gcc - warning: implicit declaration of function 'get_int'

Question

I am doing the cs50 course and decided to run the code from there on my pc.

I have the following code:

#include "cs50.h"
#include <stdio.h>

int main(void)
{
    int n;
    do
    {
        //gets an integer from a user
        n = get_int("Height: ");
    }
    while (n < 1 || n > 8);
    for (int i = 1; i <= n; i++)
    {
        for (int j = 0; j < n * 2 + 2; j++)
        {
            //prints hashes only if j is more or equal to n - 1 
            if (j >= n - i && j <= n - 1)
            {
                printf("#");
            }
            //prints empty spaces to make the pyromide right alinged
            else if (j <= n - i)
            {
                printf(" ");
            }

            //makes empty spaces between two pyromids
            else if (j >= n - 1 && j <= n + 1)
            {
                printf(" ");
            }

            //adds hashes for the second pyromid
            else if (j >= n + 2 && j <= n + 1 + i)
            {
                printf("#");
            }

        }
        //starts a new line after finishing the code
        printf("\n");
    }
}

and when I try to compile it this happens:

gcc cs50.o mario.c -o mario.exe -std=c99 -lcs50
mario.c: In function 'main':
mario.c:10:9: warning: implicit declaration of function 'get_int' [-Wimplicit-function-declaration]
         n = get_int("Height: ");
         ^
C:/Program Files (x86)/Dev-Cpp/MinGW64/bin/../lib/gcc/x86_64-w64-mingw32/4.9.2/../../../../x86_64-w64-mingw32/bin/ld.exe: cannot find -lcs50
collect2.exe: error: ld returned 1 exit status

I am using gcc compiler on a Windows PC. I also downloaded the cs50 library from here and tried in many ways to compile and run my code.

For instance, I tried to build an intermediate file from cs50.c and cs50.h by using this line gcc -c cs50.c it created an object named cs50.o, linking it didn't work either. The last attempt to link the cs50 library with this -lcs50 did nothing as well.

I tried to use the following methods, but they too didn't work for me:

• importing C library in windows

• How to link the cs50 C library in gcc on windows

Answer 1

Jonathan Leffler As you suggested it was because of that. Thank you a lot for helping with this problem. Now compiler works and I can run the program.