Adds most of the toolsHEADmaster

1 files changed, 979 insertions, 0 deletions

diff --git a/v_windows/v/old/vlib/os/os_c.v b/v_windows/v/old/vlib/os/os_c.v
new file mode 100644
index 0000000..8275a9f
--- /dev/null
+++ b/v_windows/v/old/vlib/os/os_c.v
@@ -0,0 +1,979 @@
+module os
+
+#include <sys/stat.h> // #include <signal.h>
+#include <errno.h>
+
+struct C.dirent {
+	d_name [256]char
+}
+
+fn C.readdir(voidptr) &C.dirent
+
+fn C.readlink(pathname &char, buf &char, bufsiz size_t) int
+
+fn C.getline(voidptr, voidptr, voidptr) int
+
+fn C.ftell(fp voidptr) i64
+
+fn C.sigaction(int, voidptr, int) int
+
+fn C.open(&char, int, ...int) int
+
+fn C.fdopen(fd int, mode &char) &C.FILE
+
+fn C.ferror(stream &C.FILE) int
+
+fn C.feof(stream &C.FILE) int
+
+fn C.CopyFile(&u16, &u16, bool) int
+
+// fn C.lstat(charptr, voidptr) u64
+
+fn C._wstat64(&u16, voidptr) u64
+
+fn C.chown(&char, int, int) int
+
+fn C.ftruncate(voidptr, u64) int
+
+fn C._chsize_s(voidptr, u64) int
+
+// fn C.proc_pidpath(int, byteptr, int) int
+struct C.stat {
+	st_size  u64
+	st_mode  u32
+	st_mtime int
+}
+
+struct C.__stat64 {
+	st_size  u64
+	st_mode  u32
+	st_mtime int
+}
+
+struct C.DIR {
+}
+
+type FN_SA_Handler = fn (sig int)
+
+struct C.sigaction {
+mut:
+	sa_mask      int
+	sa_sigaction int
+	sa_flags     int
+	sa_handler   FN_SA_Handler
+}
+
+struct C.dirent {
+	d_name &byte
+}
+
+// read_bytes returns all bytes read from file in `path`.
+[manualfree]
+pub fn read_bytes(path string) ?[]byte {
+	mut fp := vfopen(path, 'rb') ?
+	defer {
+		C.fclose(fp)
+	}
+	cseek := C.fseek(fp, 0, C.SEEK_END)
+	if cseek != 0 {
+		return error('fseek failed')
+	}
+	fsize := C.ftell(fp)
+	if fsize < 0 {
+		return error('ftell failed')
+	}
+	C.rewind(fp)
+	mut res := []byte{len: int(fsize)}
+	nr_read_elements := int(C.fread(res.data, fsize, 1, fp))
+	if nr_read_elements == 0 && fsize > 0 {
+		return error('fread failed')
+	}
+	res.trim(nr_read_elements * int(fsize))
+	return res
+}
+
+// read_file reads the file in `path` and returns the contents.
+pub fn read_file(path string) ?string {
+	mode := 'rb'
+	mut fp := vfopen(path, mode) ?
+	defer {
+		C.fclose(fp)
+	}
+	cseek := C.fseek(fp, 0, C.SEEK_END)
+	if cseek != 0 {
+		return error('fseek failed')
+	}
+	fsize := C.ftell(fp)
+	if fsize < 0 {
+		return error('ftell failed')
+	}
+	// C.fseek(fp, 0, SEEK_SET)  // same as `C.rewind(fp)` below
+	C.rewind(fp)
+	unsafe {
+		mut str := malloc_noscan(int(fsize) + 1)
+		nelements := int(C.fread(str, 1, fsize, fp))
+		is_eof := int(C.feof(fp))
+		is_error := int(C.ferror(fp))
+		if is_eof == 0 && is_error != 0 {
+			free(str)
+			return error('fread failed')
+		}
+		str[nelements] = 0
+		if nelements == 0 {
+			// It is highly likely that the file was a virtual file from
+			// /sys or /proc, with information generated on the fly, so
+			// fsize was not reliably reported. Using vstring() here is
+			// slower (it calls strlen internally), but will return more
+			// consistent results.
+			// For example reading from /sys/class/sound/card0/id produces
+			// a `PCH\n` string, but fsize is 4096, and otherwise you would
+			// get a V string with .len = 4096 and .str = "PCH\n\\000".
