import os
import sys

def filelist(ptn):
    debug = False
    ptn = os.path.expanduser(ptn)
    ptn = os.path.abspath(ptn)
    if os.path.isfile(ptn):
        if os.access(ptn, os.R_OK):
            return [os.path.basename(ptn)]
        return []
    if os.path.isdir(ptn):
        # The last '/' is already chopped
        ret = []
        for root, dirs, files in os.walk(ptn):
            A = root.split(ptn, 1)
            assert A[0] == ''
            if A[1] == "":
                rel_root = ""
            else:
                rel_root = A[1][1:]
            for f in files:
                f2 = os.path.join(root, f)
                if os.path.isfile(f2):
                    if os.access(f2, os.R_OK):
                        ret.append(os.path.join(rel_root, f))
                    else:
                        if debug:
                            print >> sys.stderr, "%s is not accessible"%(f2)
                else:
                    if debug:
                        print >> sys.stderr, "%s is not a file"%(f2)
        return ret
    return []


ret = filelist("~/ucp")
print ret