Linux-Development-Apps Digest #327, Volume #7 Wed, 11 Apr 01 05:13:08 EDT
Contents:
Development of Server in RedHat ("Julia Donawald")
Re: How to detect memory leaks ? (Jem Berkes)
Re: Urgent!!! gdm killed mysteriously? (Peter Teuben)
Re: How to detect memory leaks ? (Chris)
Re: Development of Server in RedHat ("Philip Van Hoof")
workflow apps? (Harry George)
Re: UML (Harry George)
Re: dumping core on RH linux 6.2 (Victor Wagner)
Re: makefile ("Stella")
Re: Urgent!!! gdm killed mysteriously? ("Crystal Luo")
MySQL en RH7 ("Patty van den Berg")
Re: "Linux" Float Point Verification ("Albert Herman")
Re: LILO ("Steven J. Hathaway")
Re: Urgent!!! gdm killed mysteriously? ("Crystal Luo")
Re: Development of Server in RedHat ("Julia Donawald")
----------------------------------------------------------------------------
From: "Julia Donawald" <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.development.system
Subject: Development of Server in RedHat
Date: Wed, 11 Apr 2001 02:31:13 +0200
Hi,
till now I have only developed applications in Windows, but now I get more
and more interested in Linux, so I have installed a RedHat 7.0 Linux
Distribution on my PC. I now have to develope the following application and
need therefore some information:
1.) How to develope an internet server tool, that means I want to create a
program that receives data from a client through the internet.
2.) The data from the client I have to put in an mySQL Database.
3.) How can I make the server run all the time, when the linux-server
starts.
That means where can I find some samples or other information on these two
problems. In fact I am also really interested, if this is a complex problem
in linux and which libarys ( in C++ ) I could use to simplify my work. I
know that I can search with some searchengines, but I am a really newbie in
linux and so have no detailed idea for what to search exactly.
Thanks a lot in advance
Julia
P.S. Sorry for my bad english
------------------------------
From: Jem Berkes <[EMAIL PROTECTED]>
Subject: Re: How to detect memory leaks ?
Date: Tue, 10 Apr 2001 19:46:15 -0500
> > Others will point you at various ways to do this, I
> > expect, but there is a simple C++ approach using macros
> > and placement new: (note that this code is not very
> > tested ;) )
> >
>
> Chris,
>
> That's a good idea, thank you! I will try this out.
This method works fine, as far as I have encountered. I use the same
method for win32 programming (override new and delete operators), you
can also log to a file each allocation/deallocation if you want.
--
http://www.pc-tools.net/
DOS, Win32, Linux software
------------------------------
From: Peter Teuben <[EMAIL PROTECTED]>
Subject: Re: Urgent!!! gdm killed mysteriously?
Date: Tue, 10 Apr 2001 20:45:21 -0400
Don't forget there gdm is one of those programs that can cause
your linux box be broken into by an outsider. Especially over the
last few days I've noticed a lot of port 3879. I usually run
a program called tcplog, which dumps messages like this:
Apr 7 11:14:59 nemo tcplog: port 3879 connection attempt from
170.140.126.35
to my /var/log/messages file (redhat). Make sure your mysteriously
dead gdm is not the result of a breakin and check your drives
for funny files.
peter
Crystal Luo wrote:
>
> Hi, Eric. Thank you very much.
> I booted with 'linux-up -s' as a single user then typed 'telinit 3', then I
> logged in as root. When I keyed in the command 'startx', I got the following
> message:
>
> _FontTransSocketUNIXConnect: Can't connect: errno = 111
> Failed to set default font path 'unix/:7100'
> Fatal Server error:
> could not open default font 'fixed'
> X connection to :0.0 broken (explicit kill or server shutdown).
>
> Any idea on how to fix it? Thank you so much.
>
> Crystal
>
> ----- Original Message -----
> From: "Eric P. McCoy" <[EMAIL PROTECTED]>
> Newsgroups: comp.os.linux.development.apps
> Sent: Tuesday, April 10, 2001 1:39 PM
> Subject: Re: Urgent!!! gdm killed mysteriously?
>
> > "Crystal Luo" <[EMAIL PROTECTED]> writes:
> >
> > > This is urgent! I can boot Linux Redhat 7.0 up to the level that I can
> see
> > > "MyComputerName: login. But then the gnome desktop won't be shown, and I
> get
> > > flickering screen and the message:
> > > According to /var/run/gdm.pid, gdm was already running (xxxxpid), but
> seems
> > > to have been murdered mysteriously.
