Installation guide

• The ll_line and ll_host manifest constants in
/usr/include/lastlog.h will change to allow their sizes to
correspond to the ut_line and ut_host fields in struct utmp and
struct utmpx.
These changes will also affect the format of the /var/adm/utmp,
/var/adm/wtmp, and /var/adm/lastlog files. The following
conversion programs will be supplied:
• /usr/lbin/wtmpconvert
• /usr/lbin/llconvert
The programs will enable you to convert your existing /var/adm/wtmp
and /var/adm/lastlog files to the new format or convert new format
files to the old format for use by existing programs. See the corresponding
reference pages for more information.
8.8 C Language long double Type Changing to 128 Bits
In a future release of Tru64 UNIX, the default size of the C language long
double type will change from 64 bits to 128 bits. This will allow
application writers to perform mathematical calculations on numbers much
larger in magnitude with more precision than possible with the current long
double type, which is treated identically to the double type. A compiler
option will be provided to allow existing source code that expects a 64-bit
long double type to continue to be compiled and executed.
The one binary incompatibility that an existing application (if linked using
the -call_shared switch) could experience with the new default is
related to the input and output of long double types. Currently, the
printf and scanf functions, and other associated functions, interpret the
format code %Lf (capital-L followed by f) as referring to a 64-bit long
double type. In a future release, the interpretation of this format code will
be changed to expect the new 128-bit data type. Programs that use this
format code will either need to be changed, or will need to be run with the
new compatibility library that will be provided. An extra step will be
necessary to cause the application to use this library, and will be documented
in the release in which the change actually takes affect.
8.9 C Library Functions and POSIX P1003.1C
As of Version 4.0 of the operating system, the following C library functions
exist in two versions due to conflicts between previous versions of Tru64
UNIX and the recent IEEE POSIX P1003.1C standard (these new interfaces
are in effect by default). The old interfaces are currently accessible by
Features and Interfaces Scheduled for Retirement 8–5