zig/lib/std/process.zig
Andrew Kelley 60cd11bd4b
get rid of std.os.foo.is_the_target
It had the downside of running all the comptime blocks and resolving
all the usingnamespaces of each system, when just trying to discover if
the current system is a particular one.

For Darwin, where it's nice to use `std.Target.current.isDarwin()`, this
demonstrates the utility that #425 would provide.
2019-10-24 01:14:52 -04:00

617 lines
21 KiB
Zig

const builtin = @import("builtin");
const std = @import("std.zig");
const os = std.os;
const fs = std.fs;
const BufMap = std.BufMap;
const Buffer = std.Buffer;
const mem = std.mem;
const math = std.math;
const Allocator = mem.Allocator;
const assert = std.debug.assert;
const testing = std.testing;
pub const abort = os.abort;
pub const exit = os.exit;
pub const changeCurDir = os.chdir;
pub const changeCurDirC = os.chdirC;
/// The result is a slice of `out_buffer`, from index `0`.
pub fn getCwd(out_buffer: *[fs.MAX_PATH_BYTES]u8) ![]u8 {
return os.getcwd(out_buffer);
}
/// Caller must free the returned memory.
pub fn getCwdAlloc(allocator: *Allocator) ![]u8 {
var buf: [fs.MAX_PATH_BYTES]u8 = undefined;
return mem.dupe(allocator, u8, try os.getcwd(&buf));
}
test "getCwdAlloc" {
// at least call it so it gets compiled
var buf: [1000]u8 = undefined;
const allocator = &std.heap.FixedBufferAllocator.init(&buf).allocator;
_ = getCwdAlloc(allocator) catch undefined;
}
/// Caller must free result when done.
/// TODO make this go through libc when we have it
pub fn getEnvMap(allocator: *Allocator) !BufMap {
var result = BufMap.init(allocator);
errdefer result.deinit();
if (builtin.os == .windows) {
const ptr = try os.windows.GetEnvironmentStringsW();
defer os.windows.FreeEnvironmentStringsW(ptr);
var i: usize = 0;
while (true) {
if (ptr[i] == 0) return result;
const key_start = i;
while (ptr[i] != 0 and ptr[i] != '=') : (i += 1) {}
const key_w = ptr[key_start..i];
const key = try std.unicode.utf16leToUtf8Alloc(allocator, key_w);
errdefer allocator.free(key);
if (ptr[i] == '=') i += 1;
const value_start = i;
while (ptr[i] != 0) : (i += 1) {}
const value_w = ptr[value_start..i];
const value = try std.unicode.utf16leToUtf8Alloc(allocator, value_w);
errdefer allocator.free(value);
i += 1; // skip over null byte
try result.setMove(key, value);
}
} else if (builtin.os == .wasi) {
var environ_count: usize = undefined;
var environ_buf_size: usize = undefined;
const environ_sizes_get_ret = os.wasi.environ_sizes_get(&environ_count, &environ_buf_size);
if (environ_sizes_get_ret != os.wasi.ESUCCESS) {
return os.unexpectedErrno(environ_sizes_get_ret);
}
// TODO: Verify that the documentation is incorrect
// https://github.com/WebAssembly/WASI/issues/27
var environ = try allocator.alloc(?[*]u8, environ_count + 1);
defer allocator.free(environ);
var environ_buf = try std.heap.wasm_allocator.alloc(u8, environ_buf_size);
defer allocator.free(environ_buf);
const environ_get_ret = os.wasi.environ_get(environ.ptr, environ_buf.ptr);
if (environ_get_ret != os.wasi.ESUCCESS) {
return os.unexpectedErrno(environ_get_ret);
}
for (environ) |env| {
if (env) |ptr| {
const pair = mem.toSlice(u8, ptr);
var parts = mem.separate(pair, "=");
const key = parts.next().?;
const value = parts.next().?;
try result.set(key, value);
}
}
return result;
} else {
for (os.environ) |ptr| {
var line_i: usize = 0;
while (ptr[line_i] != 0 and ptr[line_i] != '=') : (line_i += 1) {}
const key = ptr[0..line_i];
var end_i: usize = line_i;
while (ptr[end_i] != 0) : (end_i += 1) {}
const value = ptr[line_i + 1 .. end_i];
try result.set(key, value);
}
return result;
}
}
test "os.getEnvMap" {
var env = try getEnvMap(std.debug.global_allocator);
defer env.deinit();
}
pub const GetEnvVarOwnedError = error{
OutOfMemory,
EnvironmentVariableNotFound,
/// See https://github.com/ziglang/zig/issues/1774
InvalidUtf8,
};
/// Caller must free returned memory.