+			return str.vstring()
+		}
+		return str.vstring_with_len(nelements)
+	}
+}
+
+// ***************************** OS ops ************************
+//
+// truncate changes the size of the file located in `path` to `len`.
+// Note that changing symbolic links on Windows only works as admin.
+pub fn truncate(path string, len u64) ? {
+	fp := C.open(&char(path.str), o_wronly | o_trunc)
+	defer {
+		C.close(fp)
+	}
+	if fp < 0 {
+		return error_with_code(posix_get_error_msg(C.errno), C.errno)
+	}
+	$if windows {
+		if C._chsize_s(fp, len) != 0 {
+			return error_with_code(posix_get_error_msg(C.errno), C.errno)
+		}
+	} $else {
+		if C.ftruncate(fp, len) != 0 {
+			return error_with_code(posix_get_error_msg(C.errno), C.errno)
+		}
+	}
+}
+
+fn eprintln_unknown_file_size() {
+	eprintln('os.file_size() Cannot determine file-size: ' + posix_get_error_msg(C.errno))
+}
+
+// file_size returns the size of the file located in `path`.
+// If an error occurs it returns 0.
+// Note that use of this on symbolic links on Windows returns always 0.
+pub fn file_size(path string) u64 {
+	mut s := C.stat{}
+	unsafe {
+		$if x64 {
+			$if windows {
+				mut swin := C.__stat64{}
+				if C._wstat64(path.to_wide(), voidptr(&swin)) != 0 {
+					eprintln_unknown_file_size()
+					return 0
+				}
+				return swin.st_size
+			} $else {
+				if C.stat(&char(path.str), &s) != 0 {
+					eprintln_unknown_file_size()
+					return 0
+				}
+				return u64(s.st_size)
+			}
+		}
+		$if x32 {
+			$if debug {
+				eprintln('Using os.file_size() on 32bit systems may not work on big files.')
+			}
+			$if windows {
+				if C._wstat(path.to_wide(), voidptr(&s)) != 0 {
+					eprintln_unknown_file_size()
+					return 0
+				}
+				return u64(s.st_size)
+			} $else {
+				if C.stat(&char(path.str), &s) != 0 {
+					eprintln_unknown_file_size()
+					return 0
+				}
+				return u64(s.st_size)
+			}
+		}
+	}
+	return 0
+}
+
+// mv moves files or folders from `src` to `dst`.
+pub fn mv(src string, dst string) ? {
+	mut rdst := dst
+	if is_dir(rdst) {
+		rdst = join_path(rdst.trim_right(path_separator), file_name(src.trim_right(path_separator)))
+	}
+	$if windows {
+		w_src := src.replace('/', '\\')
+		w_dst := rdst.replace('/', '\\')
+		ret := C._wrename(w_src.to_wide(), w_dst.to_wide())
+		if ret != 0 {
+			return error_with_code('failed to rename $src to $dst', int(ret))
+		}
+	} $else {
+		ret := C.rename(&char(src.str), &char(rdst.str))
+		if ret != 0 {
+			return error_with_code('failed to rename $src to $dst', int(ret))
+		}
+	}
+}
+
+// cp copies files or folders from `src` to `dst`.
+pub fn cp(src string, dst string) ? {
+	$if windows {
+		w_src := src.replace('/', '\\')
+		w_dst := dst.replace('/', '\\')
+		if C.CopyFile(w_src.to_wide(), w_dst.to_wide(), false) == 0 {
+			result := C.GetLastError()
+			return error_with_code('failed to copy $src to $dst', int(result))
+		}
+	} $else {
+		fp_from := C.open(&char(src.str), C.O_RDONLY)
+		if fp_from < 0 { // Check if file opened
+			return error_with_code('cp: failed to open $src', int(fp_from))
+		}
+		fp_to := C.open(&char(dst.str), C.O_WRONLY | C.O_CREAT | C.O_TRUNC, C.S_IWUSR | C.S_IRUSR)
+		if fp_to < 0 { // Check if file opened (permissions problems ...)
+			C.close(fp_from)
+			return error_with_code('cp (permission): failed to write to $dst (fp_to: $fp_to)',
+				int(fp_to))
+		}
+		// TODO use defer{} to close files in case of error or return.