> > > Possible to fix it?
> >
> > For now, boot into single-user mode and disable gdm (it's in your init
> > scripts somewhere). Then go up to multi and figure out the problem
> > for there. In particular, make sure X is properly configured - likely
> > the X server is dying and gdm continually respawns it.
> >
> > --
> > Eric McCoy <[EMAIL PROTECTED]>
> > "Knowing that a lot of people across the world with Geocities sites
> > absolutely despise me is about the only thing that can add a positive
> > spin to this situation." - Something Awful, 1/11/2001
> "Eric P. McCoy" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]...
------------------------------
From: Chris <[EMAIL PROTECTED]>
Subject: Re: How to detect memory leaks ?
Date: Wed, 11 Apr 2001 01:02:30 +0000
Jem Berkes wrote:
>
> > > Others will point you at various ways to do this, I
> > > expect, but there is a simple C++ approach using macros
> > > and placement new: (note that this code is not very
> > > tested ;) )
> > >
[...]
> >
> > That's a good idea, thank you! I will try this out.
>
> This method works fine, as far as I have encountered. I use the same
> method for win32 programming (override new and delete operators), you
> can also log to a file each allocation/deallocation if you want.
Yeah. This may have less overhead, depending on the
application in question. It's also easier to implement in
C (unless you happen to have a generalised tree data
structure or equivalent lying around, which you may). Perl
makes it extremely easy to analyse the data; I have used
this exact strategy to good effect.
--
Chris Lightfoot -- chris at ex dash parrot dot com -- www.ex-parrot.com/~chris/
``Any person who knowingly causes a nuclear weapon test explosion
or any other nuclear explosion is guilty of an offence....''
(Nuclear Explosions Act, 1998)
------------------------------
From: "Philip Van Hoof" <[EMAIL PROTECTED]>
Subject: Re: Development of Server in RedHat
Crossposted-To: comp.os.linux.development.system
Reply-To: [EMAIL PROTECTED]
Date: Wed, 11 Apr 2001 01:17:05 GMT
> 1.) How to develope an internet server tool, that means I want to create
> a program that receives data from a client through the internet.
Check the subdir 'chapter14' of this tarbal
ftp://ftp.wrox.com/beginning/2971.tar.gz
And/or buy the book "beginning linux programming"
> 2.) The
> data from the client I have to put in an mySQL Database.
Then maybe it's not even nessesairy to build a server application
at all. With MySQL you can connect with the clients to any
online server. Just make sure that the Host permission of the
user who is going to connect to the MySQL server is set to %
and port 3306 or 3307 (not sure) on the server is open (udp/tcp).
You can use Kylix or Delphi using mysql.pas (search with google)
and for kylix there are build in possibilities for working
with mysql. Both are for rapid application development ofcourse.
If you have more time :) and you want to build good applications
you should start learning C and learn how to use the mysql
API for C or .. C++ . You van find loads of information on
API's for programming MySQL clients on mysql.com. If you are
going to build a server application between the mysql server
and the client then the server program will have to be
programmed as client of the mysql server and as server for
the actual client. Only difference is that the server must
connect to the localhost mysqld ..
So
or you use :
client -internet-> your server app -localhost-> mysqld
or
client -internet-> mysqld
> 3.) How can I
> make the server run all the time, when the linux-server starts.
This depends on your distro ..
for Redhat you have a dir called
/etc/rc.d/rc$RUNLEVEL.d/
where $RUNLEVEL is a number from 0 to 6. If your redhat
starts in X mode then this runlevel is 5. Else it's
probably runlevel 2. Runlevel 1 is single mode (when you
run LILO: linux single) and 6 is reboot and shutdown
runlevel. Redhat will start all scripts that start with
the letter S in that directory.
in pseudo code this happens at bootup :
a) get the runlevel from /etc/inittab and put it in #RUNLEVEL
b)
$MYLIST = `ls /etc/rc.d/rc$RUNLEVEL.d/S*`
for each item in $MYLIST
do
exev $item start
fi
Now .. it's a bit more complicated ..
In linux you have symlinks so the redhat folks made another dir
called /etc/rc.d/init.d where all the possible scripts resist..
