Syntax

The default portability table values, which are built into the producer, can be expressed in the form:

char_bits            8
short_bits           16
int_bits             16
long_bits            32
signed_range         symmetric
char_type            either
ptr_int              none
ptr_fn               no
non_prototype_checks yes
multibyte            1

This illustrates the syntax for the portability table; note that all ten entries are required, even though the last four are ignored.

The decimal integer associated with each of char_bits, short_bits, int_bits and long_bits gives the minimum number of bits in the representation of each integer type on all target machines. For example, if int_bits is set to 32 the compiler will perform its checks in the knowledge that the program will not be used on a machine whose int types are represented by 16 bits although they might be represented by 32 or 64 bits.