problem with a header, please help make it better

Hi Guys,

I'm struggling with header files. I'm getting compile errors on the attached two files:

undefined reference to 'read_line'

I copied everything right out of the text book and I can't get it to compile. Any insight is greatly appreciated.

Thank you,

So where is your readline.c file?

Or wherever you've implemented

Code:

---

int read_line(char str[], int n) {
  // do stuff here to fill n chars of str and return an int
}

---

Hey Salem,

Thanks for replying. I had a tough time with the chapter that covered header files. I should have figured out my issue back then rather than simply plowing forward. I went back and reviewed the chapter but, still stumped.

All 3 files (inventory.c, readline.h, readline.c) are in the same directory. Here is the readline.c file:

Code:

---

#include <ctype.h>
#include <stdio.h>
#include "readline.h"


int read_line(char str[], int n)
{
    int ch, i=0;
    while (isspace(ch= getchar()))
        ;
    while (ch != '\n' && ch != EOF) {
        if (i < n)
            str[i++] = ch;
        ch = getchar();
    }
    str[i] = '\0';
    return i;
}

---

When I try to compile inventory.c, the error is:

C:\work\.....\inventory.o:inventory.c|| undefined reference to `read_line'

Not sure if it matters but, notice the different single quotes around `read_line'. I can't find any place in my code where I used different single quotes ` vs '.

When I try to compile readline.c, the error is:

~ undefined reference to `WinMain'


Thank you.

Your compilation command line should be something like

gcc readline.c inventory.c

Thank you. That worked. I write in code in Code::Blocks 20.03. There is probably a special way to execute multifile projects that I'm not aware of. In the future, I will use the CLI as you suggested.

You should also add debugging options on the command line. I would run gcc as:

Code:

---

gcc -Wall -Wextra -Wpedantic -g -o inventory readline.c inventory.c

---

-g adds debugging information for use by gdb

-o names the final executable, otherwise a.out is the executable name.