Custom string compare function in C

Here's a simple implementation of strcmp function of string library.
It returns -1 if the first string is less than second , 1 if second string is less than first and 0 if the strings are equal.

#include<stdio.h>
#include<stdlib.h>

int main()
{
    char *string1,*string2;   //variables to store inputs to be compared
    int ret;    //variable to collect return value
    char *temp1,*temp2;
    
    /*function prototype it takes strings to be  compared and returns value accordingly*/
    int my_strcmp(const char *temp1,const char *temp2); 
    
    string1=(char*)malloc(20);
    string2=(char*)malloc(20);
    
    temp1=string1;
    temp2=string2;
    
    printf("enter two strings to be compared  :\n");
    temp1=string1;
    temp2=string2;
    
    fgets(string1,20,stdin);      //taking input from user
    fflush(stdin);
    
    fgets(string2,20,stdin);     //taking input from user
    
    while(*temp1)
    {
        temp1++;
    }
    
    temp1--;
    
    if(*temp1=='\n')
    {
        *temp1='\0';
    }
    
    while(*temp2)
    {
        temp2++;
    }
    
    temp2--;
    
    if(*temp2=='\n')
    {
        *temp2='\0';
    }

    ret=my_strcmp(string1,string2);   
    printf("\nthe return value is  %d\n",ret);
    
    free(string1);
    free(string2);
    
    return EXIT_SUCCESS;
}

int my_strcmp(const char *temp1,const char *temp2)
{
    while(*temp1 && *temp2)
    {
        if(*temp1==*temp2)
        {
            temp1++;
            temp2++;
        }
        else
        {
            if(*temp1<*temp2)
            {
                return -1;  //returning a negative value
            }
            else
            {
                return 1;   //returning a positive value
            }
        }
    }
    return 0; //return 0 when strings are same
}