Re: Testing anti spam software
Hello,
> But that means that Debian Developers are the way that "Linux" (the
> kernel? libc?, something else?) are deeply changing The Way Unix Works.
>
> And I just don't believe they'd do that. For one thing, they're all
> pretty busy, and making such deep changes to every new version of
> upstream would be "time consuming".
>
> Have you tried Fedora, SuSE, Slackware, etc?
My system started with a Slackware base, now heavily mofified to run
slack/RH style programs. The kernal has two flavors at least, the AC
version and the LT version. I am most familst with these. Hurrd is a
third version, but I am not that familar with it. AC (Alan Cox) and
LT (Linus Torvalds) actually have very slight differences that have an
impact on the low level functions. Libc adds to this along with
different platforms (i386, so on)
One of the classic C functions that illustrates this the best in
gethostbyname_r. Some systems require 6 arguments, others 4. POSIIX
vs SUSv2. Not having a debian system I can test means I could easily
miss a very fine detail.
Here's the man page 7 of signal:
Signal Value Action Comment
-------------------------------------------------------------------------
SIGHUP 1 A Hangup detected on controlling
terminal
or death of controlling process
SIGINT 2 A Interrupt from keyboard
SIGQUIT 3 C Quit from keyboard
SIGILL 4 C Illegal Instruction
SIGABRT 6 C Abort signal from abort(3)
SIGFPE 8 C Floating point exception
SIGKILL 9 AEF Kill signal
SIGSEGV 11 C Invalid memory reference
SIGPIPE 13 A Broken pipe: write to pipe with
no readers
SIGALRM 14 A Timer signal from alarm(2)
SIGTERM 15 A Termination signal
SIGUSR1 30,10,16 A User-defined signal 1
SIGUSR2 31,12,17 A User-defined signal 2
SIGCHLD 20,17,18 B Child stopped or terminated
SIGCONT 19,18,25 Continue if stopped
SIGSTOP 17,19,23 DEF Stop process
SIGTSTP 18,20,24 D Stop typed at tty
SIGTTIN 21,21,26 D tty input for background process
SIGTTOU 22,22,27 D tty output for background process
Next the signals not in POSIX.1 but described in SUSv2.
Signal Value Action Comment
-------------------------------------------------------------------------
SIGBUS 10,7,10 C Bus error (bad memory access)
SIGPOLL A Pollable event (Sys V). Synonym
of SIGIO
SIGPROF 27,27,29 A Profiling timer expired
SIGSYS 12,-,12 C Bad argument to routine (SVID)
SIGTRAP 5 C Trace/breakpoint trap
SIGURG 16,23,21 B Urgent condition on socket (4.2
BSD)
SIGVTALRM 26,26,28 A Virtual alarm clock (4.2 BSD)
SIGXCPU 24,24,30 C CPU time limit exceeded (4.2
BSD)
SIGXFSZ 25,25,31 C File size limit exceeded (4.2
BSD)
You'll notice that certain signals have multiple numbers. Also the
difference between POSIX and SUSv2. Such slight differences can have
very slight but dramatic results on the operations of a program.
It is important to know that all linux developers (kernel et all) are
striving to gain the best utilization of current and new hardware. At
times, this does have an impact of low level functions and their
APIs. Its really the only way to move forward and progress.
---
DynaStop: Stopping spam one dynamic IP address at a time.
http://tanaya.net/DynaStop/
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