/// TODO make this go through libc when we have it
pub fn getEnvVarOwned(allocator: *mem.Allocator, key: []const u8) GetEnvVarOwnedError![]u8 {
if (builtin.os == .windows) {
const key_with_null = try std.unicode.utf8ToUtf16LeWithNull(allocator, key);
defer allocator.free(key_with_null);
var buf = try allocator.alloc(u16, 256);
defer allocator.free(buf);
while (true) {
const windows_buf_len = math.cast(os.windows.DWORD, buf.len) catch return error.OutOfMemory;
const result = os.windows.GetEnvironmentVariableW(
key_with_null.ptr,
buf.ptr,
windows_buf_len,
) catch |err| switch (err) {
error.Unexpected => return error.EnvironmentVariableNotFound,
else => |e| return e,
};
if (result > buf.len) {
buf = try allocator.realloc(buf, result);
continue;
}
return std.unicode.utf16leToUtf8Alloc(allocator, buf[0..result]) catch |err| switch (err) {
error.DanglingSurrogateHalf => return error.InvalidUtf8,
error.ExpectedSecondSurrogateHalf => return error.InvalidUtf8,
error.UnexpectedSecondSurrogateHalf => return error.InvalidUtf8,
else => |e| return e,
};
}
} else {
const result = os.getenv(key) orelse return error.EnvironmentVariableNotFound;
return mem.dupe(allocator, u8, result);
}
}
test "os.getEnvVarOwned" {
var ga = std.debug.global_allocator;
testing.expectError(error.EnvironmentVariableNotFound, getEnvVarOwned(ga, "BADENV"));
}
pub const ArgIteratorPosix = struct {
index: usize,
count: usize,
pub fn init() ArgIteratorPosix {
return ArgIteratorPosix{
.index = 0,
.count = os.argv.len,
};
}
pub fn next(self: *ArgIteratorPosix) ?[]const u8 {
if (self.index == self.count) return null;
const s = os.argv[self.index];
self.index += 1;
return mem.toSlice(u8, s);
}
pub fn skip(self: *ArgIteratorPosix) bool {
if (self.index == self.count) return false;
self.index += 1;
return true;
}
};
pub const ArgIteratorWindows = struct {
index: usize,
cmd_line: [*]const u8,
in_quote: bool,
quote_count: usize,
seen_quote_count: usize,
pub const NextError = error{OutOfMemory};
pub fn init() ArgIteratorWindows {
return initWithCmdLine(os.windows.kernel32.GetCommandLineA());
}
pub fn initWithCmdLine(cmd_line: [*]const u8) ArgIteratorWindows {
return ArgIteratorWindows{
.index = 0,
.cmd_line = cmd_line,
.in_quote = false,
.quote_count = countQuotes(cmd_line),
.seen_quote_count = 0,
};
}
/// You must free the returned memory when done.
