Programming

Compiling objective-C program using GNUStep

2009-10-29T13:36:00.000-07:00

My current OS is Fedora 10 x86_64

First what you should do it is install GNUStep. I installed it from repository. Search gnustep packages.

1. Create new project directory and add the following Objective-C source code to hello.m file:

hello.m:

#import < Foundation/Foundation.h>

int main(int argc, const char* argv[])
{
NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
NSLog(@"Hello from Hello.m!");

[pool release];
return 0;
}

2. Now create the makefile and save it in the same project directory with the filename GNUmakefile

Example:

#
# A simple GNUmakefile example for an Objective-C command line utility
#
include $(GNUSTEP_MAKEFILES)/common.make

# Build a simple Objective-C program, called Example
TOOL_NAME = Example

# The Objective-C Implementation files to compile
Example_OBJC_FILES = Main.m Some_Class.m Other_Class.m

# Class Header (Interface) files
Example_HEADER_FILES = Some_Class.h Other_Class.h

# Define the compiler flags
ADDITIONAL_CPPFLAGS = -Wall -Wno-import

# Include the rules for making Objective-C command line tools
include $(GNUSTEP_MAKEFILES)/tool.make

In our case GNUMakefile looks as follow:

include $(GNUSTEP_MAKEFILES)/common.make

TOOL_NAME = Hello
Hello_OBJC_FILES = hello.m

include $(GNUSTEP_MAKEFILES)/tool.make

3. To make makefile useful configure GNUStep:

set GNUSTEP_MAKEFILES variable to correct path to your installed GNUStep.

On most Unix systems, GNUstep is installed in /usr/lib/GNUstep. In my case it is in /usr/lib64/GNUstep

So use following command to set this variable or add it to ~/.bachrc file

export GNUSTEP_MAKEFILES=/usr/lib64/GNUstep

set your GNUstep environment variables:

The simplest way to do this is to execute following command:

source /System/Library/Makefiles/GNUstep.sh

In my case it is:

source /usr/lib64/GNUstep/Makefiles/GNUstep.sh

4. After all steps are done you can use just make command to build your objective-c project

$ make

Following output means that program was built without errors:
This is gnustep-make 2.2.0. Type 'make print-gnustep-make-help' for help.
Making all for tool Hello...
Compiling file hello.m ...
Linking tool Hello ...

That's all. Enjoy!

Grub rescue

2009-06-14T02:07:00.000-07:00

1. Load from CD and choose system rescue.

2. I've been trying to use grub-install of CD linux but it was a bad way, becuse program was asking me about dependencies which it can not found. So I propouse to use grug-install of your installed linux. For do this you need change root to your system root. For it do the following:

a) find where your installed linux (fdisk -l can help you)

b) mount your installed system root partition to (for example) /mnt/sysimage/

c) mount /proc and /dev folders to you system folders with --bind parameter:

mount --bind /proc/ /mnt/sysimage/proc/

mount --bind /dev/ /mnt/sysimage/dev/

4. and ofcourse command chroot

chroot /mnt/sysimage/

Now you can use /grub-install of your installed system

grub-install --root-directory

now it is not nessessary to set root directory, because now it is /

so:

grub-install /dev/sda6

5. reboot.

6. If after reboot you have grub menu but it is impossible to load your system - you should edit grub menu items.

7. It is very simple, just read documentation which displayed abow. In my case it was: press 'e' - to edit menu item, press 'e' to set boot device.

8. Set device in the same format as it was before: root (hd5,0) in my case for /dev/sda6 partition.

Installing Maemo onto Fedora 9 x86

2009-03-25T12:46:00.000-07:00

Installing scratchbox using the installer script

The installer script can be found from here:

Before running downloaded script I recomend to run the following commands:

Add user to your system which will be Maemo user:

#adduser tolyan
#passwd tolyan

If you use proxy, do not forget to export it:

#export http_proxy=http://proxy_user:proxy_passwd@proxy.server.com:port/

You will be asked to run these two commands by installing script, so you can do it now

#echo 0 > /proc/sys/vm/vdso_enabled
#echo 0 > /selinux/enforce

Now you can run script, also you can specify users to be added to scratchbox users with '-u USER', in out case it is tolyan:

