Linux-Misc Digest #430, Volume #21 Tue, 17 Aug 99 00:13:13 EDT
Contents:
Re: why not C++? ("Frank V. Castellucci")
Re: why not C++? (Randall Parker)
Re: Help needed configuring X windows (Ed Wilts)
Re: What I think of linux. (Donn Miller)
Re: Problem with "passwd" command (Lindoze 2000)
Re: OT: OO OSs (Re: Troll (was: why not C++?)) (M van Oosterhout)
Re: User Login? (Lindoze 2000)
Re: why not C++? (Randall Parker)
Two (and a half) WindowMaker questions (Andy Busch)
Re: Any free SQL server available? (Lindoze 2000)
Re: Internet access with ASDL (Shawn Green)
HELP:NETSCSAPE WONT SHOW MY MAIL! (Ken and Kara Plaks)
Attension: I can not instal 2nd linux in same disk ("Unknown")
Attension !!! I can not instal 2nd linux in same disk ("Unknown")
Re: [Q] Parallel port access program permission (Kaz Kylheku)
slow ppp connection (Samuel Davidoff)
----------------------------------------------------------------------------
From: "Frank V. Castellucci" <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.development.apps,comp.os.linux.development.system
Subject: Re: why not C++?
Date: Mon, 16 Aug 1999 20:50:43 -0400
Christopher B. Browne wrote in message ...
>On Mon, 16 Aug 1999 07:47:33 -0400, Frank V. Castellucci <[EMAIL PROTECTED]>
>posted:
>>But this can be managed by the Factory pattern. In addition, in a OS
>>context, the factory would
>>be the desired route for instrumentation and management.
>
>Ah, yes. The famed "patterns."
Patterns are not unique, or new. They have existed since life began. Famed?
I think not. Recognizable? You have answered that already.
>>But the right analysis and design will allow predict invarient state.
>
>In other words, if you move to C++, additional analysis and design work
>is necessary to hope that it will work.
Bzzzz! Wrong. I am of the strong point of view that ALL software development
should have a plan that includes the invarient state of (put your favorite
term here) all of the objects that participate during processing. Whether it
be assembler or Logo, if you as the architect do not know what state your
systems or sub-systems are in during use cases you will certainly have a
buggier product.
>GCC has represented a stable C compiler for many years now, and may
>be considered mature.
>
>G++ has not represented a stable C++ compiler for a terribly long time.
>There is no question of it being "mature" yet.
>
>The OS can only be as stable as the compiler is mature.
Yes, and I have seen the comments in the kernel code defering to bugs in the
compiler. We all have written "work-arounds" to overcome a weakness we may
find in our choice of compilers.
>With the C++ language standard only having stabilized in the last year, it
>hardly makes sense to criticize Linux for eschewing the use of a language
>whose definition has been in flux throughout the bulk of its lifetime.
No one is making any derogatory statements in this thread.
>To my mind, the appropriate thing to do is to
> Leave Well Enough Alone.
>
>Linux functions well enough as implemented in C.
>
>Breaking that by moving to C++, and thereby having a significant period of
>time during which Linux would *definitely* not be stable, would be a
>Very Dumb Idea.
Without any basis of how it would be a Very Dumb Idea, I won't agree with
you on these statements. I will take a moment to comment that THERE IS
CHANGE in this world. One measure of the flexibility of a system is how well
it can continue to work in the face of change. How well can it adapt to the
requirements needed to keep it usefull. I have run into these walls with
systems in many languages (including C++).
>If you want to have an OS written in C++, then it makes sense to start
>designing a C++-based OS kernel.
I think that was the original authors starting point.
Frank V. Castellucci
------------------------------
From: [EMAIL PROTECTED] (Randall Parker)
Crossposted-To: comp.os.linux.development.apps,comp.os.linux.development.system
Subject: Re: why not C++?
