Back in the day, Ken Thompson described a rather scary problem with the way programming languages are compiled.
In summary, one could modify the C compiler so that, when it compiled some security-critical application like sshd
, it inserted a security hole. The pristine sshd sources, when compiled, would produce a vulnerable executable. But then to protect the modification to the C compiler from being found, one can use the same trick on the compiler - make it insert the bugs into sshd and into itself when compiled from pristine sources. Compile this compiler up, then test it on its original sources, and when it's all working OK, install it on a system (and the bad sshd) and remove the dodgy sources. Clear your .bash_history
and you're done 😉
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S-expression based languages (eg, Lisps, and by a broader definition of s-expression, things like Prolog) use a single regular syntax to represent the parse tree of code, rather than having parsing rules for each syntactic construct in the language.
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As of today we have a new addition to the household - a new pet and a wiggly pet goes to the first person to guess what it is!
I will answer questions left in the comments section but only one a day so you might as well leave guesses!
🙂
Oh and its called Percival incase you hadnt guessed!
Ok here comes some abuse of our blog again, I've filched this from Random Acts of Reality blog, these paramedics are doing the three peaks challenge to raise money for Londons only childrens hospice.
I'm going to be missing my sponsered walk this year to go to a wedding so maybe people could sponser these guys instead?
Ok thats me done being cheeky - I'll be posting the picks of Jean and helicopters and Easter festivities shortly.
I like this guy's thinking on programming language design. It aligns pretty closely with my own ideas, and has some good ideas on syntax that I might borrow for CHROME...
And the way he implemented Viaweb is pretty similar to how I might have.
I think I'm more a fan of object orientation than he is, but this might just be a matter of terminology. I'm more of a fan of generic functions and Haskell-style classes than Java's OO.