Pfthb

I have created this very simple program. My goal is to have the output say String: hello world James but I want the hello world to be malloced in my test_function. Can someone explain to me how I can make my_intro = "hello world" and name my_name = "James". This problem is revolves around how I can parse the malloc-ed char value back to my main function. This is not a duplicate of changing ints. This is parsing char *

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

void test_function(char *a_intro, char *a_name);

int main(void) 
 char *my_intro;
 char *my_name;
 test_function(my_intro, my_name);

 printf("String: %s %sn", my_intro, my_name);


void test_function(char *a_intro, char *a_name) 

 char *intro = malloc(20);
 char *name = malloc(20);
 strcpy(intro, "hello world");
 strcpy(name, "James");

 a_intro = intro;
 a_name = name;

But the error I get is:

testcode.c: In function 'main':
testcode.c:10:5: error: 'my_intro' is used uninitialized in this function [-Werr
or=uninitialized]
 test_function(my_intro, my_name);
 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
testcode.c:10:5: error: 'my_name' is used uninitialized in this function [-Werro
r=uninitialized]
cc1.exe: all warnings being treated as errors

Another possible solution which doesn't work:

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

void test_function(char *a_intro, char *a_name);

int main(void) 
 char *my_intro;
 char *my_name;
 test_function(&my_intro, &my_name);

 printf("String: %s %sn", my_intro, my_name);


void test_function(char *a_intro, char *a_name) 

 char *intro = malloc(20);
 char *name = malloc(20);
 strcpy(intro, "hello world");
 strcpy(name, "James");

 *a_intro = intro;
 *a_name = name;

Error:

testcode.c: In function 'main':
testcode.c:10:19: error: passing argument 1 of 'test_function' from incompatible
 pointer type [-Werror=incompatible-pointer-types]
 test_function(&my_intro, &my_name);
 ^
testcode.c:5:6: note: expected 'char *' but argument is of type 'char **'
 void test_function(char *a_intro, char *a_name);
 ^~~~~~~~~~~~~
testcode.c:10:30: error: passing argument 2 of 'test_function' from incompatible
 pointer type [-Werror=incompatible-pointer-types]
 test_function(&my_intro, &my_name);
 ^
testcode.c:5:6: note: expected 'char *' but argument is of type 'char **'
 void test_function(char *a_intro, char *a_name);
 ^~~~~~~~~~~~~
testcode.c: In function 'test_function':
testcode.c:22:14: error: assignment makes integer from pointer without a cast [-
Werror=int-conversion]
 *a_intro = intro;
 ^
testcode.c:23:13: error: assignment makes integer from pointer without a cast [-
Werror=int-conversion]
 *a_name = name;
 ^
cc1.exe: all warnings being treated as errors