A question about inputting a string

**winggx** · 03-27-2010

If I need to write a program that reads a string (a person's name)
then print out the first five characters of the name, how can i do that?

for example:
johnny will output johnn

this is what I wrote

Code:

int main () {
	
	char input[5];
	
	while (scanf("%s\n",input) != EOF) {
		
		printf("%s\n",input);
		
	}

	return 0;

}

however, if the user inputs more than 5 characters, then the array for input will not be large enough to hold...
but at the same time, i can't restrict the number of characters that a user type in...
so, any hints?

**claudiu** · 03-27-2010

If you don't know how many character will be input-ed you need to read character by character and put it into a dynamically allocated string. When the string gets filled up, you reallocate more memory for it.

**winggx** · 03-27-2010

Originally Posted by claudiu

If you don't know how many character will be input-ed you need to read character by character and put it into a dynamically allocated string. When the string gets filled up, you reallocate more memory for it.

So, instead of scanf("%s\n,input), I need to use %c?
and what size of char input[] should I use inside the bracket..?

Would you mind if you can give me an example..?

oh...and I am not allowed to use the heap storeage

**tabstop** · 03-27-2010

I believe BUFSIZ is the max that one call of scanf will be able to retrieve.

**vart** · 03-28-2010

Originally Posted by winggx

but at the same time, i can't restrict the number of characters that a user type in...

but you can restrict number of chars you will read at once

Code:

char buf[100];

while(scanf("%99s", buf) == 1)
{
   printf("%s", buf);
}

**meadhikari** · 03-28-2010

Can not the problem be solved by using "pointer char String" and "loop+array" to display 5 character

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