Date: Mon, 16 Aug 1999 19:43:39 -0700
Kaz,
I liked all your points. The hte points about the vtable remind me of
another one:
Suppose you have 3 methods in your pure virtual base class: aa(), bb(),
cc(). Then you start inheriting off it in all sorts of ways that have
various levels of inheritance hierarchy. For the purpose of notation
suppose that each inherited version of aa is numbered: aa1, aa2, aa3, and
so on. Ditto for bb (bb1, bb2, etc) and cc.
Well, you could see a class that implemented
aa1, bb1, cc1,
Then another class that inherited from that class and just overrode bb
again to make it:
aa1, bb2, cc1.
But then another class that inherited from the previous and added a new
cc:
aa1, bb2, cc2
Now here is where we see how C++ comes up short. We want to make a new
class that has
aa1, bb1, cc2.
Well, guess what? There is no way to make this new class after making
those 4 other previous classes without repeating the body of either bb1
or bb2 or cc1 or cc2.
The problem is that when each implementation of aa or bb or cc is defined
it is defined for a particular class. You then run into situations where
you have to repeat an implementation of a particular method in order to
get it in various combinations with the other implementations of other
methods in the inheritance hierarchy.
I've run into this problem more than once in C++ work. So we had to do
things like make functions and instantiate classes with constructors that
got passed lists of pointers to functions. Then you had a class that had
aa, bb, cc and each of them then called a function via a pointer that was
an object variable.
One really would like to be able to define a bunch of versions of aa, of
bb, and of cc. Then be able to instantiate objects that implemented
various combinations of those methods and have a vtable get built at time
of instantiation. That is what I most wanted.
Short of that I'd like to be able to define various classes where instead
of going:
MyDerivedClass::MyMethodAA(arg types)
{
the body of the method
}
One could preferably go:
MyPureBaseClass::MyMethodAA(arg types);
Then go
MyPureBaseClass::MyMethodAA(arg types) MyMethodAA1
{
the body of the method with AA1 style implementation
}
MyPureBaseClass::MyMethodAA(arg types) MyMethodAA2
{
a different body of the method with AA2 style implementation
}
Then be able to inherit MyFirstDefinedClass off of MyPureBaseClass to
define MyFirstDerivedClass. And then go:
MyFirstDerivedClass::MyMethodAA == MyMethodAA2
to indicate which variant of MyMethodAA should have its address stuffed
in the vtable for MyFirstDerivedClass.
But C++ can't do anything like this. Its incredibly static straitjacket
for vtable is a shame.
I think that class level variable scope control is a great idea. C needs
better ways to control the name space. C also needs all sorts of neat
little language extensions that came along in C++ that had nothing to do
with OO. Also, C++ templates (though a compiler writer's nightmare) are a
lot more flexible and powerful than #define macros. But I just find C++'s
way of constructing vtables to be far too limited.
(this message has gone on too long so I won't tell you other things I
find bad about C++)
In article <[EMAIL PROTECTED]>,
[EMAIL PROTECTED] says...
> Here is trivial example of C++ inflexibility. In C++, your concrete object has
> to implement all pure virtual methods inherited from an interface base class.
> Otherwise, invocations of that method cause a run time error (call to pure
> virtual function). In many places in the Linux, virtual methods that are not
> implemented are represented by a null pointer. The code that wants to call
> the method tests for null and bypasses. Don't want to implement poll() in your
> driver? No problem, just set it null. You can't do this in C++ code without
> compiler-specific tricks that are undefined at the language level. The
> compiler-generated virtual tables are sacred and untouchable things that are
> invisible to the programmer. The usual escape hatch is to implement the
> function, but have it return some ``I am not really implemented'' status. That
> is much more expensive since an actual dispatch has to take place.
------------------------------
From: Ed Wilts <[EMAIL PROTECTED]>
Subject: Re: Help needed configuring X windows
Date: Tue, 17 Aug 1999 02:55:25 GMT
This is a multi-part message in MIME format.
==============0E9B57A8FAEF00D8C45F4473
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
LLoyd wrote:
>
> Can anyone help
> I'm manualy configuring XFree86 using xf86config.
