The Linux Korean Input Experience

Environment

• Fedora 42 (Kinoite)
• KDE Plasma 6.4.3
• fcitx5 && fcitx5-hangul

Korean input in Steam and Steam games

• Cause: X11 apps need XIM for Korean input
• Fix: set the XMODIFIERS environment variable

YOUR_INPUT_METHOD=fcitx # change if using ibus or other IMEs

echo "XMODIFIERS=@im=$YOUR_INPUT_METHOD" | sudo tee -a /etc/environment

Log out and back in. If you see:

echo $XMODIFIERS $LANG
> @im=fcitx ko_KR.UTF-8

Reference: https://wiki.archlinux.org/title/Fcitx5#XIM

Korean input in flatpak apps

• Cause: QT apps require QT_IM_MODULE to enable Korean input
• Fix: set QT_IM_MODULE in /etc/environment

YOUR_INPUT_METHOD=fcitx # change if using ibus or other IMEs

echo "QT_IM_MODULE=$YOUR_INPUT_METHOD" | sudo tee -a /etc/environment

Log out and back in. If you see:

echo $QT_IM_MODULE
> fcitx

Reference: https://krita-artists.org/t/i-just-cant-use-ime-to-type-texts-on-linux/113246/2

No Korean input in distrobox-installed apps

• Cause: distrobox containers cannot access host IME packages (ibus, fcitx...)
• Fix: install IME packages inside the container

$ distrobox enter <YOUR-CONTAINER-NAME>
$ sudo dnf install fcitx5 fcitx5-hangul

Prevent ㄱㅅ → ㄳ, ㄱㄱ → ㄲ

• Cause: libhangul has not been released since 2011, so there is no API to toggle this setting
• Fix: apply your desired settings and build libhangul manually

Environment setup

git clone https://github.com/libhangul/libhangul
cd libhangul

sudo dnf install gcc make gettext gettext-devel libtool libtoolize aclocal autoconf expat-devel

Apply settings

• ㄱㄱ → ㄲ disabled: in latest git builds this is disabled by default
• ㄱㅅ → ㄳ disabled: set HANGUL_IC_OPTION_NON_CHOSEONG_COMBI default to false

diff --git a/hangul/hangulinputcontext.c b/hangul/hangulinputcontext.c
index ee43f5e..bdd3ad0 100644
--- a/hangul/hangulinputcontext.c
+++ b/hangul/hangulinputcontext.c
@@ -1511,7 +1511,7 @@ hangul_ic_new(const char* keyboard)
 
     hic->option_auto_reorder = false;
     hic->option_combi_on_double_stroke = false;
-    hic->option_non_choseong_combi = true;
+    hic->option_non_choseong_combi = false;
 
     hangul_ic_set_output_mode(hic, HANGUL_OUTPUT_SYLLABLE);
     hangul_ic_select_keyboard(hic, keyboard);

Apply the patch in the cloned repository.

Build and install

make -j $(nproc)
sudo make install
sudo ldconfig

If you see:

ldconfig -p | grep libhangul
        libhangul.so.1 (libc6,x86-64) => /usr/local/lib/libhangul.so.1
        libhangul.so.1 (libc6,x86-64) => /lib64/libhangul.so.1
        libhangul.so (libc6,x86-64) => /usr/local/lib/libhangul.so

If libhangul is installed somewhere like /usr/local/lib and ldconfig doesn't pick it up, add the path and rerun:

echo '/usr/local/lib' | sudo tee -a /etc/ld.so.conf.d/usr_local_lib.conf
sudo ldconfig

After confirming libhangul.so is in ldconfig, log out and back in so the changes apply to fcitx5-hangul.