+		// Currently there is a C-Error when building.
+		mut buf := [1024]byte{}
+		mut count := 0
+		for {
+			count = C.read(fp_from, &buf[0], sizeof(buf))
+			if count == 0 {
+				break
+			}
+			if C.write(fp_to, &buf[0], count) < 0 {
+				C.close(fp_to)
+				C.close(fp_from)
+				return error_with_code('cp: failed to write to $dst', int(-1))
+			}
+		}
+		from_attr := C.stat{}
+		unsafe {
+			C.stat(&char(src.str), &from_attr)
+		}
+		if C.chmod(&char(dst.str), from_attr.st_mode) < 0 {
+			C.close(fp_to)
+			C.close(fp_from)
+			return error_with_code('failed to set permissions for $dst', int(-1))
+		}
+		C.close(fp_to)
+		C.close(fp_from)
+	}
+}
+
+// vfopen returns an opened C file, given its path and open mode.
+// NB: os.vfopen is useful for compatibility with C libraries, that expect `FILE *`.
+// If you write pure V code, os.create or os.open are more convenient.
+pub fn vfopen(path string, mode string) ?&C.FILE {
+	if path.len == 0 {
+		return error('vfopen called with ""')
+	}
+	mut fp := voidptr(0)
+	$if windows {
+		fp = C._wfopen(path.to_wide(), mode.to_wide())
+	} $else {
+		fp = C.fopen(&char(path.str), &char(mode.str))
+	}
+	if isnil(fp) {
+		return error('failed to open file "$path"')
+	} else {
+		return fp
+	}
+}
+
+// fileno returns the file descriptor of an opened C file.
+pub fn fileno(cfile voidptr) int {
+	$if windows {
+		return C._fileno(cfile)
+	} $else {
+		mut cfile_casted := &C.FILE(0) // FILE* cfile_casted = 0;
+		cfile_casted = cfile
+		// Required on FreeBSD/OpenBSD/NetBSD as stdio.h defines fileno(..) with a macro
+		// that performs a field access on its argument without casting from void*.
+		return C.fileno(cfile_casted)
+	}
+}
+
+// vpopen system starts the specified command, waits for it to complete, and returns its code.
+fn vpopen(path string) voidptr {
+	// *C.FILE {
+	$if windows {
+		mode := 'rb'
+		wpath := path.to_wide()
+		return C._wpopen(wpath, mode.to_wide())
+	} $else {
+		cpath := path.str
+		return C.popen(&char(cpath), c'r')
+	}
+}
+
+fn posix_wait4_to_exit_status(waitret int) (int, bool) {
+	$if windows {
+		return waitret, false
+	} $else {
+		mut ret := 0
+		mut is_signaled := true
+		// (see man system, man 2 waitpid: C macro WEXITSTATUS section)
+		if C.WIFEXITED(waitret) {
+			ret = C.WEXITSTATUS(waitret)
+			is_signaled = false
+		} else if C.WIFSIGNALED(waitret) {
+			ret = C.WTERMSIG(waitret)
+			is_signaled = true
+		}
+		return ret, is_signaled
+	}
+}
+
+// posix_get_error_msg return error code representation in string.
+pub fn posix_get_error_msg(code int) string {
+	ptr_text := C.strerror(code) // voidptr?
+	if ptr_text == 0 {
+		return ''
+	}
+	return unsafe { tos3(ptr_text) }
+}
+
+// vpclose will close a file pointer opened with `vpopen`.
+fn vpclose(f voidptr) int {
+	$if windows {
+		return C._pclose(f)
+	} $else {
+		ret, _ := posix_wait4_to_exit_status(C.pclose(f))
+		return ret
+	}
+}
+
+// system works like `exec`, but only returns a return code.
