os: implement Getwd

src/syscall/file_hosted.go

@@ -0,0 +1,25 @@
+// +build !baremetal,!wasi,!wasm
+
+// This file assumes there is a libc available that runs on a real operating
+// system.
+
+package syscall
+
+const pathMax = 1024
+
+func Getwd() (string, error) {
+	var buf [pathMax]byte
+	s := libc_getcwd(&buf[0], uint(len(buf)))
+	if s == nil {
+		return "", getErrno()
+	}
+	n := clen(buf[:])
+	if n < 1 {
+		return "", EINVAL
+	}
+	return string(buf[:n]), nil
+}
+
+// char *getcwd(char *buf, size_t size)
+//export getcwd
+func libc_getcwd(buf *byte, size uint) *byte