'Read commands from an input file.
Usage: source <file>'

def do_source(self, line):

    args = line.split()
    if (len(args) != 1):
        error('usage:    source    <file>\n')
        return
    try:
        self.inputFile = open(args[0])
        while True:
            line = self.inputFile.readline()
            if (len(line) > 0):
                self.onecmd(line)
            else:
                break
    except IOError:
        error(('error    reading    file    %s\n' % args[0]))
    self.inputFile.close()
    self.inputFile = None
