23.14 Library Functions
Implementation-Defined Behavior for Library Functions is covered in section G.3.14 of the ANSI C Standard.
What is the null pointer constant to which the macro NULL expands? (ISO 7.1.5)
0.
How is the diagnostic printed by the assert function recognized, and what is the termination behavior of this function? (ISO 7.2)
The assert function prints the file name, line number and test expression, separated by the colon character (‘:’). It then calls the abort function.
What characters are tested for by the isalnum, isalpha, iscntrl, islower, isprint and isupper functions? (ISO 7.3.1)
| Function | Characters tested |
|---|---|
isalnum | One of the letters or digits:
isalpha or isdigit. |
isalpha | One of the letters: islower
or isupper. |
iscntrl | One of the five standard motion control
characters, backspace and alert: \f, \n,
\r, \t, \v,
\b, \a. |
islower | One of the letters ‘a’ through ‘z’. |
isprint | A graphic character or the space character:
isalnum or ispunct or
space. |
isupper | One of the letters ‘A’ through ‘Z’. |
ispunct | One of the characters: ! “ # % & ' ( ) ; < = > ? [ \ ] * + , - . / : ^ |
What values are returned by the mathematics functions after a domain errors? (ISO 7.5.1)
NaN.
Do the mathematics functions set the integer expression
errno to the value of the macro ERANGE on underflow
range errors? (ISO 7.5.1)
Yes.
Do you get a domain error or is zero returned when the
fmod function has a second argument of zero? (ISO 7.5.6.4)
Domain error.