Why is the main like this?

[waratte]

While I was creating a rougelike, I took a break and started playing with the main method. Why does it only accept two arguments or none at all? Why not 1 or three or more?

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[electrosheep]

I think you need to be a little more descriptive. You were creating a rougelike, which I have never heard of, but google was my friend and you must be talking about this. What language are you coding in?

EDIT: Actually maybe you were descriptive enough, and it's my lack of programming knowledge that's the problem. I assume you are programming in either c or c++?

EDIT: You might check this out.

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[waratte]

I think you need to be a little more descriptive. You were creating a rougelike, which I have never heard of, but google was my friend and you must be talking about this. What language are you coding in?

EDIT: Actually maybe you were descriptive enough, and it's my lack of programming knowledge that's the problem. I assume you are programming in either c or c++?

EDIT: You might check this out.

A rougelike is a genre of text based games. Take T.o.M.E. for PSP as an example. It doesn't have anything to do with my question though, I just like stories...

[electrosheep]

Yeah, you're right, it doesn't have anything to do with your question. I shouldn't have brought it up. I just saw that no one responded to your question, so I figured you must not have been clear enough. Hope that *** I linked helped.

[m0skit0]

I guess you don't know what are those arguments used for. I'll try to explain.

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int main(int argc, char* argv[])

argc is how much arguments were passed to the application.
argv[] is an array of strings of all arguments passed.

Why it does have two instead of 3 or none? Because that's the needed number of arguments to fulfill its purpose, that is, passing arguments given to the application to the application itself. The OS takes care of filling those arguments for the application to process them.

[waratte]

I guess you don't know what are those arguments used for. I'll try to explain.

Code: Select all

int main(int argc, char* argv[])

argc is how much arguments were passed to the application.
argv[] is an array of strings of all arguments passed.

Why it does have two instead of 3 or none? Because that's the needed number of arguments to fulfill its purpose, that is, passing arguments given to the application to the application itself. The OS takes care of filling those arguments for the application to process them.

I understand now, thanks m0skit0!

[FrEdDy]

I guess you don't know what are those arguments used for. I'll try to explain.

Code: Select all

int main(int argc, char* argv[])

argc is how much arguments were passed to the application.
argv[] is an array of strings of all arguments passed.

Why it does have two instead of 3 or none? Because that's the needed number of arguments to fulfill its purpose, that is, passing arguments given to the application to the application itself. The OS takes care of filling those arguments for the application to process them.

well,don't forget about char **envp,even thought nobody uses it.

[Babkock]

I guess you don't know what are those arguments used for. I'll try to explain.

Code: Select all

int main(int argc, char* argv[])

argc is how much arguments were passed to the application.
argv[] is an array of strings of all arguments passed.

Why it does have two instead of 3 or none? Because that's the needed number of arguments to fulfill its purpose, that is, passing arguments given to the application to the application itself. The OS takes care of filling those arguments for the application to process them.

I understand now, thanks m0skit0!

When you invoke your program through a terminal, you can pass arguments to argv[1], argv[2], and such by executing the command with arguments after it, separated by spaces. Say you type this into a terminal.

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$ ./prog.exe hello world

argv[0] == "./prog.exe"
argv[1] == "hello"
argv[2] == "world"
argv[3] == NULL
argv[4] == NULL

and so on. Using the above command, argc will either be 2 or 3, I can't remember, it always trips me up.

[m0skit0]

don't forget about char **envp

AFAIK that's not standard.

Using the above command, argc will either be 2 or 3, I can't remember, it always trips me up.

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