File I/O #1 trouble

[loserone+_+]

look at my different code below

#include<stdio.h>

int main()
{
      FILE *fp;
      char s[80];
      int loop = 0;
      fp = fopen("Text.txt","w");

      printf("\nEnter a few lines of text:\n");
      
      while(strlen(fgets(s,79,stdin)) > 0)
           fputs(s,fp);
    
      fclose(fp);
}

it cant working, when used 'while' but if i dont use 'while' like this
i mean not any string recorded on the Text.txt
if didnt using while, (so i can only writing at least one sentence as its equal to buffering size)

#include<stdio.h>

int main()
{
      FILE *fp;
      char s[80];
      int loop = 0;
      fp = fopen("Text.txt","w");

      printf("\nEnter a few lines of text:\n");
      
      fgets(s,79,stdin);
      fputs(s,fp);
    
      fclose(fp);
}

the string i write on the .c is recorded in the Text.txt
i wonder why?

[grumpy]

It would have been useful if you have given some description of the data you are inputting to your program. Your problem is not a general one - it depends on what data you are entering.

You are aware that fgets() leaves a trailing newline in the string? Consider what that means for strlen(fgets(...)) unless you force an end-of-file condition.

If you are aborting the program (e.g. hitting CTRL-C), the fclose() statement is never executed. File I/O is typically buffered, so that means pending output will not be physically written to the file. If the total amount of data you have entered is "small" (the notion of small is OS dependent, but probably larger than you are typing in manually) it will appear that nothing is being written to the file, since all output to the file will be dropped.

[loserone+_+]

i see.
it seems

while(strlen(fgets(s,79,stdin)) > 0)

isnt needed though,
pressing CTRL-C will closing the .txt file, and it recorded any input on the program.
before i know this method, im hitting X button on the top right window corner
ah problem solved. Thank you very much grumpy