SYNOPSIS
#include <netdb.h>
extern int h_errno;
DESCRIPTION
The h_errno variable is used by the name resolution functions to return error values. The value of h_errno is defined only after a call to a function for which it is explicitly stated to be set and until it is changed by the next function call. The value of h_errno should only be examined when it is indicated to be valid by a function's return value. Programs should obtain the definition of h_errno by the inclusion of <netdb.h>. The practice of defining h_errno in a program as
extern int h_errno;
(without including <netdb.h>) is unsupported.
It is unspecified whether h_errno is a macro or an identifier declared with external linkage. If a macro definition is suppressed in order to access the actual object, or a program defines an identifier with the name h_errno, the behavior is undefined.
The symbolic values stored in h_errno are documented in the RETURN VALUES section on all relevant pages.
CONFORMANCE
UNIX 98, with exceptions.
PORTING ISSUES
UNIX 98 allows h_errno to be declared without including <netdb.h>. This is not supported by the NuTCRACKER Platform.
AVAILABILITY
PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition
SEE ALSO
- Functions:
herror() ,hstrerror() ,perror() ,strerror()
- Miscellaneous:
- errno, sys_errlist, sys_nerr
PTC MKS Toolkit 10.5 Documentation Build 40.