Thread: Required Parameter Missing help

Hi, i'm new to the forum and C programming and I was wondering if someone could help me with the message "Required parameter missing" that I get when I run my program in DOS.

I'm currently working my way through the C programming language 2nd edition by Brian W. Kernighan and i've got the chapter "Character Input and Output" with no problems at all.

I've used the following code;

Code:

#include <stdio.h>

main()
{
int c;

c=getchar();
while (c != EOF) {
putchar(c);
c = getchar();
}
}

I have also tried the following code;

Code:

#include <stdio.h>

main()
{
int c;
while ((c = getchar())) !=EOF)
putchar(c);
}

I can build the code with no errors or warnings, but when I load it in DOS I get the Required Parameter Missing message.

Please can anyone help, it would be greatly appreciated.

main() isn't really legal...I assume the compiler fixed that for you though. That and the lack of a return statement. It really should be:

Code:

int main(void)
{
...

    return 0;
}

I've tried what you've told me but im still getting the sane message

Cheers for the quick reply!

Are you using the 1st or 2nd code? I just noticed that the 2nd code has too many parentheses:

((c = getchar())) !=EOF) should be ((c = getchar()) != EOF)

And should not have compiled.

Other than that there's nothing wrong...

Originally Posted by Epy

Other than that there's nothing wrong...

Should the variable "C" not get a value assigned to it sins it is declared inside a function?

How are you running this in DOS? Are you submitting it from a Windows GUI IDE? Have you tried running it from a DOS command prompt independent from the IDE? Perhaps it is your IDE that is complaining when you launch it and not the compiler.

Originally Posted by R.Hermans

Should the variable "C" not get a value assigned to it sins it is declared inside a function?

Most variables are supposed to be declared in main()...you're really supposed to avoid using globals (variables declared outside of a function) whenever possible.

Originally Posted by Epy

Most variables are supposed to be declared in main()...you're really supposed to avoid using globals (variables declared outside of a function) whenever possible.

As far as I knew a variable that is declared outside of a function is by default set to "0" when it is an integer.

Originally Posted by laserlight

Yes, but that is because the rule is that objects with static storage duration are zero initialised automatically. Variables declared in the local scope of a function, unless they are declared static, do not have static storage duration. But I do not see how this is relevant to your program.

It is not my program. I asked the question because I read that the topic starter did not assigned a value to "C".

laserlight, so knowledgeable. I figured it might be legal in one of the later standards, though I don't really know why in the hell they did this other than to cause problems. It's not like putting in a return type or a return statement is time-consuming.

I read that the topic starter did not assigned a value to "C".

I see no point in assigning a value before making this call:

Code:

c=getchar();

Originally Posted by laserlight

hmm... unfortunately, I do not read this in any of the posts before your post #5, so it does not make sense to me.

Maybe a misunderstanding here. I saw the following code in the first post of this topic:

Code:

#include <stdio.h>

main()
{
int c;
while ((c = getchar())) !=EOF)
putchar(c);
}

I am currently learning C myself from the video course VTC offers. It teaches coding according to the C99 standard and it mentioned that you should assign a value to every variable when declaring it inside a function. I am aware that it is not a must but according to the instructor in that video it is good practice.

Code:

while ((c = getchar()))

R.Hermans - do not confuse this with a test for equality. What this while loop does is assign the result of getchar to c, and then as long as c is not a null value, the loop continues.

Think of it this way: y = x = 3. 3 is assigned to x, and then that same result is assigned back to y. So placing an assignment inside a loop is like placing the end result of that assignment in the test - it's just more compact.