> I cannot seem to get the modes setup correctly as my display is far too big
> for the screen.
I don't have a lot of experience with xf86config - I prefer
Xconfigurator. See if you can use this instead. Then, configure ONLY 1
resolution, like 800x600 at 16bit. Do not use 24 bit, since it's
broken.
> I have an Axion CL1566 Monitor and an SiS6326 graphics card.
> Unfortunately I dont have the manuals for my monitor.
Here's the specs on your monitor:
http://www.psra.ie/andromeda/cl1566.html
There are a few problems with the SiS 6326 chipset. Attached is the
piece from my XF86Config file that should help you.
Cheers,
.../Ed
--
Ed Wilts
Mounds View, MN, USA
mailto:[EMAIL PROTECTED]
==============0E9B57A8FAEF00D8C45F4473
Content-Type: text/plain; charset=us-ascii;
name="XF86Config-device"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="XF86Config-device"
# Device configured by Xconfigurator:
Section "Device"
Identifier "Diamond Speedstar A50"
VendorName "Diamond"
BoardName "A50"
VideoRam 8192
Option "no_bitblt"
Option "no_imageblt"
Option "sw_cursor"
# Option "no_accel" # Use this if acceleration is causing problems
# Option "fifo_moderate"
# Option "fifo_conserv"
# Option "fifo_aggresive"
# Option "fast_vram"
# Option "pci_burst_on"
# Option "xaa_benchmark" # DON'T use with "ext_eng_queue" !!!
# Option "ext_eng_queue" # Turbo-queue. This can cause drawing
# errors, but gives some accel
# Insert Clocks lines here if appropriate
EndSection
==============0E9B57A8FAEF00D8C45F4473==
------------------------------
From: Donn Miller <[EMAIL PROTECTED]>
Crossposted-To: alt.linux,alt.linux.sux,alt.os.linux,comp.os.linux.advocacy
Subject: Re: What I think of linux.
Date: Mon, 16 Aug 1999 23:01:47 -0400
David Cummings wrote:
> was the Tandy 1000 on which I learned DOS and QBASIC. Windows 3.1 on a custom made
> 25mhz IBM compatible. Had that for 3-4 yrs and ran more than I should have. Now I
That's nothing... I had a 386/sx 16 8 megs ram which I used as
my main computer from 1991 - 1997. I ran FreeBSD 2.0.5 - 2.1.7,
Linux, and Windows 3.1 on it. I never really owned a 486... I
just went straight from the 386 to a Pentium 90. So it was a
pretty huge leap. I hated that 386, even as far back as 1993,
because it wouldn't run sh*t. But, I kept hesitating to
upgrade...
Donn
------------------------------
From: Lindoze 2000 <[EMAIL PROTECTED]>
Subject: Re: Problem with "passwd" command
Date: Mon, 16 Aug 1999 23:01:24 -0400
you will need to give us a pinch more info for anyone to solve that.
what exactly do you mean by freeze? some term emulators are overly
complicated and will freeze up you system. it could be your hardware.
you've got to provide us with
some more info.
Zhengdong Zhang wrote:
>
> To whom it may concern:
it doesnt concern anyone, really.
>
> I am using RH6.0. *Sometime* the "passwd" command acts strangely: after I
> enter the new password second time, it freezes the terminal. Actually the
> "passwd" process is waiting for the disk. After this, any process which
> involves the disk usage will be waiting for the disk. I have a RH5.0
> machine, but I don't have this problem with it. What is wrong? How can it
> be fixed?
> Any suggestion will be appreciated. Thanks.
>
> Zhengdong Zhang
> [EMAIL PROTECTED]
--
Thank you for your valuable input. Your useful answers will benifit
other users as well.
You are Linux!
########################################################
## ##
## My Experiment ##
## http://www.FusionPlant.com ##
## ##
########################################################
------------------------------
Date: Tue, 17 Aug 1999 12:58:03 +1000
From: M van Oosterhout <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.development.apps,comp.os.linux.development.system
Subject: Re: OT: OO OSs (Re: Troll (was: why not C++?))