Redhat has some tools that allow you to manage the startup
scripts using some gfx-gui/text-gui tools.. and to make this
possible they use symlinks (well most distro's use it) this way :
They symlink
/etc/rc.d/rc2.d/S01something to /etc/rc.d/init.d/something
if the script must be executed at startup ... and
/etc/rc.d/rc2.d/K01something to /etc/rc.d/init.d/something
if the script must not be executed but only showed in these
tools..
A symlink is NOT like a shortcut in Windows.. well actually
it is.. but its much more powerfull. It's a link to a file..
Know what.. Read the man page of ln :) "man ln"
> That means where can I find some samples or other information on these
> two problems. In fact I am also really interested, if this is a complex
> problem in linux and which libarys ( in C++ ) I could use to simplify my
So I suggest that you checkout mysql.com for API's to use with MySQL
and programming languages like C and C++ 'or' kylix and Delphi depending
how much time you get for this job. Kylix and Delphi == not much
time to learn and to develop your application. And you can port
Kylix and Delphi applications to and from windows/linux.. Also kylix
is VERY new .. http://www.borland.com/kylix and still pretty
expensive. ($1500). Or if you care more about the quality of the
application.. I suggest that you learn C/C++ and the API's which you
can fetch from mysql.com...
> work. I know that I can search with some searchengines, but I am a
> really newbie in linux and so have no detailed idea for what to search
> exactly.
> P.S. Sorry for my bad english
P.S. Sorry for "my" bad english to :-)
--
Philip van Hoof aka freax (http://www.freax.eu.org)
irc: irc.openprojects.net mailto:freax @ pandora.be
------------------------------
From: Harry George <[EMAIL PROTECTED]>
Subject: workflow apps?
Date: 10 Apr 2001 19:02:00 -0700
Looking for workflow and maybe optimized scheduling apps (lower
priority). Assume mixed *NIX, Win2k environment, with the main server
running on *NIX and distributed tasks running on anything with spare
cpu cycles. We have DQS and cron jobs and assorted scripts right now.
Need to handle:
a) fully automated task (e.g., just run a job)
b) man-in-the-loop (someone has to setup and then kick off a job)
c) manual (email to someone who emails back when done)
Some kind of management mechanisms (e.g., status monitoring) via web.
Alternatively, maybe someone knows the building blocks: How to set up
a daemon on Win2K which can be triggered from *NIX.
Searching google for these topics, I see openflow but not much info on
that. Tips and pointers?
------------------------------
From: Harry George <[EMAIL PROTECTED]>
Subject: Re: UML
Date: 10 Apr 2001 19:07:45 -0700
Argo/UML is written in Java and a bit slow. However, it tries to be a
full Rational Rose workalike.
Tcm is very feature rich, but I think it is difficult to control the
markups on lines (e.g., cardinality).
My favorite right now is Dia. It can do all of UML, though a few
pieces are a bit awkward (should improve in upcoming releases). Just
does the diagrams themselves -- no underlying model repository.
However, it exports in XML, so you could graft it onto a model
repository.
Charles Herman <[EMAIL PROTECTED]> writes:
> What are the UML tools available for Linux. Along with a list of the
> tools, I am looking for a description of the pros and cons of each tool.
>
> All information will be mightily appreciated.
>
> -charles
------------------------------
From: [EMAIL PROTECTED] (Victor Wagner)
Subject: Re: dumping core on RH linux 6.2
Date: 10 Apr 2001 09:30:44 +0400
steve burkett <[EMAIL PROTECTED]> wrote:
: i made a quick little test app that deferences a null pointer to test
: out dumping core.
: when i run the app, it gets a "segmentation fault", but no core, even
: if i run the app as superuser (root).
: why is my system not able to dump core?
Becouse it is explicitely disallowed by system configuration.
You can use ulimit command to turn it on.
: i'm using RH Linux 6.2, g++ 2.95.2, gdb 5.0
--
Journalism will kill you, but it will keep you alive while you're at it.
------------------------------
From: "Stella" <[EMAIL PROTECTED]>
Subject: Re: makefile
Date: Tue, 10 Apr 2001 22:21:27 -0400
Thanks for your reply.
Well, this source code I have is using predefines so that it can be
compatible to all the platform.
Unfortunately, previous developpers could not continue theier project and I
do not have any documentation on how to compile or build.
In addition, I'm new to Unix. :-(
-Boo
"Josef Moellers" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
Boo Song wrote:
>
> I'm trying to modify a make file and getting error message saying
> "make: *** No rule to make target `@V_ALL@', needed by `all'. Stop."
