Errata for Head First C

The first time through the while loop the condition "card_name[0] != 'X'" is reading uninitialized memory, it could find any value there including 'X' (terminating the program before any input is accepted).

Note from the Author or Editor:
The bug is in the exercise on page 35/37. The: while(card_name[0] != 'X') { ... printf("Current count: %i\n", count); } needs to be switched to a do/while loop: do { ... printf("Current count: %i\n", count); } while(card_name[0] != 'X');

The sample code for the jukebox application uses the "fgets" function to get the user's search string. However, fgets will add the newline (\n) character to the end of the string when the user presses the enter key to submit their search string. This newline character must be removed and replaced with the null character (\0) in order for it to actually match one of the song titles in the tracks[] array. Without replacing the newline character, the code as listed on this page does not work (however, the screenshot on the next page shows it functioning properly). An example fix can be used directly after the following line: fgets(search_for, 80, stdin); // FIX TO REPLACE NEWLINE CHARACTER if(search_for[strlen(search_for) - 1] == '\n') { search_for[strlen(search_for) - 1] = '\0'; }

Note from the Author or Editor:
In the code on pages 91/93/94, each time the fgets() function is called, add the following line of code after it: search_for[strlen(search_for) - 1] = '\0';