Definite's Extractor

My findings on Life, Linux, Open Source, and so on.

[COPR] Why my patches are missing from custom build

Custom build script in COPR is a versatile. With a couple sed commands, you can modify Fedora SPEC files and port it to RHEL/CentOS Stream with a little effort.

However, when I was porting the keepassxc-2.7.X a few days ago, COPR keeps complaining xcb.patch is missing. While I myself does not need the patch for Wayland, I am curious why other packages are fine but not this one.

Eventually, it is because Patch0: xcb.patch was in conditional, like:

%if 0%{?el8}
Patch0: xcb.patch

The SRPM maker did not run under el8, thus Patch0 is not in SRPM.

Since my repo contains just EL8 and EL9 packages, I can simply make the conditional always say yes. So I put down following like in the script:

sed -i -e '/^%if 0%{[?]el8}/ s/0%{[?]el8}/1/' $PKG.spec

This solved the problem.


Oneliner to extract CentOS Stream package source in dist-git repo

-While investigating the sources of RHEL and Fedora packages, firstly I switch to corresponding branch, then do either rhpkg prep or fedpkg prep to extract source.

Recently, I am interested in CentOS Stream 9, and wish to investigate the source. However, I am too lazy to find the fedpkg or rhpkg equivalent for CentOS Stream, and found the following command useful:

/bin/spectool -g $(basename $PWD).spec; /bin/rpmbuild --nodeps --define "_sourcedir $PWD" --define "_builddir $PWD" --define "_buildrootdir $PWD" -bp $(basename $PWD).spec

Fedora Packaging: resolving /usr/bin/../bin/../lib/bfd-plugins/ wrong ELF class: ELFCLASS32

When I provide an update to barrier-2.4.0, I encountered:

/usr/bin/../bin/../lib/bfd-plugins/ wrong ELF class: ELFCLASS32

Barrier uses CMake to build. It called ar and ranlib during the build, however, wrong plugins was invoked and caused the above error.

While the above error can be avoided by adding option --plugin , however, CMake does not have an easy way to do that. Fortunately, gcc provides gcc-ar and gcc-ranlib wrappers that point to the correct plugins. So I inserted the commands that point to gcc-ar and gcc-ranlib in the section %prep with:

sed -i.use-gcc-ar -e '/include (CheckIncludeFiles)/ i set(CMAKE_AR "/usr/bin/gcc-ar")' CMakeLists.txt
sed -i.use-gcc-ranlib -e '/include (CheckIncludeFiles)/ i set(CMAKE_RANLIB "/usr/bin/gcc-ranlib")' CMakeLists.txt

The build worked.

How to get the active title of an X program

I have scripts that will utilise the SFDC case number, but why type it manually when the computer can do it?

Firstly, you need to have xdotool installed, for RHEL or CentOS Stream, it is in EPEL. I have tried xprop and xwininfo, but they do not accept search with WM_Class

Secondly, get the WM_Class of the X program, usually it is just the program name. If you are unsure, open that X program, then run xprog and click at the X program, then search WM_CLASS amongst the output.

Thirdly, for X program that has multiple tabs, make sure you activate the tab you want.

Now, to get the active title of firefox:

for i in $(xdotool search --onlyvisible --class firefox); do xdotool getwindowname $i; done

Two titles will be shown like:

The actual title

For me, I am only interest in the number which are in the beginning of the title, so my command is:

for i in $(xdotool search --onlyvisible --class firefox); do xdotool getwindowname $i; done | sed -rne '/^[0-9]+/ s/^([0-9]+).*$/\1/p'

Windows: Built-In Command That Tells Disk Usage

I was finding df alternative in Windows. The environment is Windows Server Core, thus I am looking for the built-in command that tell the disk usage.

The question, Free Space in a CMD shell pointed to correct direction. The following works for me:

wmic logical disk get deviceid,freespace,size

fsutil volume diskfree c:

Barrier/Synergy installation on EL8

I have packaged barrier and synergy a while ago. A user stated that he cannot install it because it misses dependency: avahi-compat-libdns_sd

For RHEL 8, it is in channel codeready-builder-for-rhel-8-x86_64-rpms

To enable it, runs
subscription-manager repos --enable codeready-builder-for-rhel-8-x86_64-rpms

For CentOS Stream 8, it is in repository powertools

To enable it, runs
sudo yum-config-manager --enablerepo powertools

Barrier (Synergy) with Wacom Intuos BT M

I am looking for a more ergonomic pointing device. Thus, I borrow my daughter’s Wacom Intuos BT M drawing tablet a try.

