Question

I have the following code:

if (!strcmp(ent_child->d_name, "eeprom")){
    printf("\tread_from_driver: found a match! ");//DEBUG
    get_child_path(child_path, child_path, "eeprom");
    printf("The path is: %s\n", child_path);//DEBUG
    read_eeprom(child_path);
}

This causes a segfault at some point, (probably get_child_path), but the first printf never happens, even though when I fix the code to be this:

if (!strcmp(ent_child->d_name, "eeprom")){
    while(1)
         printf("\tread_from_driver: found a match! ");//DEBUG
    get_child_path(child_path, child_path, "eeprom");
    printf("The path is: %s\n", child_path);//DEBUG
    read_eeprom(child_path);
}

It does happen. What’s going on? This is definitely not the first time I observed this behavior.

Answer 1

stdout is line-buffered by default, which means that you only get updated output when you send a newline character, or when you explicitly call fflush(stdout).