#./maemo-scratchbox-install_4.1.2.sh -u tolyan -s /scratchbox

Start scratchbox:

#/scratchbox/sbin/sbox_ctl start

Checking the scratchbox installation

Open other terminal and login under tolyan

@su -l tolyan

try to login:

@/scratchbox/login

if login is successfull press Ctrl+D to logout

Installing Maemo 4.1.2 SDK using the installer script

To install the SDK, first download the script maemo-sdk-install_4.1.2.sh

and put it somewhere where it will be accessible to user tolyan

All following commands should be runned from tolyan user, you can do it in the same terminal where you was testing scratchbox login

Do not forget to export proxy if you need it:

@export http_proxy=http://proxy_user:proxy_passwd@proxy.server.com:port/

run installing script:

@sh maemo-sdk-install_4.1.2.sh

After that graphics menu will be shown

in menu Select Installed Packages: select Runtime Environment (it will be enough for now)
Do you wish to download and install closed Nokia Binaries? Yes
Installation about to begin with following settings: Continue.

After that wait untill sdk will be installed.

Running system.

@/scratchbox/login

run following command from scratchbox

>sb-conf select DIABLO_ARMEL

Start Xephyr from other terminal using any user

@Xephyr :2 -host-cursor -screen 800x480x24 -dpi 96 -ac -extension Composite

In useinstalling manual there is -screen 800x480x16 parameter, but I've changed it into -screen 800x480x24, because my Xephyr crashed.

Now return to our scratchbox where we already logged on.

export display:

>export DISPLAY=:2

following command should start the Hildon Application Framework inside the Xephyr window:

>af-sb-init.sh start

Also you can install metapackage of Nokia EUSA licensed
binaries as it recommended after installing SDK:

>fakeroot apt-get install maemo-explicit

Happy Hacking !

for more information see useinstalling manual

Variable parameters count in #define

2009-03-20T07:48:00.000-07:00

There are two ways:
1.
#define MAKE_INT_ARRAY(name,size,values) int name [size]= { values }
#define _ ,

MAKE_INT_ARRAY (i1, 1, 1);
MAKE_INT_ARRAY (i2, 2, 1 _ 2);
MAKE_INT_ARRAY (i8, 8, 1 _ 2 _ 3 _ 4 _ 5 _ 6 _ 7 _ 8);

#undef _

2. Using Boost.Preprocessor

#define MAKE_INT_ARRAY(name, values) \
int name[BOOST_PP_SEQ_SIZE(values)] = { BOOST_PP_SEQ_ENUM(values) }

MAKE_INT_ARRAY (i1, (1));
MAKE_INT_ARRAY (i2, (1)(2));
MAKE_INT_ARRAY (i8, (1)(2)(3)(4)(5)(6)(7)(8));

But you should remember, do not use macros if you can avoid it. It is a bad style of programming.

Running squish tests on Xephyr X server (Fedora 9)

2009-03-20T03:18:00.000-07:00

Squish is test tool for Qt applications. Sometimes when you need run tests and you have only one machine for it - your workstation,- it is very boring. So I decided to do it on other display. But I've had a problem with squish, when I've been trying to run squish tests on another display.
There is what I did:

Started another display:

Ctrl+Alt+F1
login
# xinit -- :1

switch to display:

on my Fedora 9 it is Ctrl+Alt+F8 or some another 'F' bigest than 7
and then run squish tests as on usual 0 display, but there was a problem. When I switched to 0 display squish was waiting "for me" and did not do it's job.

Solution is using Xephyr X server.

Installing:

# sudo yum install Xephyr

Running:

# Xephyr :3 -screen 1280x920 -ac

:3 - third virtual display
-screen 1280x920 - display resolution
-ac disable access control restrictions. Without this option squish could not access to my virtual display:

No protocol specified
_squish: cannot connect to X server :3

Accessing:

open another terminal and export display there
# export DISPLAY=:3
run squish from this terminal.

You can run terminal instead squish and after that you can run anything what you need for your comfortable work (metacity, gnome-panel, whatever you want)

Also you can export display to Xephyr on any host
# export DISPLAY=0.0.0.0:3
Do not forget to run # xhost + on remote host

Now when my tests are running on Xephyr I have a time to write this blog )