National Instruments 320685D-01 Incompatibilities among LabWindows/CVI, Sun Solaris, and ANSI C

Chapter 5 UNIX Compiler/Linker Issues

LabWindows/CVI Programmer Reference Manual 5-10

National Instruments Corporation

Incompatibilities among LabWindows/CVI, Sun Solaris, and ANSI C

Under the ANSI C standard, the programmer who implements the library chooses how certain

functions behave. As a result, two implementations of a function can behave differently and

still conform to the ANSI standard. Because LabWindows/CVI now uses the Sun Solaris C

library, incompatibilities arise from the following sources:

• Differences between LabWindows/CVI and the ANSI standard

• Differences between LabWindows/CVI and the Sun Solaris standard

This section outlines these incompatibilities.

Note None of these incompatibilities interfere with development of projects and

standalone executables in LabWindows/CVI for Sun.

The following incompatibilities exist between LabWindows/CVI and ANSI C:

• LabWindows/CVI for Solaris 1 defines size_t as a signed integer instead of an

unsigned integer as the ANSI C standard requires. National Instruments uses the

signed integer definition to make LabWindows/CVI compatible with the Sun Solaris

headerfiles.

• LabWindows/CVI for Solaris 1 uses the Sun Solaris version of the ANSI function

strftime, which incorrectly interprets the "%W" control string as the one-based week

number instead of the zero-based week number as ANSI specifies.

• In LabWindows/CVI for Solaris 1, ungetc works improperly in certain cases:

-fsetpos fails to erase all memory of pushback characters by ungetc.

-ungetc does not clear the end-of-file indicator on success.

-ungetc fails in certain cases after reading to the end of a file.

• In LabWindows/CVI for Solaris 1, signal handlers you install with the signal function

remain installed after invocation of the handler. The ANSI standard specifies that these

handlers be removed before they are invoked.

• In standalone executables LabWindows/CVI creates for Solaris 1, the function abort

and the macro assert do not terminate the program if you install a signal handler for the

SIGABRT signal and the handler returns rather than calling longjmp. The ANSI standard

specifies that the program terminate in these cases.

• Under some versions of Sun Solaris 2 (for example, Solaris 2.5), the ANSI function

setlocale does not work properly when running programs in the LabWindows/CVI

development environment. LabWindows/CVI links programs in the development

environment to the Sun Solaris static library libc.a, which contains a limited version