def install_bash_completion(self, script_name=None, dest="<STR_LIT>"):
if '<STR_LIT>' in os.environ and '<STR_LIT>' not in os.environ:<EOL><INDENT>os.environ['<STR_LIT>'] = os.environ['<STR_LIT>']<EOL><DEDENT>dest = expanduser(dest)<EOL>if script_name is None:<EOL><INDENT>script_name = sys.argv[<NUM_LIT:0>]<EOL><DEDENT>self.uninstall_bash_completion(script_name=script_name, dest=dest)<EOL>with open(dest, '<STR_LIT:a>') as f:<EOL><INDENT>f.write('<STR_LIT>' % script_name)<EOL><DEDENT>
add line to activate bash_completion for given script_name into dest

        You can use this for letting the user install bash_completion::

            from argdeco import command, main

            @command("install-bash-completion",
                arg('--dest', help="destination", default="~/.bashrc")
            )
            def install_bash_completion(dest):
                main.install_bash_completion(dest=dest)