Jul 27
More fun with Java (scope and duplicates)
I thought this was interesting… In Java, a block scoped variable may conflict with a local variable declared later in method scope, but not previously (as shown below):
class A{ public static void main(String args[]){ {int k = 5;} int k = 12; //this is OK {int k = 22;}//this is not.... } }
This is not the same as C++ where this compiles happily:
int main(){ {int i;} int i; {int i;} return 0; }
Usually C++ has the more obscure behavior….
No commentsJul 22
Protected within Java Enums
I just noticed that java enums allow protected member variables and methods. Why is this interesting? Can you think of any code that might actually make use of a protected member in an enum (as opposed to private)? Example after the jump (warning, not practical…).
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Jul 22
SWIG, Java, and JRuby
Providing a robust, maintainable, and interactive interface to your C/C++ application can be a challenge, but I’ve found that a combination of SWIG, Java, and JRuby (or Jython if you prefer) makes for a very powerful combination.
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Nov 19
Opening a TUN Device on UNIX
Nov 15
Overview of the CCSDS Network Protocols
The CCSDS standards can be intimidating to the uninitiated, this article covers AOS, TC, COP-1, and other protocols used in space communications, how they interact, and where to find the details.
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Oct 27
RSS and mercurial
Oct 25
LDAP, PAM, SSHA, and CRYPT on RHEL 5
I’m putting this here because it took me two days to figure this out. RHEL 5 (or CentOS 5) has openLDAP broken out of the box. It does not handle SSHA password encryption (the default for openLDAP) properly. If you want openLDAP authentication to work with PAM on CentOs 5.3 you MUST edit the /etc/openldap/slapd.conf to contain:
password-hash {CRYPT}If you do not then as soon as you use ldappasswd to change a password your user will no longer be able to log in. That is all.
No commentsJul 24
Why is XML Better?
Why is XML better than custom internal formats? Isn’t a non-standard set of XML tags basically equivalent to a custom format when using data internally to an application? Absolutely not, and here is why.
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Jun 26