Thread: Print Certain Line in C

What result are you getting, and how is that different from what you expect?

--
Mats

%s in scanf reads till the first white space encountered so stud.name will be
"John" not "John Brown"

use return value of scanf to see how many formats were parsed successfully

with the file structure presented you need to read firstName and lastName into 2 different buffers
you cannot read them together

to avoid problems after failed parsing - better use pair fgets/sscanf instead of fscanf

http://www.daniweb.com/forums/thread139622.html

Originally Posted by W1ck3D

Hello there!

I'm having difficulties with understanding what's happening with scanf() in combination with character formatter -%c.

Let's look at simple example:

Code:

#include <stdio.h>
int main(void)
{
  
  char c;

  scanf("%c",&c);
  scanf("%c",&c);

  system("PAUSE");	
  return 0;
}

Firstly printf() parses all newly typed data, so if I press character 'p' and then enter, the data would be: 'p','\n'.Since I provided character formatter, I'd expect that first character is taken and all additional are removed, but it seems they aren't.Now the interesting part; the 'p' seems to get assigned to variable c and new line-'\n' character is sent to input and waits to be parsed and that happens in second scanf() call.

So what's the problem?Some guys told me that I have to supply a '\n' char in first argument.

Code:

 scanf("%c\n",&c);

Thing worked, but the question is why it worked?From here I can see only a new character added, which should create a new input information(one more loop), but no.Looks like this '\n' character in this context serves as "ignore \n data coming from input" or smth?

And yes, I could use getstr(), but I'm kind of "Always the hard way" guy...

You have dug and figured out exactly how scanf() works. Good job. And yes, that's that way it works, just like the Sun rises in the East and sets in the West.

All you need is to create a function that has 3 arguments: pointer to file, string to search, size of string then you should search for the string in your text file (if you ask "how?" the answer will be "think").
goodluck