An example of how you can use malloc(), realloc(), and free() to create dynamic strings.

dynamic_strings_example.c

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

int main(void) {
  // sizeof(char) is always 1, but we have it here
  // for instructional purposes
  char* full_name = malloc(sizeof(char)*strlen("Jesse Lawson")+1);

  strcpy(full_name, "Jesse Lawson");

  printf("Old value of full_name:\n");

  for(int i=0; i<strlen(full_name); i++) {
    printf("[%d] %c\n", i, full_name[i]);
  }

  // Now we will realloc the space
  full_name = realloc(full_name, sizeof(char)*strlen("Jesse Happy Bubble Fun Club Lawson")+1);

  strcpy(full_name, "Jesse Happy Bubble Fun Club Lawson");

  printf("New value of full_name:\n");

  for(int i=0; i<strlen(full_name); i++) {
    printf("[%d] %c\n", i, full_name[i]);
  }

  free(full_name);

  return 0;
}