}\x00", .{fd}) catch unreachable;
return readlinkZ(@ptrCast([*:0]const u8, proc_path.ptr), out_buffer);
}
const result_path = std.c.realpath(pathname, out_buffer) orelse switch (std.c._errno().*) {
EINVAL => unreachable,
EBADF => unreachable,
EFAULT => unreachable,
EACCES => return error.AccessDenied,
ENOENT => return error.FileNotFound,
ENOTSUP => return error.NotSupported,
ENOTDIR => return error.NotDir,
ENAMETOOLONG => return error.NameTooLong,
ELOOP => return error.SymLinkLoop,
EIO => return error.InputOutput,
else => |err| return unexpectedErrno(@intCast(usize, err)),
};
return mem.spanZ(result_path);
}
/// Same as `realpath` except `pathname` is null-terminated and UTF16LE-encoded.
/// TODO use ntdll for better semantics
pub fn realpathW(pathname: [*:0]const u16, out_buffer: *[MAX_PATH_BYTES]u8) RealPathError![]u8 {
const h_file = try windows.CreateFileW(
pathname,
windows.GENERIC_READ,
windows.FILE_SHARE_READ,
null,
windows.OPEN_EXISTING,
windows.FILE_FLAG_BACKUP_SEMANTICS,
null,
);
defer windows.CloseHandle(h_file);
var wide_buf: [windows.PATH_MAX_WIDE]u16 = undefined;
const wide_slice = try windows.GetFinalPathNameByHandleW(h_file, &wide_buf, wide_buf.len, windows.VOLUME_NAME_DOS);
// Windows returns \\?\ prepended to the path.
// We strip it to make this function consistent across platforms.
const prefix = [_]u16{ '\\', '\\', '?', '\\' };
const start_index = if (mem.startsWith(u16, wide_slice, &prefix)) prefix.len else 0;
// Trust that Windows gives us valid UTF-16LE.
const end_index = std.unicode.utf16leToUtf8(out_buffer, wide_slice[start_index..]) catch unreachable;
return out_buffer[0..end_index];
}
/// Spurious wakeups are possible and no precision of timing is guaranteed.
pub fn nanosleep(seconds: u64, nanoseconds: u64) void {
var req = timespec{
.tv_sec = math.cast(isize, seconds) catch math.maxInt(isize),
.tv_nsec = math.cast(isize, nanoseconds) catch math.maxInt(isize),
};
var rem: timespec = undefined;
while (true) {
switch (errno(system.nanosleep(&req, &rem))) {
EFAULT => unreachable,
EINVAL => {
// Sometimes Darwin returns EINVAL for no reason.
// We treat it as a spurious wakeup.
return;
},
EINTR => {
req = rem;
continue;
},
// This prong handles success as well as unexpected errors.
else => return,
}
}
}
pub fn dl_iterate_phdr(
context: var,
comptime Error: type,
comptime callback: fn (info: *dl_phdr_info, size: usize, context: @TypeOf(context)) Error!void,
) Error!void {
const Context = @TypeOf(context);
if (builtin.object_format != .elf)
@compileError("dl_iterate_phdr is not available for this target");
if (builtin.link_libc) {
switch (system.dl_iterate_phdr(struct {
fn callbackC(info: *dl_phdr_info, size: usize, data: ?*c_void) callconv(.C) c_int {
const context_ptr = @ptrCast(*const Context, @alignCast(@alignOf(*const Context), data));
callback(info, size, context_ptr.*) catch |err| return @errorToInt(err);
return 0;
}
}.callbackC, @intToPtr(?*c_void, @ptrToInt(&context)))) {
0 => return,
else => |err| return @errSetCast(Error, @intToError(@intCast(u16, err))), // TODO don't hardcode u16
}
}
const elf_base = std.process.getBaseAddress();
const ehdr = @intToPtr(*elf.Ehdr, elf_base);
// Make sure the base address points to an ELF image
assert(mem.eql(u8, ehdr.e_ident[0..4], "\x7fELF"));
const n_phdr = ehdr.e_phnum;
const phdrs = (@intToPtr([*]elf.Phdr, elf_base + ehdr.e_phoff))[0..n_phdr];
var it = dl.linkmap_iterator(phdrs) catch unreachable;
// The executable has no dynamic link segment, create a single entry for