Detect flags arguments

This is a discussion on Detect flags arguments within the C++ Programming forums, part of the General Programming Boards category; Hi everyone. I did a program in C++ and in my program in need to detect some flags that are ...

  1. #1
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    Detect flags arguments

    Hi everyone. I did a program in C++ and in my program in need to detect some flags that are given by arguments. I did it in a very inelegant way and i wasted more than 100 lines to do that. So i'm asking if someone know some algorithm or function or have some examples how to do this ?

    Thank you very much

  2. #2
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    That would depend a lot on:
    1. What environment? OS, compiler, etc?
    2. What style and parameters are the flags/options?
    3. What is the consequence of each flag/option? Do the flags have arguments to (e.g -x=3 or -outfile=foo.txt)?

    Give some examples of what a command line for the program would look like, and a list of all options [or at least a list of a few typical ones]

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    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

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    For example this line:

    ./program -n 34 56 -i -f

    I'm programming in Linux

  4. #4
    and the Hat of Guessing tabstop's Avatar
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    So presumably you would walk through argv; if argv[i][0] is a hyphen, do a switch on argv[i][1] and process that character. You'd have to use atoi or strtol to get numbers out of "34" and "56", of course.

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    You may also want to look at "man getopt" - it's a function written specifically to support option parsing.

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    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  6. #6
    and the Hat of Guessing tabstop's Avatar
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    Quote Originally Posted by matsp View Post
    You may also want to look at "man getopt" - it's a function written specifically to support option parsing.

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    You don't want to look at my google search history for the last five minutes because I couldn't think of the name. Thanks.

  7. #7
    Cat without Hat CornedBee's Avatar
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    And there's Boost.ProgramOptions, which is IMO far superior to getopt.
    All the buzzt!
    CornedBee

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  8. #8
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    I'll second CornedBee!

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