Joshua D. Boyd wrote:
> but I've never seen stuff like corba do the things that I do with ActiveX).
>Hopefully
Have you looked at GNOME?
It is a whole desktop environment based completely on CORBA. The
most impressive thing I've seen to date is embedding a complete
full-colour vector graphics image of a lion into a speadsheet.
I intend to look at this more in the future, but concepts
behind it are amazing.
Martijn van Oosterhout
Australia
------------------------------
From: Lindoze 2000 <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.setup
Subject: Re: User Login?
Date: Mon, 16 Aug 1999 23:08:24 -0400
ah. this has been asked many times by many people in various forms and
sizes.
by default, you are not able to telnet to your linux host, not even from
the linux machines itself.
fix it.
redhat:
mv /etc/securetty /etc/securetty_orig
slack:
edit this /etc/securetty
uncomment the tty00 lines
Niann Shiang wrote:
>
> I spent so many hours trying to debug a stupid login problem. (And
> eventually, I was totally locked out from the system. This drives me
> nuts.) The login as a ordinary user works fine before. For some
> mystery reason, login always gives error message (login incorrect).
> However, when I su from root twice to another account, the password
> works fine when asked. It appears that these user accounts and
> passwords work fine once getting into the system. What caused this
> mystery login incorrect ?
--
Thank you for your valuable input. Your useful answers will benifit
other users as well.
You are Linux!
########################################################
## ##
## My Experiment ##
## http://www.FusionPlant.com ##
## ##
########################################################
------------------------------
From: [EMAIL PROTECTED] (Randall Parker)
Crossposted-To: comp.os.linux.development.apps,comp.os.linux.development.system
Subject: Re: why not C++?
Date: Mon, 16 Aug 1999 19:56:20 -0700
I think the real problem with C++ and heap memory is that too many
programmers who use C++ do not understand how much all the stuff they are
writing is fragmenting the heap.
Watching various (in many cases dangerous) programmers using C++ it has
been my experience that new seems to be more natural to them (ie they are
less likely to hesitate before using it) than is malloc. So they just use
it mad.
Also, I've seen a lot of people writing a bunch of classes where they end
up constructing a smaller object, then passing it to the constructor of a
larger one to be copied into it, and then repeating that about 5 times as
they built up bigger and bigger objects.
They don't see that they are copying data like mad. All that is hidden in
constructors. They also seem to think that doing a new on a class has no
more overhead than declaring a variable on the stack.
I think it takes far greater discipline to write good C++ than good C
even though in theory the syntax of C++ ought to encourage the users to
think more about the design and partitioning of a problem. In practice
they don't know how to partition things into objects, they thrash and
fragment the heap, and they consume way more memory and do much more
copying around of data.
And they do all this seemingly oblivious to what they are doing.
The worst I ever saw of this was when I was able to trace a piece of data
coming in on a serial device and then getting copied a dozen times into a
dozen successively instantitated objects as it got passed back up a call
tree and then got passed between two processes before finally being
formatted for display. Oh, and at each level the new object was bigger
than the object before it. The data did get scaled along the way but
maybe 2 or 3 copies were necessary. Then everyone wondered why the code
was so slow.
In article <[EMAIL PROTECTED]>, [EMAIL PROTECTED]
says...
> There are also huge disadvantages.
> C++ programs need a library for some of their more advanced language
> constructs, such as new- and delete-operators, and exception handling.
> Note that kernel memory cannot be swapped out; in a user program,
> relying on a big shared library from which not everything is used is
> no problem, but in the kernel, it is.
------------------------------
From: Andy Busch <[EMAIL PROTECTED]>
Subject: Two (and a half) WindowMaker questions
Date: Mon, 16 Aug 1999 23:03:40 -0400
Question the first:
can I disable the icons that appear when I start an app. I disabled the
miniwindows for minimized windows, but I don't want any of them down
there. I can use the drop down list from the middle mouse button, when
I need them (I do anyway).
