diff --git a/lib/std/os.zig b/lib/std/os.zig index 16ab314c14..59cde5d606 100644 --- a/lib/std/os.zig +++ b/lib/std/os.zig @@ -1588,7 +1588,7 @@ pub const symlinkatC = @compileError("deprecated: renamed to symlinkatZ"); /// WASI-only. The same as `symlinkat` but targeting WASI. /// See also `symlinkat`. pub fn symlinkatWasi(target_path: []const u8, newdirfd: fd_t, sym_link_path: []const u8) SymLinkError!void { - switch (wasi.path_symlink(sym_link_path.ptr, sym_link_path.len, newdirfd, target_path.ptr, target_path.len)) { + switch (wasi.path_symlink(target_path.ptr, target_path.len, newdirfd, sym_link_path.ptr, sym_link_path.len)) { wasi.ESUCCESS => {}, wasi.EFAULT => unreachable, wasi.EINVAL => unreachable, @@ -2343,12 +2343,54 @@ pub fn readlinkZ(file_path: [*:0]const u8, out_buffer: []u8) ReadLinkError![]u8 } } +/// Similar to `readlink` except reads value of a symbolink link **relative** to `dirfd` directory handle. +/// The return value is a slice of `out_buffer` from index 0. +/// See also `readlinkatWasi`, `realinkatZ` and `realinkatW`. +pub fn readlinkat(dirfd: fd_t, file_path: []const u8, out_buffer: []u8) ReadLinkError![]u8 { + if (builtin.os.tag == .wasi) { + return readlinkatWasi(dirfd, file_path, out_buffer); + } + if (builtin.os.tag == .windows) { + const file_path_w = try windows.cStrToPrefixedFileW(file_path); + return readlinkatW(dirfd, file_path.span().ptr, out_buffer); + } + const file_path_c = try toPosixPath(file_path); + return readlinkatZ(dirfd, &file_path_c, out_buffer); +} + pub const readlinkatC = @compileError("deprecated: renamed to readlinkatZ"); +/// WASI-only. Same as `readlinkat` but targets WASI. +/// See also `readlinkat`. +pub fn readlinkatWasi(dirfd: fd_t, file_path: []const u8, out_buffer: []u8) ReadLinkError![]u8 { + var bufused: usize = undefined; + switch (wasi.path_readlink(dirfd, file_path.ptr, file_path.len, out_buffer.ptr, out_buffer.len, &bufused)) { + wasi.ESUCCESS => return out_buffer[0..bufused], + wasi.EACCES => return error.AccessDenied, + wasi.EFAULT => unreachable, + wasi.EINVAL => unreachable, + wasi.EIO => return error.FileSystem, + wasi.ELOOP => return error.SymLinkLoop, + wasi.ENAMETOOLONG => return error.NameTooLong, + wasi.ENOENT => return error.FileNotFound, + wasi.ENOMEM => return error.SystemResources, + wasi.ENOTDIR => return error.NotDir, + else => |err| return unexpectedErrno(err), + } +} + +/// Windows-only. Same as `readlinkat` except `file_path` is null-terminated, WTF16 encoded. +/// See also `readlinkat`. +pub fn readlinkatW(dirfd: fd_t, file_path: [*:0]const u16, out_buffer: []u8) ReadLinkError![]u8 { + @compileError("TODO implement on Windows"); +} + +/// Same as `readlinkat` except `file_path` is null-terminated. +/// See also `readlinkat`. 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"); + return readlinkatW(dirfd, file_path_w.span().ptr, out_buffer); } const rc = system.readlinkat(dirfd, file_path, out_buffer.ptr, out_buffer.len); switch (errno(rc)) { diff --git a/lib/std/os/test.zig b/lib/std/os/test.zig index d4624929ee..c298a0a203 100644 --- a/lib/std/os/test.zig +++ b/lib/std/os/test.zig @@ -19,6 +19,9 @@ const tmpDir = std.testing.tmpDir; const Dir = std.fs.Dir; test "readlinkat" { + // enable when `readlinkat` and `symlinkat` are implemented on Windows + if (builtin.os.tag == .windows) return error.SkipZigTest; + var tmp = tmpDir(.{}); defer tmp.cleanup(); @@ -28,7 +31,10 @@ test "readlinkat" { // create a symbolic link try os.symlinkat("file.txt", tmp.dir.fd, "link"); - // TODO read the link + // read the link + var buffer: [fs.MAX_PATH_BYTES]u8 = undefined; + const read_link = try os.readlinkat(tmp.dir.fd, "link", buffer[0..]); + expect(mem.eql(u8, "file.txt", read_link)); } test "makePath, put some files in it, deleteTree" {