+pub fn system(cmd string) int {
+	// if cmd.contains(';') || cmd.contains('&&') || cmd.contains('||') || cmd.contains('\n') {
+	// TODO remove panic
+	// panic(';, &&, || and \\n are not allowed in shell commands')
+	// }
+	mut ret := 0
+	$if windows {
+		// overcome bug in system & _wsystem (cmd) when first char is quote `"`
+		wcmd := if cmd.len > 1 && cmd[0] == `"` && cmd[1] != `"` { '"$cmd"' } else { cmd }
+		unsafe {
+			ret = C._wsystem(wcmd.to_wide())
+		}
+	} $else {
+		$if ios {
+			unsafe {
+				arg := [c'/bin/sh', c'-c', &byte(cmd.str), 0]
+				pid := 0
+				ret = C.posix_spawn(&pid, c'/bin/sh', 0, 0, arg.data, 0)
+				status := 0
+				ret = C.waitpid(pid, &status, 0)
+				if C.WIFEXITED(status) {
+					ret = C.WEXITSTATUS(status)
+				}
+			}
+		} $else {
+			unsafe {
+				ret = C.system(&char(cmd.str))
+			}
+		}
+	}
+	if ret == -1 {
+		print_c_errno()
+	}
+	$if !windows {
+		pret, is_signaled := posix_wait4_to_exit_status(ret)
+		if is_signaled {
+			println('Terminated by signal ${ret:2d} (' + sigint_to_signal_name(pret) + ')')
+		}
+		ret = pret
+	}
+	return ret
+}
+
+// exists returns true if `path` (file or directory) exists.
+pub fn exists(path string) bool {
+	$if windows {
+		p := path.replace('/', '\\')
+		return C._waccess(p.to_wide(), f_ok) != -1
+	} $else {
+		return C.access(&char(path.str), f_ok) != -1
+	}
+}
+
+// is_executable returns `true` if `path` is executable.
+pub fn is_executable(path string) bool {
+	$if windows {
+		// NB: https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/access-waccess?view=vs-2019
+		// i.e. there is no X bit there, the modes can be:
+		// 00 Existence only
+		// 02 Write-only
+		// 04 Read-only
+		// 06 Read and write
+		p := real_path(path)
+		return (exists(p) && p.ends_with('.exe'))
+	}
+	$if solaris {
+		statbuf := C.stat{}
+		unsafe {
+			if C.stat(&char(path.str), &statbuf) != 0 {
+				return false
+			}
+		}
+		return (int(statbuf.st_mode) & (s_ixusr | s_ixgrp | s_ixoth)) != 0
+	}
+	return C.access(&char(path.str), x_ok) != -1
+}
+
+// is_writable returns `true` if `path` is writable.
+pub fn is_writable(path string) bool {
+	$if windows {
+		p := path.replace('/', '\\')
+		return C._waccess(p.to_wide(), w_ok) != -1
+	} $else {
+		return C.access(&char(path.str), w_ok) != -1
+	}
+}
+
+// is_readable returns `true` if `path` is readable.
+pub fn is_readable(path string) bool {
+	$if windows {
+		p := path.replace('/', '\\')
+		return C._waccess(p.to_wide(), r_ok) != -1
+	} $else {
+		return C.access(&char(path.str), r_ok) != -1
+	}
+}
+
+// rm removes file in `path`.
+pub fn rm(path string) ? {
+	mut rc := 0
+	$if windows {
+		rc = C._wremove(path.to_wide())
+	} $else {
+		rc = C.remove(&char(path.str))
+	}
+	if rc == -1 {
+		return error('Failed to remove "$path": ' + posix_get_error_msg(C.errno))
+	}
+	// C.unlink(path.cstr())
+}
+
+// rmdir removes a specified directory.
+pub fn rmdir(path string) ? {
+	$if windows {
+		rc := C.RemoveDirectory(path.to_wide())
+		if rc == 0 {
+			// https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-removedirectorya - 0 is failure
+			return error('Failed to remove "$path": ' + posix_get_error_msg(C.errno))
+		}
+	} $else {
+		rc := C.rmdir(&char(path.str))
+		if rc == -1 {
+			return error(posix_get_error_msg(C.errno))
+		}
+	}
+}
+
+// print_c_errno will print the current value of `C.errno`.
+fn print_c_errno() {
+	e := C.errno
+	se := unsafe { tos_clone(&byte(C.strerror(e))) }
+	println('errno=$e err=$se')
+}
+
+// get_raw_line returns a one-line string from stdin along with '\n' if there is any.