>
> I have @V_ALL@ but I don't know what @V_ALL@ is.
>
> I'm running this from my Linux machine.
> I'm very new to makefile and linux.
This looks pretty much like it's not a makefile proper but rather a
template for configure.
See if there's a "configure" script somewhere in the package and run
that.
--
Josef Möllers (Pinguinpfleger bei FSC)
If failure had no penalty success would not be a prize
-- T. Pratchett
------------------------------
From: "Crystal Luo" <[EMAIL PROTECTED]>
Subject: Re: Urgent!!! gdm killed mysteriously?
Date: Wed, 11 Apr 2001 13:17:24 +0800
Hi, thank you guys for your help. I've managed to solve the problem. My
Xserver was down, I don't know why, don't remember I've made any changes.
Anyway I've fixed it using Xconfigurator. Thank you again.
br
Crystal
"Crystal Luo" <[EMAIL PROTECTED]> wrote in message
news:9au464$94v$[EMAIL PROTECTED]...
> Dear all,
>
> This is urgent! I can boot Linux Redhat 7.0 up to the level that I can see
> "MyComputerName: login. But then the gnome desktop won't be shown, and I
get
> flickering screen and the message:
>
> According to /var/run/gdm.pid, gdm was already running (xxxxpid), but
seems
> to have been murdered mysteriously.
>
> Possible to fix it?
>
> I urgently need to do something on this platform. Please help me. Thank
you
> very much.
>
> Crystal
>
>
>
>
------------------------------
From: "Patty van den Berg" <[EMAIL PROTECTED]>
Subject: MySQL en RH7
Date: Wed, 11 Apr 2001 07:50:05 +0200
Hi,
I desperately wan't to develop some Internet-applications with PhP, Apache
and MySql on Linux.
I've installed the complete RH7 distribution, bought some nice books,
eveything allright so far...
But I've serious problems when trying to run MySQL-server.
Does anybody know how to start this.
Everything written in the install-section of the MySQL documentation on
www.mysql.com isn't relevant to the RH7-mysql rpm's.
The command "safe_mysqld..." always gives "MySQl server ended..." (in
responf to cannot connect to local MySql-server through socket..."
Any clues???
Thanks,
Tom Neijman
------------------------------
From: "Albert Herman" <[EMAIL PROTECTED]>
Subject: Re: "Linux" Float Point Verification
Date: Tue, 10 Apr 2001 21:51:41 -0700
Reply-To: "Albert Herman" <[EMAIL PROTECTED]>
Take a look at http://www.theregister.co.uk/content/2/18102.html for
details. My CIO passed it on to me, so I don't know anymore than what I
read there.
Albert.
"Raymond Toy" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> >>>>> "Albert" == Albert Herman <[EMAIL PROTECTED]> writes:
>
> Albert> My companies management is more than a bit nervous about using
Linux for
> Albert> floating point computational purposes. I'm working to
mitigate their
> Albert> concerns. I plan to port to Solaris/Sparc (know about
SparcIII problems) to
>
> What Sparc III problems are you talking about here?
>
> I'm curious.
>
> Ray
------------------------------
Date: Tue, 10 Apr 2001 22:13:26 -0800
From: "Steven J. Hathaway" <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.development.system
Subject: Re: LILO
>
With SCSI, the bootstrap hardware BIOSes usually look for SCSI
drives jumpered to unit 0 or unit 1 on the first SCSI controller. Your
message indicates that your disk is jumpered as unit 3.
On development systems,I have had success placing a LILO boot loader
and some system images on a small partition on the first bootable drive
known to the BIOSes of the computer. Then, if I wish to chain to
another
LILO boot image on another disk drive or even a logical drive in an
extended partition, it is doable. This is complex, but can facilitate
development platform boot activities.
Sincerely,
Steven J. Hathaway
------------------------------
From: "Crystal Luo" <[EMAIL PROTECTED]>
Subject: Re: Urgent!!! gdm killed mysteriously?
Date: Wed, 11 Apr 2001 16:13:43 +0800
Hi, thank you very much. I've managed to solve the problem. X server was
down, I still don't know why. I reconfigured X using Xconfigurator. Anyway
thank you very much for your help.
br,
Crystal
------------------------------
From: "Julia Donawald" <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.development.system
Subject: Re: Development of Server in RedHat
Date: Wed, 11 Apr 2001 11:06:39 +0200
Hi,
thanks a lot for your answer. I have already experience in C/C++ in Windows
systems but none in Delphi, would you than think it will be better (in my
case faster ) to develope in C++ or in Delphi or Kylix?
