Qt: "cannot find -lGL" when linking, Fedora

When linking q project in qt on fedora system i saw the error "cannot find -lGL" , and after investigation i found that the IDE is searching for libGL.so while my library name on the system is called libGL.so.1 , so i just created a soft link  with .so ln -s /usr/lib/libGL.so.1 /usr/lib/libGL.so and then everything worked fine.

Makefile:4: *** missing separator. Stop. [solution]

When i tried to compile a program using a Makefile, i had the following error  

Makefile:4: *** missing separator.  Stop.

  after googling the error i found that `make` does not accept whitespaces and unlike DOS, it is expecting a tab in the beginning of each line.

so to solution is to replace the whitespaces ( in this case in the 4th line) with a tab.

reference: http://www.delorie.com/djgpp/v2faq/faq22_17.html

After Update Firefox is not working; /usr/lib64/firefox/firefox: symbol lookup error: /usr/lib64/xulrunner/libxul.so: undefined symbol: PR_SetCurrentThreadName [solution]

When i tried to run firefox after update on my fedora 17 machine,  when i was trying to run it nothing has appeared. also i tried to run it on terminal to find out what error is happening i got

/usr/lib64/firefox/firefox: symbol lookup error: /usr/lib64/xulrunner/libxul.so: undefined symbol: PR_SetCurrentThreadName

a quick search over the internet brought to me an easy solution since this problem seems to be popular, the solution was to update a package called nspr

#yum update nspr

reference : https://bugzilla.redhat.com/show_bug.cgi?id=865941

Fedora :: error: db4 error(-30974) from dbenv->failchk: DB_RUNRECOVERY

While I'm trying to install a program using yum, yum was locked by another process then i had to freed it by sending it SIGKILL, and after that i passed my program to yum to install it then ... OPS !! yum is displaying a fatal error 

"error: db4 error(-30974) from dbenv->failchk: DB_RUNRECOVERY: Fatal error, run database recovery
error: cannot open Packages index using db4 - (-30974)
error: cannot open Packages database in /var/lib/rpm
CRITICAL:yum.main:
Error: rpmdb open failed"

tried too many solution like cleaning up the yum's DB and it didnt solve it and in the end i fixed the problem by cleaning the RPM's DB and rebuild it again.

$ sudo rm -rf /var/lib/__db*

$ sudo rpm --rebuilddb

$ reboot # i had to reboot to solve it as well.

/boot/syslinux/ldlinux.sys: no match for target

If you are getting the error

"/boot/syslinux/ldlinux.sys: no match for target
syslinux: warning: unable to move ldlinux.sys"

then you are probably trying to install the syslinux boot loader to solve it make sure

1) your drive ( partition)  which you are trying to install syslinux on is either FAT16 or FAT32 otherwise syslinux will fail to start.

2) you have already created the file in your storage. using

$ mkdir -p /boot/syslinux/

then normally execute the syslinux installation command

$ syslinux -f -d /boot/syslinux /dev/sdb1

Installing Skype on Fedora 16 x64 machine using Autoplus (Error: Protected multilib versions)

Presumption

you are getting "Error: Protected multilib versions" when trying to install Skype using Autoplus on x64 system.

Solution

"Error: Protected multilib versions: glibc-2.14.90-24.fc16.6.i686 != glibc-2.14.90-14.x86_64"

This error seems to be occurred because skype is x32 bit executable but the system is x64, the "file" output says

/usr/bin/skype: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.9, stripped

To solve this problem you have to install the glibc but the x32 bit, to do that, simple execute

$ sudo yum install  glibc-2.14.90-24.fc16.6.i686

If you have more "Protected multilib versions" just install thier x32 version then run autoplus and install Skype.

How to customize fedora 16 and make it functional

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Presumption

Installed distro is Fedora 16 with Gnome 3 desktop environment.

Adding close and minimize buttons to windows

$ yum install gconf-editor

run it after installation by clicking on ALT+F2 then write “gconf-editor ” and hit enter.

in the Configuration Editor navigate to desktop --> gnome --> shell --> windows

Find “button_layout” and click on it and change it to ":minimize,maximize,close" .

logoff and logon again OR ALT+F2 then write “r ” and hit enter.

Show desktop icons and right clicks

 $ yum install dconf-editor 

Go to org --> gnome --> desktop --> background and check the box to show desktop icons. 

While this brings back desktop icons, and enables right clicking on the desktop, it makes the computer, home, trash icons visible. These are usually hidden with Ubuntu. To make them hidden again, but still allowing icons on the desktop, go to nautilus --> desktop, and uncheck the boxes for the icons you want hidden. 

Taskbar & dock

$ yum install docky # if you like dock-like taskbar

$ yum install tint2 # if you like classical taskbar

$ yum install gnome-panel # if you like the gnome original panel

to run and test them, ALT+F2 then write the name of program you want to run.

Personally i would recommend the gnome-panel for stability reasons, to add it to every system start up, ALT+F2 then write “gnome-session-properties” and hit enter, put name, lets say “gnome panel”, command “gnome-panel --replace”, and comment “ start up gnome-panel” then click add.

Hide all windows

usually, fedora user was hiding all menu by clicking ALT+CTRL+D, i like windows way to hide them (because it is uses less keys) which is WinKey (Or Super)+D.

To make it functional, hit WinKey and write "keyboard" --> "shortcuts" -->navigation --> "hide all normal windows " then set the shortcut you like.

Customizing the icons, fonts & theme

$ yum install gnome-tweak-tool

Then run it by hitting ALT+F2 then write “gnome-tweak-tool ” and having happy customization!

I like default xfce icons which is rodent icon set . I didn't find away to install it independently so i went to install the xfce desktop environment.

$ yum install xfce4-icon-theme

ALT+F2 then write “r ” and hit enter, after making any changes.

Fonts

the fonts "Tahoma" and "Calibri" are pretty enough with many languages support , they can be installed from windows directory. 

Gnome shell extensions

to install most of gnome extensions 

$ yum install gnome-shell-extension* 

the gnome-tweak-tool can be used for extensions customization.

Codeblocks

$ yum install codeblocks # for codeblocks

$ yum install codeblocks-contrib #for most plugins 

System monitoring gadget

"gkrellm" is nice and does the job 

$ yum install gkrellm 

To download transparent theme

http://gnome-look.org/content/show.php/Transparent+Gkrellm?content=33783

To install the theme

Untar it on /home/<user_name>/.gkrellm2/themes