Question the second:
How can I make my mouse accelerate faster? I can only get it up to 2.5
with WPrefs. I had it up to 8-10 in KDE.
Question the 2nd and a half-th:
Is there a Window Maker newsgroup? I know there's a mailing list, but I
prefer usenet for that sort of stuff.
Thanks much
Andy
--
Andy Busch & "Andy, sometimes I think you're strange,
The College of Wooster & and then you say something, and I
[EMAIL PROTECTED] & know for sure." - Nick D. Kost, to me
------------------------------
From: Lindoze 2000 <[EMAIL PROTECTED]>
Subject: Re: Any free SQL server available?
Date: Mon, 16 Aug 1999 23:01:52 -0400
mySQL
mSQL
posqul
WME wrote:
>
> Hi,
> Is there any free SQL server available for commercial use?
--
Thank you for your valuable input. Your useful answers will benifit
other users as well.
You are Linux!
########################################################
## ##
## My Experiment ##
## http://www.FusionPlant.com ##
## ##
########################################################
------------------------------
From: Shawn Green <[EMAIL PROTECTED]>
Subject: Re: Internet access with ASDL
Date: Mon, 16 Aug 1999 19:21:13 -0700
You're right in the fact that xDSL, in general, has slower download rates then cable
does. The BIG catch, though, is that if you live in a highly dense neighborhood,
like I do, cable can become saturated and next to worthless. For those who are
trying to decide between cable and DSL, here's the low down. The more folks in your
neighborhood that get a cable modem, the lower your bandwidth goes. The area that I
live in (Sunnyvale, CA) is very dense in population and in the heart of Silicon
Valley. You KNOW there are a lot of folks around here with cable.
This is why I've choosen DSL. That way, I will always have the bandwidth that I'm
paying for. Yeah, it does cost a bit more monthly. To me, though, it's worth
having that peice of mind knowing that I don't have to worry about whether the kids
across the street running a Quake server while I'm trying to telecommute or
otherwise work remotely.
Just my 2.5 cents.
Shawn
Young4ert wrote:
> Jerry Lynn Kreps wrote:
> >
> > "Robert J. Schweikert" wrote:
> > >
> > > My ISP may offer ASDL access in the near future, anyone using ASDL out there?
> > >
> > > Does it work with Linux?
> > >
> >
> > Works for me. My ISP supplied a Cisco 675 router programmed as a DHCP
> > server and my SuSE runs a DHCP client. I have tier one service (384Kb)
> > and my download speeds vary between 27Kb/sec and 37 Kb/sec, which is
> > about 10 times faster than my old 56Kb modem download speed.
>
> That performance of a 37Kb/s (< 5KB/s) is way too slow as compared to a
> cable modem which gives an average of 100KB/s. Let's say that you meant
> a 37KB/s, it still is slower than a cable modem. May be you need to ask
> your ISP to unlock more juice for your connection (it is like a water
> pipe that you need to turn the faucet more).
>
> --
> [EMAIL PROTECTED]
>
> PS> Remove the "4" from e-mail address to respond.
------------------------------
From: Ken and Kara Plaks <[EMAIL PROTECTED]>
Subject: HELP:NETSCSAPE WONT SHOW MY MAIL!
Date: Tue, 17 Aug 1999 03:07:26 +0000
Help!
I upgraded to netscape 4.6.1 to get 128 bit encryption. I am running
RH5.2 with KDE 1.1.1 and using a cable modem. Now my inbox will fetch
new email from the server, the little text window will increment (i.e. 3
unread, 4 Total), but I cannot see the messages on the panel. I checked
the FAQ and made sure the view->messages->all is selected, but it didn't
help. Any ideas? Please post responses, don't email them 'cause I can't
read them!
Ken
------------------------------
From: "Unknown" <[EMAIL PROTECTED]>
Subject: Attension: I can not instal 2nd linux in same disk
Date: Tue, 17 Aug 1999 03:10:09 GMT
I tried without any success .
because it is same id83 root assigned
and Redhat gave message couldn't create root partision because root partion
already
exist There is no problem create Unix root partion because Unix partision
has different Id
Try it !!!!!!!!!!
