segfaults and delayed printf commands while using GWindow in loop

Question

printf("%c.\n", (getText(precrmo_menu[3]))[0]);  
char input[3];  
input[0] = (getText(precrmo_menu[3]))[0];  
printf("we lived");  
if (strcmp(input, "") != 0 && !isblank(input) && isdigit(input))  
{  
    clearMenu(precrmo_menu, precrmo_menu_length);  
    menu = 2;

}

This code prints out the first character (followed by a period and a line break) but then skips the printf("we lived"); command and hits the if statement and segfaults. When I change the condition to just

if (strcmp(input, ""))

then it again skips the printf("we lived");, hits the condition, finds it true, clears the menu, and then stalls out. If I close the window, the terminal THEN prints out "we lived".

I suppose it's helpful to indicate that this code is within an intentional infinite loop that checks for MOUSE_EVENT and KEY_EVENT. If a click is within a certain zone, it will change menus by making pieces visible/not-visible and changing an int menu that holds a different numerical value based on which menu I'm on. Also, clearMenu() is used elsewhere with no glitches (all it does is loop through the menu array and calling isVisible on them to turn them not-visible).

Furthermore, it's interesting to note that within the loop, I've got an if-else ladder to check which menu number I'm on, including an escape mechanism:

else if(getEventType(event) == KEY_PRESSED)  
{  
    menu = -1;  
}

THIS code also still executes after the program seems to stall out, and if I do press a key and get out, it also waits until the window is closed to print out "we lived"

I don't understand how that command could be held in reserve but the other printf didn't... Anyone know what's going on?

Answer 1

It doesn't really "skip" the printf statement. Instead, it just "buffers" the output (in this case, the string "we lived"), then "flushes" it at some point (e.g., when you print a newline). For more info, you may check 12.20.2 Flushing Buffers!

It's possible that you're getting a segfault because the functions isblank and isdigit, each take int as an argument and not a char array or a string. Also notice that the string input might be still missing the null character (i.e., '\0') at the end of it which might cause problems.