'Get exec file of debugged program
Returns:
- full path to executable file (String)'

@memoized
def getfile(self):

    result = None
    out = self.execute_redirect('info    files')
    if (out and ('"' in out)):
        p = re.compile(".*exec    file:\\s*`(.*)'")
        m = p.search(out)
        if m:
            result = m.group(1)
        else:
            p = re.compile('Symbols    from    "([^"]*)')
            m = p.search(out)
            if m:
                result = m.group(1)
    return result
