understanding commandline

Hello.

I have programmed MFC for more than 5 years and now it is a little bit funny for me, to program for commandline and understanding ist. So dont be angry because of stupid questions.

If I have this command line:

MyProg -Channels 14 -port 8000 -service console

And the program ist named MyProg

What can I expect exactly as argc and char* argv[] at the entrypoint main:
int main(int argc, char* argv[])
{
}

And can sombody explain, why I can expect these things?

Thanks for help.

M.D.

Couldn't you just try, and print'em out?

Anyhoo:
// argc = the count of space separated "words" in the commandline:
argc = 7

// Each "word" has its own index in the argv array:
argv[0] = "MyProg"
argv[1] = "-Channels"
argv[2] = "14"
argv[3] = "-port"
argv[4] = "8000"
argv[5] = "-service"
argv[6] = "console"

argv[0] is usually the name of the program.

mwilliamson posted:

Quote:

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argv[0] is usually the name of the program

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what could it be else than the name of the program?

Quote:

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Originally posted by Guysl
what could it be else than the name of the program?

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Well, if you want to be exact you should say it is the name by which the program is called.
Example:

Code:

---

[treuss]src>cat foo.cc
#include <iostream>

int main( int argc, char* argv[] )
{
        std::cout << "argv[0] is \"" << argv[0] << "\"" << std::endl;
}
[treuss]src>g++ -o foo foo.cc
[treuss]src>ln -s foo bar
[treuss]src>./bar
argv[0] is "./bar"

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The program binary has the name "foo", but I call it via a symbolic link under the name bar.

treuss,

well, isn't a symbolic link supposed to be an alias name for
the program, which means it is a name of the program
(among other "names")?

Thank you for help.

I have never though it would be such an horror to program without MFC-Classes. I am too familliar with these classes. So the beginning is al little bit hard for me. So I dont see the wood for the threes. Sorry, for this banal question.

Your answers helped me a lot.

Thanks.

M.D.

Quote:

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Originally posted by Guysl
well, isn't a symbolic link supposed to be an alias name for the program

---

Yepp. Its an alias. So it is not the name (if there is such a thing). Point is that if you deliver software you usually expect that the binary is not renamed by the user who installs it. But you cannot rely on that argv[0] will hold exactly that name, because argv[0] could be "foo", "/usr/bin/foo", "C:\foo" or "bar".
This is of course rather academic, as I don't know why anybody would rely on argv[0] having a certain value...

Good point, treuss. :thumb: