Write C code to return a string from a function.

This is one of the most popular interview questions

This C program wont work!


char *myfunction(int n)
{
char buffer[20];
sprintf(buffer, "%d", n);
return retbuf;
}



This wont work either!


char *myfunc1()
{
char temp[] = "string";
return temp;
}


char *myfunc2()
{
char temp[] = {'s', 't', 'r', 'i', 'n', 'g', '\0'};
return temp;
}


int main()
{
puts(myfunc1());
puts(myfunc2());
}




The returned pointer should be to a static buffer (like static char buffer[20];), or to a buffer passed in by the caller function, or to memory obtained using malloc(), but not to a local array.

This will work


char *myfunc()
{
char *temp = "string";
return temp;
}

int main()
{
puts(someFun());
}



So will this


calling_function()
{
char *string;
return_string(&string);
printf(?\n[%s]\n?, string);
}

boolean return_string(char **mode_string /*Pointer to a pointer! */)
{
*string = (char *) malloc(100 * sizeof(char));
DISCARD strcpy((char *)*string, (char *)?Something?);
}