+pub fn get_raw_line() string {
+	$if windows {
+		unsafe {
+			max_line_chars := 256
+			buf := malloc_noscan(max_line_chars * 2)
+			h_input := C.GetStdHandle(C.STD_INPUT_HANDLE)
+			mut bytes_read := u32(0)
+			if is_atty(0) > 0 {
+				x := C.ReadConsole(h_input, buf, max_line_chars * 2, &bytes_read, 0)
+				if !x {
+					return tos(buf, 0)
+				}
+				return string_from_wide2(&u16(buf), int(bytes_read))
+			}
+			mut offset := 0
+			for {
+				pos := buf + offset
+				res := C.ReadFile(h_input, pos, 1, C.LPDWORD(&bytes_read), 0)
+				if !res && offset == 0 {
+					return tos(buf, 0)
+				}
+				if !res || bytes_read == 0 {
+					break
+				}
+				if *pos == `\n` || *pos == `\r` {
+					offset++
+					break
+				}
+				offset++
+			}
+			return buf.vstring_with_len(offset)
+		}
+	} $else {
+		max := size_t(0)
+		buf := &char(0)
+		nr_chars := unsafe { C.getline(&buf, &max, C.stdin) }
+		return unsafe { tos(&byte(buf), if nr_chars < 0 { 0 } else { nr_chars }) }
+	}
+}
+
+// get_raw_stdin will get the raw input from stdin.
+pub fn get_raw_stdin() []byte {
+	$if windows {
+		unsafe {
+			block_bytes := 512
+			mut old_size := block_bytes
+			mut buf := malloc_noscan(block_bytes)
+			h_input := C.GetStdHandle(C.STD_INPUT_HANDLE)
+			mut bytes_read := 0
+			mut offset := 0
+			for {
+				pos := buf + offset
+				res := C.ReadFile(h_input, pos, block_bytes, C.LPDWORD(&bytes_read), 0)
+				offset += bytes_read
+				if !res {
+					break
+				}
+				new_size := offset + block_bytes + (block_bytes - bytes_read)
+				buf = realloc_data(buf, old_size, new_size)
+				old_size = new_size
+			}
+			return array{
+				element_size: 1
+				data: voidptr(buf)
+				len: offset
+				cap: offset
+			}
+		}
+	} $else {
+		max := size_t(0)
+		buf := &char(0)
+		nr_chars := unsafe { C.getline(&buf, &max, C.stdin) }
+		return array{
+			element_size: 1
+			data: voidptr(buf)
+			len: if nr_chars < 0 { 0 } else { nr_chars }
+			cap: int(max)
+		}
+	}
+}
+
+// read_file_array reads an array of `T` values from file `path`.
+pub fn read_file_array<T>(path string) []T {
+	a := T{}
+	tsize := int(sizeof(a))
+	// prepare for reading, get current file size
+	mut fp := vfopen(path, 'rb') or { return []T{} }
+	C.fseek(fp, 0, C.SEEK_END)
+	fsize := C.ftell(fp)
+	C.rewind(fp)
+	// read the actual data from the file
+	len := fsize / tsize
+	buf := unsafe { malloc_noscan(int(fsize)) }
+	nread := C.fread(buf, tsize, len, fp)
+	C.fclose(fp)
+	return unsafe {
+		array{
+			element_size: tsize
+			data: buf
+			len: int(nread)
+			cap: int(len)
+		}
+	}
+}
+
+pub fn on_segfault(f voidptr) {
+	$if windows {
+		return
+	}
+	$if macos {
+		C.printf(c'TODO')
+		/*
+		mut sa := C.sigaction{}
+		C.memset(&sa, 0, sizeof(C.sigaction_size))
+		C.sigemptyset(&sa.sa_mask)
+		sa.sa_sigaction = f
+		sa.sa_flags = C.SA_SIGINFO
+		C.sigaction(C.SIGSEGV, &sa, 0)
+		*/
+	}
+}
+
+// executable returns the path name of the executable that started the current
+// process.
