Language in C Interview Questions and Answers

Question: How to use function strdup( ) in a program?

Answer: The string function strdup( ) copies the given string to a new location. The function uses malloc( ) function to allocate space required for the duplicated string. It takes one argument a pointer to the string to be duplicated. The total number of characters present in the given string plus one bytes get allocated for the new string. As this function uses malloc( ) to allocate memory, it is the programmer�??s responsibility to deallocate the memory using free( ).
#include <stdio.h>
#include <string.h>
#include <alloc.h>

void main( )
{
char *str1, *str2 = "double";

str1 = strdup ( str2 ) ;
printf ( "%sn", str1 ) ;
free ( str1 ) ;
}