Write a C function fcopy for a UNIX system that implements the following specification: fcopy(char *srefname char *destfname) if srefname is a regular file, fcopy, copies the contents of srcfname to destfname (creating destfname if needed). Use only C System functions. Write a C function dcopy for a UNIX system that implements the following specification: dcopy(char *srcdir, char *destdir) if srcdir is a directory, dcopy copies all regular unhidden files from srcdir to destdir (creating destdir if needed). If destdir exists, any copied file is replaced by the new version. You may use your fcopy and C System functions.