assert-test.c

#include <stdio.h>
#include <assert.h>


int x = 10;

int main(void)
{
    assert(x < 5);
    printf("assert test\n");

    return 0;
}

/*
❯❯❯ gcc assert-test.c && ./a.out

Assertion failed: (x < 5), function main, file assert-test.c, line 9.
[1]    3665 abort      ./a.out


❯❯❯ gcc -DNDEBUG assert-test.c && ./a.out

assert test
*/