Take string as input from user by %c and %s and confirm that both the strings are equal

Question

#include <stdio.h> 
#include <string.h>
int main() {  
    char str1[20];
    char *str2;
    printf("enter string \n"); **// using %c  input**
    scanf("%c",str1);
     printf(" string 1  is %s  \n",str1);

  
     printf("enter string 2 \n");
    scanf("%s",*str2); //using %s input
 
     printf(" string 1 and 2 is %c and %s \n",str1,str2);**strong text**

    int a=strcmp(str1,str2); //**comparing both**
    printf("%d",a);
    return 0; 
 }

took input from user using %c and %s then used strcmp for comparing the equality of the strings

Answer 1

• %c reads one character and doesn't add a terminating null-character, so you have to add that to use the data as string.
• Buffer must be allocated and assigned to str2 before reading something there.
• %s in scanf() requires a pointer char*, so str2 should be passed instead of *str2.
• %c in printf() requires int, not char*, so you have to deference the pointer (automatically converted from the array).

Try this:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main() {  
    char str1[20];
    char *str2;
    printf("enter string \n"); // **using %c  input**
    scanf("%c",str1);
    str1[1] = '\0'; // add terminating null-charachter
    printf(" string 1  is %s  \n",str1);

    str2 = malloc(102400); // allocate buffer
    if (str2 == NULL) return 1; // check if allocation is successful
    printf("enter string 2 \n");
    // pass correct thing
    scanf("%s",str2); //using %s input
 
    printf(" string 1 and 2 is %c and %s \n",*str1,str2); // pass correct thing for %c
    int a=strcmp(str1,str2); //**comparing both**
    printf("%d",a);
    free(str2); // free the allocated buffer
    return 0; 
}