Command line arguments

This is a discussion on Command line arguments within the C Programming forums, part of the General Programming Boards category; </code> int main(int argc, char * argv[]) </code> Can someone tell me why there is the need of asterick for ...

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    Command line arguments

    </code>
    int main(int argc, char * argv[])
    </code>

    Can someone tell me why there is the need of asterick for char *argv[]. Does this make argv[] a pointer?

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    DESTINY BEN10's Avatar
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    argv is an array of char pointers, that's why there is an asterisk. Frankly speaking I myself doesn't know much about command line arguments, so other's reply will be more helpful.
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    msh
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    argv[] is an array of pointers to string constants.

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    Quote Originally Posted by msh View Post
    argv[] is an array of pointers to string constants.
    incorrect !

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    Registered User GL.Sam's Avatar
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    incorrect !
    How informative it is... We can only try to guess what is so incorrect about it.
    The only good is knowledge and the only evil is ignorance.
    ~Socrates

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    C++まいる!Cをこわせ! Elysia's Avatar
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    Quote Originally Posted by bvkim View Post
    incorrect !
    No, it's correct.
    It can either be seen as an array of arrays OR
    an array of pointers OR
    a pointer to a pointer.

    In C, they would all be the same in this context.
    An array of pointers would probably be the easiest to understand.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

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    hahah...

    I like GLSam's answer "How informative it is!", comment of a logical thinker.

    argv[] ??? - NO
    *argv[] <--- YES, this is what I meant

    Just kidding ! NVM!

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    Basically, it can be written as **argv or *argv[] as argv[] is equivalent to *argv.

    If *argv, it means that it takes a string.

    If **argv, it means that it takes many strings. For example you create a programme called "scan". What you do here is to firstly type in the programme's name (scan) and followed by arguments/parameters when you are using the programme.
    eg. scan -sP -PN 127.0.0.1
    So, scan is the first string, -sP is the second string and so on. if you put *argv or argv[] only, it will only read one string (most likely scan).

    int argc will tel you the position of the parameters. argc = 0 would be scan, argc = 1 would be -sP.

    If you do not understand, please ask further.

  9. #9
    C++まいる!Cをこわせ! Elysia's Avatar
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    Quote Originally Posted by valthyx View Post
    ...if you put *argv or argv[] only, it will only read one string (most likely scan)...
    More likely the entire command line. I know at least Windows doesn't parse the command-line; it simply passes everything to the program. The C runtime hacks the command-line into pieces.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

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