pub fn next(self: *ArgIteratorWindows, allocator: *Allocator) ?(NextError![]u8) {
// march forward over whitespace
while (true) : (self.index += 1) {
const byte = self.cmd_line[self.index];
switch (byte) {
0 => return null,
' ', '\t' => continue,
else => break,
}
}
return self.internalNext(allocator);
}
pub fn skip(self: *ArgIteratorWindows) bool {
// march forward over whitespace
while (true) : (self.index += 1) {
const byte = self.cmd_line[self.index];
switch (byte) {
0 => return false,
' ', '\t' => continue,
else => break,
}
}
var backslash_count: usize = 0;
while (true) : (self.index += 1) {
const byte = self.cmd_line[self.index];
switch (byte) {
0 => return true,
'"' => {
const quote_is_real = backslash_count % 2 == 0;
if (quote_is_real) {
self.seen_quote_count += 1;
}
},
'\\' => {
backslash_count += 1;
},
' ', '\t' => {
if (self.seen_quote_count % 2 == 0 or self.seen_quote_count == self.quote_count) {
return true;
}
backslash_count = 0;
},
else => {
backslash_count = 0;
continue;
},
}
}
}
fn internalNext(self: *ArgIteratorWindows, allocator: *Allocator) NextError![]u8 {
var buf = try Buffer.initSize(allocator, 0);
defer buf.deinit();
var backslash_count: usize = 0;
while (true) : (self.index += 1) {
const byte = self.cmd_line[self.index];
switch (byte) {
0 => return buf.toOwnedSlice(),
'"' => {
const quote_is_real = backslash_count % 2 == 0;
try self.emitBackslashes(&buf, backslash_count / 2);
backslash_count = 0;
if (quote_is_real) {
self.seen_quote_count += 1;
if (self.seen_quote_count == self.quote_count and self.seen_quote_count % 2 == 1) {
try buf.appendByte('"');
}
} else {
try buf.appendByte('"');
}
},
'\\' => {
backslash_count += 1;
},
' ', '\t' => {
try self.emitBackslashes(&buf, backslash_count);
backslash_count = 0;
if (self.seen_quote_count % 2 == 1 and self.seen_quote_count != self.quote_count) {
try buf.appendByte(byte);
} else {
return buf.toOwnedSlice();
}
},
else => {
try self.emitBackslashes(&buf, backslash_count);
backslash_count = 0;
try buf.appendByte(byte);
},
}
}
}
fn emitBackslashes(self: *ArgIteratorWindows, buf: *Buffer, emit_count: usize) !void {
var i: usize = 0;
while (i < emit_count) : (i += 1) {
try buf.appendByte('\\');
}
}
fn countQuotes(cmd_line: [*]const u8) usize {
var result: usize = 0;
var backslash_count: usize = 0;
var index: usize = 0;
while (true) : (index += 1) {
const byte = cmd_line[index];
switch (byte) {
0 => return result,
'\\' => backslash_count += 1,
'"' => {
result += 1 - (backslash_count % 2);
backslash_count = 0;
},
else => {
backslash_count = 0;
},
}
}
}
};
pub const ArgIterator = struct {
const InnerType = if (builtin.os == .windows) ArgIteratorWindows else ArgIteratorPosix;
inner: InnerType,
pub fn init() ArgIterator {
if (builtin.os == .wasi) {
// TODO: Figure out a compatible interface accomodating WASI
@compileError("ArgIterator is not yet supported in WASI. Use argsAlloc and argsFree instead.");
}
return ArgIterator{ .inner = InnerType.init() };
}
pub const NextError = ArgIteratorWindows.NextError;
/// You must free the returned memory when done.
pub fn next(self: *ArgIterator, allocator: *Allocator) ?(NextError![]u8) {
if (builtin.os == .windows) {
return self.inner.next(allocator);
} else {
return mem.dupe(allocator, u8, self.inner.next() orelse return null);
}
}
/// If you only are targeting posix you can call this and not need an allocator.
pub fn nextPosix(self: *ArgIterator) ?[]const u8 {
return self.inner.next();
}
/// Parse past 1 argument without capturing it.
