National Instruments 320685D-01 Non-ANSI Behavior of Sun Solaris 1 ANSI C Library, LabWindows/CVI Implements printf and scanf, Main Function Must Call InitCVIRTE

Chapter 5 UNIX Compiler/Linker Issues
LabWindows/CVI Programmer Reference Manual 5-4
© National Instruments Corporation
Non-ANSI Behavior of Sun Solaris 1 ANSI C Library
The C library that comes with Sun Solaris 1 (SunOS 4.1.x) does not comply with the ANSI C
standard as follows:
• Some ANSI C functions are missing from the library.
• Some library functions have different behavior than the ANSI standard specifies.
LabWindows/CVI corrects these problems by adding a library, libcfix.a, that
replaces and supplements the Sun Solaris library as necessary. The Solaris 1 ANSI C Libr ary
Implementation section contains more information about how LabWin do ws/CVI pro vides an
ANSI C library on Solaris 1.
LabWindows/CVI Implements printf and scanf
Although the Sun Solaris libraries provide the ANSI C family of functions for formatted input
and output (scanf, printf, and others), LabWindows/CVI provides special versions of
these functions for the following reasons:
• The LabWindows/CVI versions of these functions provide run-time error checking not
available with Sun Solaris versions.
• The Sun Solaris 1 version of these functions do not comply fully with the ANSI C
standard.
• The Sun Solaris versions of these functions do not work with the LabWindows/CVI
implementation of the long double data type.
For standalone executables, these functions come in a separate static library,
libcviprintf.a, in the lib subdirectory of the LabWindows/CVI installation directory.
When you create an executable in LabWindows/CVI, LabWindows/CVI links your prog ram
to this static library.
Main Function Must Call InitCVIRTE
If your program calls any functions from the LabWindows/CVI libraries, you must call
InitCVIRTE to initialize the libraries from the executable. This function takes three
arguments. The first and third arguments to this function must always be 0 for UNIX
applications. The second must be the same value as the second parameter of your main
function. InitCVIRTE returns 0 if it fails.
You do not have to call InitCVIRTE when you run your program in the LabWindows/CVI
development environment because LabWindows/CVI always initializes the libraries.
However, if you do not call InitCVIRTE, your executable cannot work. For this reason,
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