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Full Discussion: PERL: how to tell if variable is NULL
Top Forums Shell Programming and Scripting PERL: how to tell if variable is NULL Post 34878 by WIntellect on Wednesday 19th of March 2003 12:11:47 PM
Old 03-19-2003
The function "defined" may also achieve what you require; check the usual perldoc for details.

Smilie
 

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LEARN ABOUT DEBIAN

ldns_dname_compare

ldns(3) 						     Library Functions Manual							   ldns(3)

NAME

       ldns_dname_compare, ldns_dname_interval-

SYNOPSIS

       #include <stdint.h>
       #include <stdbool.h>

       #include <ldns/ldns.h>

       int ldns_dname_compare(const ldns_rdf *dname1, const ldns_rdf *dname2);

       int ldns_dname_interval(const ldns_rdf *prev, const ldns_rdf *middle, const ldns_rdf *next);

DESCRIPTION

       ldns_dname_compare() Compares the two dname rdf's according to the algorithm for ordering in RFC4034 Section 6.
	      dname1: First dname rdf to compare
	      dname2: Second dname rdf to compare
	      Returns -1 if dname1 comes before dname2, 1 if dname1 comes after dname2, and 0 if they are equal.

       ldns_dname_interval()  check if middle lays in the interval defined by prev and next prev <= middle < next. This is usefull for nsec check-
	      ing
	      prev: the previous dname
	      middle: the dname to check
	      next: the next dname return 0 on error or unknown, -1 when middle is in the interval, +1 when not

AUTHOR

       The ldns team at NLnet Labs. Which consists out of Jelte Jansen and Miek Gieben.

REPORTING BUGS

       Please report bugs to ldns-team@nlnetlabs.nl or in our bugzilla at http://www.nlnetlabs.nl/bugs/index.html

COPYRIGHT

       Copyright (c) 2004 - 2006 NLnet Labs.

       Licensed under the BSD License. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO

       ldns_dname_is_subdomain.  And perldoc Net::DNS, RFC1034, RFC1035, RFC4033, RFC4034  and RFC4035.

REMARKS

       This manpage was automaticly generated from the ldns source code by use of Doxygen and some perl.

								    30 May 2006 							   ldns(3)
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