/// Returns `true` if skipped an arg, `false` if we are at the end.
pub fn skip(self: *ArgIterator) bool {
return self.inner.skip();
}
};
pub fn args() ArgIterator {
return ArgIterator.init();
}
/// Caller must call argsFree on result.
pub fn argsAlloc(allocator: *mem.Allocator) ![][]u8 {
if (builtin.os == .wasi) {
var count: usize = undefined;
var buf_size: usize = undefined;
const args_sizes_get_ret = os.wasi.args_sizes_get(&count, &buf_size);
if (args_sizes_get_ret != os.wasi.ESUCCESS) {
return os.unexpectedErrno(args_sizes_get_ret);
}
var argv = try allocator.alloc([*]u8, count);
defer allocator.free(argv);
var argv_buf = try allocator.alloc(u8, buf_size);
const args_get_ret = os.wasi.args_get(argv.ptr, argv_buf.ptr);
if (args_get_ret != os.wasi.ESUCCESS) {
return os.unexpectedErrno(args_get_ret);
}
var result_slice = try allocator.alloc([]u8, count);
var i: usize = 0;
while (i < count) : (i += 1) {
result_slice[i] = mem.toSlice(u8, argv[i]);
}
return result_slice;
}
// TODO refactor to only make 1 allocation.
var it = args();
var contents = try Buffer.initSize(allocator, 0);
defer contents.deinit();
var slice_list = std.ArrayList(usize).init(allocator);
defer slice_list.deinit();
while (it.next(allocator)) |arg_or_err| {
const arg = try arg_or_err;
defer allocator.free(arg);
try contents.append(arg);
try slice_list.append(arg.len);
}
const contents_slice = contents.toSliceConst();
const slice_sizes = slice_list.toSliceConst();
const slice_list_bytes = try math.mul(usize, @sizeOf([]u8), slice_sizes.len);
const total_bytes = try math.add(usize, slice_list_bytes, contents_slice.len);
const buf = try allocator.alignedAlloc(u8, @alignOf([]u8), total_bytes);
errdefer allocator.free(buf);
const result_slice_list = @bytesToSlice([]u8, buf[0..slice_list_bytes]);
const result_contents = buf[slice_list_bytes..];
mem.copy(u8, result_contents, contents_slice);
var contents_index: usize = 0;
for (slice_sizes) |len, i| {
const new_index = contents_index + len;
result_slice_list[i] = result_contents[contents_index..new_index];
contents_index = new_index;
}
return result_slice_list;
}
pub fn argsFree(allocator: *mem.Allocator, args_alloc: []const []u8) void {
if (builtin.os == .wasi) {
const last_item = args_alloc[args_alloc.len - 1];
const last_byte_addr = @ptrToInt(last_item.ptr) + last_item.len + 1; // null terminated
const first_item_ptr = args_alloc[0].ptr;
const len = last_byte_addr - @ptrToInt(first_item_ptr);
allocator.free(first_item_ptr[0..len]);
return allocator.free(args_alloc);
}
var total_bytes: usize = 0;
for (args_alloc) |arg| {
total_bytes += @sizeOf([]u8) + arg.len;
}
const unaligned_allocated_buf = @ptrCast([*]const u8, args_alloc.ptr)[0..total_bytes];
const aligned_allocated_buf = @alignCast(@alignOf([]u8), unaligned_allocated_buf);
return allocator.free(aligned_allocated_buf);
}
test "windows arg parsing" {
testWindowsCmdLine(c"a b\tc d", [_][]const u8{ "a", "b", "c", "d" });
testWindowsCmdLine(c"\"abc\" d e", [_][]const u8{ "abc", "d", "e" });
testWindowsCmdLine(c"a\\\\\\b d\"e f\"g h", [_][]const u8{ "a\\\\\\b", "de fg", "h" });
testWindowsCmdLine(c"a\\\\\\\"b c d", [_][]const u8{ "a\\\"b", "c", "d" });
testWindowsCmdLine(c"a\\\\\\\\\"b c\" d e", [_][]const u8{ "a\\\\b c", "d", "e" });
testWindowsCmdLine(c"a b\tc \"d f", [_][]const u8{ "a", "b", "c", "\"d", "f" });
testWindowsCmdLine(c"\".\\..\\zig-cache\\build\" \"bin\\zig.exe\" \".\\..\" \".\\..\\zig-cache\" \"--help\"", [_][]const u8{
".\\..\\zig-cache\\build",
"bin\\zig.exe",
".\\..",
".\\..\\zig-cache",
"--help",
});
}
fn testWindowsCmdLine(input_cmd_line: [*]const u8, expected_args: []const []const u8) void {
var it = ArgIteratorWindows.initWithCmdLine(input_cmd_line);
for (expected_args) |expected_arg| {
const arg = it.next(std.debug.global_allocator).? catch unreachable;
testing.expectEqualSlices(u8, expected_arg, arg);
}
testing.expect(it.next(std.debug.global_allocator) == null);
}
pub const UserInfo = struct {
uid: u32,
gid: u32,
};
/// POSIX function which gets a uid from username.
