Size of string inputted by user at run-time

Question

I am fairly new to C programming language. And I am getting stuck at finding the size of string the user inputs. A sample code is below:

char * input;
int main(){

printf("Enter the string : ");
scanf("%s\n", input);

int n = (  ) // this is where i put the size of input which i need at run time for my code to work

for (int i=0; i<n; i++){
// code here 
// i create threads here 
}
for (int i=0; i<n; i++){
// code here 
// i join threads here 
}

}

So, my problem is I can't find any answers at stack overflow which deals with the size of input above.

Any help will be appreciated.

you have to allocate buffer enough to receive "any" string, then use strlen to calculate length of actually entered string — Iłya Bursov, Mar 30 '18 at 03:39
What learning material are you using that suggested `char *input; scanf("%s\n", input);` ? — M.M, Mar 30 '18 at 06:12

score 0 · Answer 1 · edited Jun 20 '20 at 09:12

strlen(char*)

In C, this is the function to find the length of a string

The following example shows the usage of strlen() function:

#include <stdio.h>
#include <string.h>

int main () {
   char str[50];
   int len;

   strcpy(str, "LOL");

   len = strlen(str);
   printf("Length of |%s| is |%d|\n", str, len);
   
   return(0);
}

And, if you want find lenght without strlen()

#include <stdio.h>

int main()
{
    char s[1000], i;

    printf("Enter a string: ");
    scanf("%s", s);

    for(i = 0; s[i] != '\0'; ++i);

    printf("Length of string: %d", i);
    return 0;
}

Size of string inputted by user at run-time

1 Answers1

strlen(char*)