C Program to Reverse a string

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

/* Program - Reverse given string with poniters
   Author - Surendra Patil
*/

int main()
{
        char *str,*rev,*ptr,temp;
        str = (char *)malloc(10*sizeof(char));

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

        printf("String before reversing = %s len = %d \n",str,strlen(str));
        ptr = str       /* point to first character */;
        rev = ptr + (strlen(ptr)-1); /* point to last character */

        /* keep swapping the characters */
        while (ptr < rev) {
                temp = *ptr;
                *ptr = *rev;
                *rev = temp;
                ptr++;
                rev--;
        }
        printf("String after reversing = %s\n",str);
        return 0;
}
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