pub fn getUserInfo(name: []const u8) !UserInfo {
return switch (builtin.os) {
.linux, .macosx, .watchos, .tvos, .ios, .freebsd, .netbsd => posixGetUserInfo(name),
else => @compileError("Unsupported OS"),
};
}
/// TODO this reads /etc/passwd. But sometimes the user/id mapping is in something else
/// like NIS, AD, etc. See `man nss` or look at an strace for `id myuser`.
pub fn posixGetUserInfo(name: []const u8) !UserInfo {
var in_stream = try io.InStream.open("/etc/passwd", null);
defer in_stream.close();
const State = enum {
Start,
WaitForNextLine,
SkipPassword,
ReadUserId,
ReadGroupId,
};
var buf: [std.mem.page_size]u8 = undefined;
var name_index: usize = 0;
var state = State.Start;
var uid: u32 = 0;
var gid: u32 = 0;
while (true) {
const amt_read = try in_stream.read(buf[0..]);
for (buf[0..amt_read]) |byte| {
switch (state) {
.Start => switch (byte) {
':' => {
state = if (name_index == name.len) State.SkipPassword else State.WaitForNextLine;
},
'\n' => return error.CorruptPasswordFile,
else => {
if (name_index == name.len or name[name_index] != byte) {
state = .WaitForNextLine;
}
name_index += 1;
},
},
.WaitForNextLine => switch (byte) {
'\n' => {
name_index = 0;
state = .Start;
},
else => continue,
},
.SkipPassword => switch (byte) {
'\n' => return error.CorruptPasswordFile,
':' => {
state = .ReadUserId;
},
else => continue,
},
.ReadUserId => switch (byte) {
':' => {
state = .ReadGroupId;
},
'\n' => return error.CorruptPasswordFile,
else => {
const digit = switch (byte) {
'0'...'9' => byte - '0',
else => return error.CorruptPasswordFile,
};
if (@mulWithOverflow(u32, uid, 10, *uid)) return error.CorruptPasswordFile;
if (@addWithOverflow(u32, uid, digit, *uid)) return error.CorruptPasswordFile;
},
},
.ReadGroupId => switch (byte) {
'\n', ':' => {
return UserInfo{
.uid = uid,
.gid = gid,
};
},
else => {
const digit = switch (byte) {
'0'...'9' => byte - '0',
else => return error.CorruptPasswordFile,
};
if (@mulWithOverflow(u32, gid, 10, *gid)) return error.CorruptPasswordFile;
if (@addWithOverflow(u32, gid, digit, *gid)) return error.CorruptPasswordFile;
},
},
}
}
if (amt_read < buf.len) return error.UserNotFound;
}
}
pub fn getBaseAddress() usize {
switch (builtin.os) {
.linux => {
const base = os.system.getauxval(std.elf.AT_BASE);
if (base != 0) {
return base;
}
const phdr = os.system.getauxval(std.elf.AT_PHDR);
return phdr - @sizeOf(std.elf.Ehdr);
},
.macosx, .freebsd, .netbsd => {
return @ptrToInt(&std.c._mh_execute_header);
},
.windows => return @ptrToInt(os.windows.kernel32.GetModuleHandleW(null)),
else => @compileError("Unsupported OS"),
}
}