C function to Swap strings

#include<stdio.h> 
void swap(char *str1, char *str2) 
{ 
char *temp = str1; 
str1 = str2; 
str2 = temp; 
} 

int main() 
{ 
char *str1 = "geeks"; 
char *str2 = "forgeeks"; 
swap(str1, str2); 
printf("str1 is %s, str2 is %s", str1, str2); 
getchar(); 
return 0; 
} 

#include<stdio.h> 

/* Swaps strings by swapping pointers */
void swap1(char **str1_ptr, char **str2_ptr) 
{ 
char *temp = *str1_ptr; 
*str1_ptr = *str2_ptr; 
*str2_ptr = temp; 
} 

int main() 
{ 
char *str1 = "geeks"; 
char *str2 = "forgeeks"; 
swap1(&str1, &str2); 
printf("str1 is %s, str2 is %s", str1, str2); 
getchar(); 
return 0; 
} 

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

/* Swaps strings by swapping data*/
void swap2(char *str1, char *str2) 
{ 
char *temp = (char *)malloc((strlen(str1) + 1) * sizeof(char)); 
strcpy(temp, str1); 
strcpy(str1, str2); 
strcpy(str2, temp); 
free(temp); 
} 

int main() 
{ 
char str1[10] = "geeks"; 
char str2[10] = "forgeeks"; 
swap2(str1, str2); 
printf("str1 is %s, str2 is %s", str1, str2); 
getchar(); 
return 0; 
}