+[manualfree]
+pub fn executable() string {
+	$if linux {
+		mut xresult := vcalloc_noscan(max_path_len)
+		count := C.readlink(c'/proc/self/exe', &char(xresult), max_path_len)
+		if count < 0 {
+			eprintln('os.executable() failed at reading /proc/self/exe to get exe path')
+			return executable_fallback()
+		}
+		return unsafe { xresult.vstring() }
+	}
+	$if windows {
+		max := 512
+		size := max * 2 // max_path_len * sizeof(wchar_t)
+		mut result := unsafe { &u16(vcalloc_noscan(size)) }
+		len := C.GetModuleFileName(0, result, max)
+		// determine if the file is a windows symlink
+		attrs := C.GetFileAttributesW(result)
+		is_set := attrs & 0x400 // FILE_ATTRIBUTE_REPARSE_POINT
+		if is_set != 0 { // it's a windows symlink
+			// gets handle with GENERIC_READ, FILE_SHARE_READ, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0
+			file := C.CreateFile(result, 0x80000000, 1, 0, 3, 0x80, 0)
+			if file != voidptr(-1) {
+				final_path := unsafe { &u16(vcalloc_noscan(size)) }
+				// https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfinalpathnamebyhandlew
+				final_len := C.GetFinalPathNameByHandleW(file, final_path, size, 0)
+				if final_len < size {
+					ret := unsafe { string_from_wide2(final_path, final_len) }
+					// remove '\\?\' from beginning (see link above)
+					return ret[4..]
+				} else {
+					eprintln('os.executable() saw that the executable file path was too long')
+				}
+			}
+			C.CloseHandle(file)
+		}
+		return unsafe { string_from_wide2(result, len) }
+	}
+	$if macos {
+		mut result := vcalloc_noscan(max_path_len)
+		pid := C.getpid()
+		ret := proc_pidpath(pid, result, max_path_len)
+		if ret <= 0 {
+			eprintln('os.executable() failed at calling proc_pidpath with pid: $pid . proc_pidpath returned $ret ')
+			return executable_fallback()
+		}
+		return unsafe { result.vstring() }
+	}
+	$if freebsd {
+		mut result := vcalloc_noscan(max_path_len)
+		mib := [1 /* CTL_KERN */, 14 /* KERN_PROC */, 12 /* KERN_PROC_PATHNAME */, -1]
+		size := max_path_len
+		unsafe { C.sysctl(mib.data, 4, result, &size, 0, 0) }
+		return unsafe { result.vstring() }
+	}
+	// "Sadly there is no way to get the full path of the executed file in OpenBSD."
+	$if openbsd {
+	}
+	$if solaris {
+	}
+	$if haiku {
+	}
+	$if netbsd {
+		mut result := vcalloc_noscan(max_path_len)
+		count := C.readlink(c'/proc/curproc/exe', &char(result), max_path_len)
+		if count < 0 {
+			eprintln('os.executable() failed at reading /proc/curproc/exe to get exe path')
+			return executable_fallback()
+		}
+		return unsafe { result.vstring_with_len(count) }
+	}
+	$if dragonfly {
+		mut result := vcalloc_noscan(max_path_len)
+		count := C.readlink(c'/proc/curproc/file', &char(result), max_path_len)
+		if count < 0 {
+			eprintln('os.executable() failed at reading /proc/curproc/file to get exe path')
+			return executable_fallback()
+		}
+		return unsafe { result.vstring_with_len(count) }
+	}
+	return executable_fallback()
+}
+
+// is_dir returns a `bool` indicating whether the given `path` is a directory.
+pub fn is_dir(path string) bool {
+	$if windows {
+		w_path := path.replace('/', '\\')
+		attr := C.GetFileAttributesW(w_path.to_wide())
+		if attr == u32(C.INVALID_FILE_ATTRIBUTES) {
+			return false
+		}
+		if int(attr) & C.FILE_ATTRIBUTE_DIRECTORY != 0 {
+			return true
+		}
+		return false
+	} $else {
+		statbuf := C.stat{}
+		if unsafe { C.stat(&char(path.str), &statbuf) } != 0 {
+			return false
+		}
+		// ref: https://code.woboq.org/gcc/include/sys/stat.h.html
+		val := int(statbuf.st_mode) & s_ifmt
+		return val == s_ifdir
+	}
+}
+
+// is_link returns a boolean indicating whether `path` is a link.
+pub fn is_link(path string) bool {
+	$if windows {
+		path_ := path.replace('/', '\\')
+		attr := C.GetFileAttributesW(path_.to_wide())
+		return int(attr) != int(C.INVALID_FILE_ATTRIBUTES) && (attr & 0x400) != 0
+	} $else {
+		statbuf := C.stat{}
+		if C.lstat(&char(path.str), &statbuf) != 0 {
+			return false
+		}
+		return int(statbuf.st_mode) & s_ifmt == s_iflnk
+	}
+}
+
+// chdir changes the current working directory to the new directory in `path`.
