I am only week 4 so not sure if this is a spoiler for a future problem set, (if it is let me know and I will delete) but I wanted to recreate my own get_string function because wow it was useful.

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

int main(void)
{
int string_memory = 1;
char *string = malloc(sizeof(char) * string_memory);
if (string == NULL)
{
    printf("error 1.\n");
    return 1;
}

char c;
int string_leangth = 0;
int con = 0;

printf("input: ");
while (con == 0)
{
    if (string_leangth == string_memory)
    {
        string_memory  ;
        string = realloc(string, sizeof(char) * string_memory);
        if (string == NULL)
        {
            printf("error 2.\n");
            return 2;
        }
    }
    scanf("%c", &c);
    string[string_leangth] = c;
    if (c == '\n')
    {
        string[string_leangth] = '\0';
        break;
    }
    string_leangth  ;
}

printf("output: %s\n", string);
free(string);
return 0;
}

Anyway any improvements or dumb things I may have done I would love to hear, please and thank you.