"Philip Van Hoof" <[EMAIL PROTECTED]> schrieb im Newsbeitrag
news:lgOA6.30663$[EMAIL PROTECTED]...
> > 1.) How to develope an internet server tool, that means I want to create
> > a program that receives data from a client through the internet.
>
> Check the subdir 'chapter14' of this tarbal
> ftp://ftp.wrox.com/beginning/2971.tar.gz
> And/or buy the book "beginning linux programming"
>
> > 2.) The
> > data from the client I have to put in an mySQL Database.
>
> Then maybe it's not even nessesairy to build a server application
> at all. With MySQL you can connect with the clients to any
> online server. Just make sure that the Host permission of the
> user who is going to connect to the MySQL server is set to %
> and port 3306 or 3307 (not sure) on the server is open (udp/tcp).
>
> You can use Kylix or Delphi using mysql.pas (search with google)
> and for kylix there are build in possibilities for working
> with mysql. Both are for rapid application development ofcourse.
> If you have more time :) and you want to build good applications
> you should start learning C and learn how to use the mysql
> API for C or .. C++ . You van find loads of information on
> API's for programming MySQL clients on mysql.com. If you are
> going to build a server application between the mysql server
> and the client then the server program will have to be
> programmed as client of the mysql server and as server for
> the actual client. Only difference is that the server must
> connect to the localhost mysqld ..
>
> So
>
> or you use :
>
> client -internet-> your server app -localhost-> mysqld
>
> or
>
> client -internet-> mysqld
>
>
> > 3.) How can I
> > make the server run all the time, when the linux-server starts.
>
> This depends on your distro ..
> for Redhat you have a dir called
> /etc/rc.d/rc$RUNLEVEL.d/
> where $RUNLEVEL is a number from 0 to 6. If your redhat
> starts in X mode then this runlevel is 5. Else it's
> probably runlevel 2. Runlevel 1 is single mode (when you
> run LILO: linux single) and 6 is reboot and shutdown
> runlevel. Redhat will start all scripts that start with
> the letter S in that directory.
>
> in pseudo code this happens at bootup :
>
> a) get the runlevel from /etc/inittab and put it in #RUNLEVEL
> b)
> $MYLIST = `ls /etc/rc.d/rc$RUNLEVEL.d/S*`
> for each item in $MYLIST
> do
> exev $item start
> fi
>
> Now .. it's a bit more complicated ..
>
> In linux you have symlinks so the redhat folks made another dir
> called /etc/rc.d/init.d where all the possible scripts resist..
> Redhat has some tools that allow you to manage the startup
> scripts using some gfx-gui/text-gui tools.. and to make this
> possible they use symlinks (well most distro's use it) this way :
>
> They symlink
> /etc/rc.d/rc2.d/S01something to /etc/rc.d/init.d/something
> if the script must be executed at startup ... and
> /etc/rc.d/rc2.d/K01something to /etc/rc.d/init.d/something
> if the script must not be executed but only showed in these
> tools..
>
> A symlink is NOT like a shortcut in Windows.. well actually
> it is.. but its much more powerfull. It's a link to a file..
> Know what.. Read the man page of ln :) "man ln"
>
> > That means where can I find some samples or other information on these
> > two problems. In fact I am also really interested, if this is a complex
> > problem in linux and which libarys ( in C++ ) I could use to simplify my
>
> So I suggest that you checkout mysql.com for API's to use with MySQL
> and programming languages like C and C++ 'or' kylix and Delphi depending
> how much time you get for this job. Kylix and Delphi == not much
> time to learn and to develop your application. And you can port
> Kylix and Delphi applications to and from windows/linux.. Also kylix
> is VERY new .. http://www.borland.com/kylix and still pretty
> expensive. ($1500). Or if you care more about the quality of the
> application.. I suggest that you learn C/C++ and the API's which you
> can fetch from mysql.com...
>
> > work. I know that I can search with some searchengines, but I am a
> > really newbie in linux and so have no detailed idea for what to search
> > exactly.
>
>
>
> > P.S. Sorry for my bad english
>
> P.S. Sorry for "my" bad english to :-)
>
>
> --
> Philip van Hoof aka freax (http://www.freax.eu.org)
> irc: irc.openprojects.net mailto:freax @ pandora.be
------------------------------
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