+pub fn chdir(path string) {
+	$if windows {
+		C._wchdir(path.to_wide())
+	} $else {
+		_ = C.chdir(&char(path.str))
+	}
+}
+
+// getwd returns the absolute path of the current directory.
+pub fn getwd() string {
+	$if windows {
+		max := 512 // max_path_len * sizeof(wchar_t)
+		unsafe {
+			buf := &u16(vcalloc_noscan(max * 2))
+			if C._wgetcwd(buf, max) == 0 {
+				free(buf)
+				return ''
+			}
+			return string_from_wide(buf)
+		}
+	} $else {
+		buf := vcalloc_noscan(max_path_len)
+		unsafe {
+			if C.getcwd(&char(buf), max_path_len) == 0 {
+				free(buf)
+				return ''
+			}
+			return buf.vstring()
+		}
+	}
+}
+
+// real_path returns the full absolute path for fpath, with all relative ../../, symlinks and so on resolved.
+// See http://pubs.opengroup.org/onlinepubs/9699919799/functions/realpath.html
+// Also https://insanecoding.blogspot.com/2007/11/pathmax-simply-isnt.html
+// and https://insanecoding.blogspot.com/2007/11/implementing-realpath-in-c.html
+// NB: this particular rabbit hole is *deep* ...
+[manualfree]
+pub fn real_path(fpath string) string {
+	mut res := ''
+	$if windows {
+		size := max_path_len * 2
+		// gets handle with GENERIC_READ, FILE_SHARE_READ, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0
+		// use C.CreateFile(fpath.to_wide(), 0x80000000, 1, 0, 3, 0x80, 0) instead of  get_file_handle
+		// try to open the file to get symbolic link path
+		file := C.CreateFile(fpath.to_wide(), 0x80000000, 1, 0, 3, 0x80, 0)
+		if file != voidptr(-1) {
+			mut fullpath := unsafe { &u16(vcalloc_noscan(size)) }
+			// https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfinalpathnamebyhandlew
+			final_len := C.GetFinalPathNameByHandleW(file, fullpath, size, 0)
+			C.CloseHandle(file)
+			if final_len < size {
+				rt := unsafe { string_from_wide2(fullpath, final_len) }
+				res = rt[4..]
+			} else {
+				unsafe { free(fullpath) }
+				eprintln('os.real_path() saw that the file path was too long')
+				return fpath.clone()
+			}
+		} else {
+			// if it is not a file C.CreateFile doesn't gets a file handle, use GetFullPath instead
+			mut fullpath := unsafe { &u16(vcalloc_noscan(max_path_len * 2)) }
+			// TODO: check errors if path len is not enough
+			ret := C.GetFullPathName(fpath.to_wide(), max_path_len, fullpath, 0)
+			if ret == 0 {
+				unsafe { free(fullpath) }
+				return fpath.clone()
+			}
+			res = unsafe { string_from_wide(fullpath) }
+		}
+	} $else {
+		mut fullpath := vcalloc_noscan(max_path_len)
+		ret := &char(C.realpath(&char(fpath.str), &char(fullpath)))
+		if ret == 0 {
+			unsafe { free(fullpath) }
+			return fpath.clone()
+		}
+		res = unsafe { fullpath.vstring() }
+	}
+	unsafe { normalize_drive_letter(res) }
+	return res
+}
+
+[direct_array_access; manualfree; unsafe]
+fn normalize_drive_letter(path string) {
+	$if !windows {
+		return
+	}
+	// normalize_drive_letter is needed, because
+	// a path like c:\nv\.bin (note the small `c`) in %PATH,
+	// is NOT recognized by cmd.exe (and probably other programs too)...
+	// Capital drive letters do work fine.
+	if path.len > 2 && path[0] >= `a` && path[0] <= `z` && path[1] == `:`
+		&& path[2] == path_separator[0] {
+		unsafe {
+			x := &path.str[0]
+			(*x) = *x - 32
+		}
+	}
+}
+
+// fork will fork the current system process and return the pid of the fork.
+pub fn fork() int {
+	mut pid := -1
+	$if !windows {
+		pid = C.fork()
+	}
+	$if windows {
+		panic('os.fork not supported in windows') // TODO
+	}
+	return pid
+}
+
+// wait blocks the calling process until one of its child processes exits or a signal is received.