Fedora 33 Gnome seems to recognize it out of the box, and the gnome-control-center Wacom interface show it properly. With RHEL 8, it also works as a mouse, but for Gnome to see it, I needed to install the following:

yum -y install libwacom

I mainly use KDE, so I also install

yum -y install kcm_wacomtablet

Gnome did not have the UI to bind the tablet button to mouse button like Mouse button 4 (Scroll Up), nor does it handle key combo binding properly. For example, Ctrl-Win-Left is recognized as Primary-Super-Hyper-Left; KDE, however, does support Mouse button 4~7 so I bind inner left tablet button as button 5 and inner right tablet button as button 4.

I use barrier, a keyboard/mouse sharing utility intensively. So I would also like to see how barrier handles Wacom. Unfortunately, with absolute position mode (the default), the pointer insisted it needed to be in the left edge of the client, I need to use barrier switchInDirection keyboard short keyboard to get away.

I also tried related position mode which make the tablet work more like a giant touchpad. It kinda of work, as the pointer in client act normally. However, that mode is very unpleasant to use, as I need to fully away the distant between stylus and tablet. Basically:

State 1: Stylus touch tablet: Mouse Left button click
State 2: Stylus hover tablet: Mouse move
State 3: Stylus leave tablet: Mouse No action

Switching between State 2 and State 3 is required for related position to work, that is unpleasant.

I tried USB on server, and BT on client as well, but Intuos only support single connection, that is, you have to disconnect USB to use BT, so no single-button-toggle target computers. 😦

Verdict: I would not a recommended Wacom over Barrier/Synergy setup, unless You are OK with relative position mode.

Download Files Using Command in Windows Server Core 2016

I have a Windows Server 2016 in Core mode, i.e. most of the GUI programs are not available.


1. Set the SecurityProtocol. It is required for https:

[Net.ServicePointManager]::SecurityProtocol = 
  [Net.SecurityProtocolType]::Tls12 -bor `
  [Net.SecurityProtocolType]::Tls11 -bor `

2. The actual command, iwr, is an alias of Invoke-WebRequest :

iwr -outf filename



HOWTO: Configure Time (NTP) for Windows Server 2016 Using Command Line (cmd)

This is aimed to be complete steps for configuring the time service (NTP) for Windows Sever 2016. This is especially useful should you want to setup your own Active Directory Domain Controller (ADDC).

0. Networking Check

Ensure you can reach the NTP server. Assuming you are using :


1. Set the Time Zone

By default, windows just assume a time zone and show you the system clock. However, the default time zone is not necessary correct.

1.1. Check the Current Timezone

tzutil /g

1.2 (Optional) Query Available Time Zone

tzutil /l

1.3 (Optional) Set Time Zone

tzutil /s "E. Australia Standard Time"

2. Set the w32time service

2.1 Configure NTP Service

w32tm /config /manualpeerlist:"" /syncfromflags:manual /reliable:no /update

2.2 Confirm that NTP Configuration

List the peers

w32tm /query /peers
The result looks like:
#Peers 3
State: Active
Time Remaining: 123.4567890s
Mode: 1 (Symmetric Active)

List the time source

w32tm /query /source
The result looks like:

2.3 Resync

w32tm /resync
The result looks like:
Sending resync command to local computer
The command completed successfully.

2.4 Indicate that NTP service is now reliable

w32tm /config /reliable:yes /update

2.5 Confirm status

w32tm /query /status
The result should looks like:
Leap Indicator: 0(no warning)

This should be it.

Build in epel8 branch with fedpkg

This article assumes you have commit right to the package, but you don’t have the epel8 branch in

  1. PKG=<YourPackage>
  2. fedpkg clone $PKG # if you have not done this
  3. cd $PKG # if you have not done this
  4. git branch epel8
  5. # Make the branch work with epel8
  6. git commit
  7. git push –set-upstream origin epel8
  8. fedpkg build
  9. Go to bodhi and create -> New update