gistfile1.c

char *str_replace(char *search , char *replace , char *subject)
{
	char *new_subject = NULL , *p = NULL , *old , *temp;
	int c = 0, final_size;
	
	new_subject = subject;
	//Get new size of string
	//for(p = strstr(subject , search) ; p != NULL ; p = strstr(p+strlen(search) , search))
	while((p = strstr(new_subject , search)))
	{
		new_subject += strlen(search);
		c++;
	}
	
	final_size = (strlen(replace) - strlen(search))*c + strlen(subject);
	
	printf("final size %d \n" , final_size);
	
	new_subject = (char*)malloc(final_size + 1);
	//temp = (char*)malloc(final_size + 1);
	
	strcpy(new_subject , "");
	
	old = subject;
	for(p = strstr(subject , search) ; p != NULL ; p = strstr(p+strlen(search) , search))
	{
		strncpy(new_subject + strlen(new_subject) , old , p - old);
		strcpy(new_subject + strlen(new_subject) , replace);
		old = p + strlen(search);
	}
	
	return new_subject;
}