+// After child process terminates, parent continues its execution after wait system call instruction.
+pub fn wait() int {
+	mut pid := -1
+	$if !windows {
+		pid = C.wait(0)
+	}
+	$if windows {
+		panic('os.wait not supported in windows') // TODO
+	}
+	return pid
+}
+
+// file_last_mod_unix returns the "last modified" time stamp of file in `path`.
+pub fn file_last_mod_unix(path string) int {
+	attr := C.stat{}
+	// # struct stat attr;
+	unsafe { C.stat(&char(path.str), &attr) }
+	// # stat(path.str, &attr);
+	return attr.st_mtime
+	// # return attr.st_mtime ;
+}
+
+// flush will flush the stdout buffer.
+pub fn flush() {
+	C.fflush(C.stdout)
+}
+
+// chmod change file access attributes of `path` to `mode`.
+// Octals like `0o600` can be used.
+pub fn chmod(path string, mode int) {
+	if C.chmod(&char(path.str), mode) != 0 {
+		panic('chmod failed: ' + posix_get_error_msg(C.errno))
+	}
+}
+
+// chown changes the owner and group attributes of `path` to `owner` and `group`.
+pub fn chown(path string, owner int, group int) ? {
+	$if windows {
+		return error('os.chown() not implemented for Windows')
+	} $else {
+		if C.chown(&char(path.str), owner, group) != 0 {
+			return error_with_code(posix_get_error_msg(C.errno), C.errno)
+		}
+	}
+}
+
+// open_append opens `path` file for appending.
+pub fn open_append(path string) ?File {
+	mut file := File{}
+	$if windows {
+		wpath := path.replace('/', '\\').to_wide()
+		mode := 'ab'
+		file = File{
+			cfile: C._wfopen(wpath, mode.to_wide())
+		}
+	} $else {
+		cpath := path.str
+		file = File{
+			cfile: C.fopen(&char(cpath), c'ab')
+		}
+	}
+	if isnil(file.cfile) {
+		return error('failed to create(append) file "$path"')
+	}
+	file.is_opened = true
+	return file
+}
+
+// execvp - loads and executes a new child process, *in place* of the current process.
+// The child process executable is located in `cmdpath`.
+// The arguments, that will be passed to it are in `args`.
+// NB: this function will NOT return when successfull, since
+// the child process will take control over execution.
+pub fn execvp(cmdpath string, args []string) ? {
+	mut cargs := []&char{}
+	cargs << &char(cmdpath.str)
+	for i in 0 .. args.len {
+		cargs << &char(args[i].str)
+	}
+	cargs << &char(0)
+	mut res := int(0)
+	$if windows {
+		res = C._execvp(&char(cmdpath.str), cargs.data)
+	} $else {
+		res = C.execvp(&char(cmdpath.str), cargs.data)
+	}
+	if res == -1 {
+		return error_with_code(posix_get_error_msg(C.errno), C.errno)
+	}
+	// just in case C._execvp returned ... that happens on windows ...
+	exit(res)
+}
+
+// execve - loads and executes a new child process, *in place* of the current process.
+// The child process executable is located in `cmdpath`.
+// The arguments, that will be passed to it are in `args`.
+// You can pass environment variables to through `envs`.
+// NB: this function will NOT return when successfull, since
+// the child process will take control over execution.
+pub fn execve(cmdpath string, args []string, envs []string) ? {
+	mut cargv := []&char{}
+	mut cenvs := []&char{}
+	cargv << &char(cmdpath.str)
+	for i in 0 .. args.len {
+		cargv << &char(args[i].str)
+	}
+	for i in 0 .. envs.len {
+		cenvs << &char(envs[i].str)
+	}
+	cargv << &char(0)
+	cenvs << &char(0)
+	mut res := int(0)
+	$if windows {
+		res = C._execve(&char(cmdpath.str), cargv.data, cenvs.data)
+	} $else {
+		res = C.execve(&char(cmdpath.str), cargv.data, cenvs.data)
+	}
+	// NB: normally execve does not return at all.
+	// If it returns, then something went wrong...
+	if res == -1 {
+		return error_with_code(posix_get_error_msg(C.errno), C.errno)
+	}
+}