Duy D. <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> Stephen Satchell wrote:
>
> > [EMAIL PROTECTED] (Unknown) wrote in
> > <d6rt3.119$[EMAIL PROTECTED]>:
> >
> > >INSTALLATION 2 linuxes in SAME DISK I have portable PC with one HD 7Gb
> > >
> > >Because root directory already assigned to Caldera I can not create
> > >second root directory
> > >to RedHat 6
> >
> > Sure you can. It's not easy, but it can be done. All you need is a
> > separate partition (or set of partitions) to install Red Hat. This may
> > mean backing up your existing Caldera installation and repartitioning
> > your hard drive.
> >
> > Also, don't think you can load 27 different distributions. You need at
> > least one partition for each distribution, and each of those partitions
> > need to live in the bottom 1GB (or is it 2GB)
>
> Actually, it's bottom 8 GB with these recent BIOS(es).
>
>
>
>
> > of the hard drive so it
> > boots properly...unless you really like loading systems via floppy.
> >
> > That said, you can have multiple distributions.
> >
> > Now, how the file systems would play across each distribution...that
> > would be interesting.
>
------------------------------
From: "Unknown" <[EMAIL PROTECTED]>
Subject: Attension !!! I can not instal 2nd linux in same disk
Date: Tue, 17 Aug 1999 03:10:49 GMT
I tried without any success .
because it is same id83 root assigned
and Redhat gave message couldn't create root partision because root partion
already
exist There is no problem create Unix root partion because Unix partision
has different Id
Try it !!!!!!!!!!
Unknown <[EMAIL PROTECTED]> wrote in message
news:d6rt3.119$[EMAIL PROTECTED]...
> INSTALLATION 2 linuxes in SAME DISK I have portable PC with one HD 7Gb
>
> Because root directory already assigned to Caldera I can not create
second
> root directory
> to RedHat 6
>
>
>
------------------------------
From: [EMAIL PROTECTED] (Kaz Kylheku)
Crossposted-To:
comp.os.linux,comp.os.linux.development,comp.os.linux.development.apps,comp.os.linux.development.system,comp.os.linux.hardware,comp.os.linux.questions
Subject: Re: [Q] Parallel port access program permission
Date: Tue, 17 Aug 1999 04:03:46 GMT
On Tue, 17 Aug 1999 12:32:15 +0900, YANAGIHARA <[EMAIL PROTECTED]> wrote:
>Hello, everybody.
>Please tell me about Parallel port access.
>
>I made parallel port access program. When ueser is root, I
>can successfully read and write binary to parallel port.
>But when ueser is not root, ``Segmentation Fault'' occur at
>inb/outb function. Tell me how to change this program's
>permission ? Or, do I have to do another action ?
You change the ownership to the root user and enable the setuid bit which will
cause it to execute with root permissions.
Because you are cross-posting, I won't tell you how that's done. Read
the chmod man page.
------------------------------
From: Samuel Davidoff <[EMAIL PROTECTED]>
Subject: slow ppp connection
Date: Mon, 16 Aug 1999 21:49:23 -0400
I'm using chat and pppd to connect to my ISP through my USRobitcs 56k
modem on LinuxPPC. My problem is my connection seems slower than it is
on the mac side.
I have /dev/ttyS0 set to 230400 baud through stty.
I have setserial flagged at spd_vhi (though this isn't neccesary)
My pppd options include '115200' (for some reason 230400 won't work),
'crtscts' and 'bsd_cmp 15,15' i think these are the relevant settings.
the chat log reports that i am connection above 50000 so i'm guessing
the problem is with pppd.
so, any ideas what the problem could be?
btw, does anyone know a reliable way to check modem connection speeds?
I've been judging from ftp transfers, and netscape loadings.
thanks,
sam
------------------------------
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End of Linux-Misc Digest
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