How to debug apps get inputs from TTY?

[likyh]

#include <stdio.h>
int main(){
    int a, b;
    scanf("%d%d", &a, &b);
    printf("%d\n", a+b);
    return 0;
}

got:

[rohanrhu]

When you use scanf() and similars, OS sends SIGTTIN to your process and GDB shell and your app can't use the same TTY like this. Your app must use a different TTY than the one that your GDB shell is on.

Simplest way to debug apps that take inputs on TTY

Split terminal and run your app in new terminal

Attach GDB to your process

When GDB attached to your process, your process will be interrupted immediately, just click to continue

Add a breakpoint after the call that gets input from TTY and enter an input and press enter

That's all.

[likyh]

thank you~

[GitMensch]

That's very useful - What do you think about adding this to the tutorials and link that in README?

[rohanrhu]

That's very useful - What do you think about adding this to the tutorials and link that in README?

Thank you @GitMensch I will add it to docs and link in README.md.