参数解析

    2. This is not the answer.
    3. $ ./match_args 42
    4. This is the answer!
    5. $ ./match_args do something
    6. error: second argument not an integer
    7. match_args <string>
    8.     Check whether given string is the answer.
    9. match_args {increase|decrease} <integer>
    10.     Increase or decrease given integer by one.
    11. $ ./match_args do 42
    13. match_args <string>
    14.     Check whether given string is the answer.
    15. match_args {increase|decrease} <integer>
    16.     Increase or decrease given integer by one.
    18. 43