This page aims to explain how to setup a chinese input on a french system. On the 3 following operating systems, the chinese input can be made under several methods (pinyin, ...) and the switch between normal and chinese modes is made by hitting Ctrl-Space. Some network softwares crash if you send a message in chinese mode, so you have to back to normal mode before send the chinese text.
You can add some languages in the Configuration Panel. Then on the top-right of the global menu bar (near the clock), you can switch between these languages by selecting the matching flag.
Recent OS have their multilanguage support, including the MIME chinese input. However you may use a specific software such as NJ-Star or C-Star to get more functions (Chinese WordArt, Chinese DOS, Chinese dictionaries ...).
QT assumes the input context (test on QT 3.3 + KDE 3.4). In order to get the french and the chinese input at once, I start run the KDE session in Chinese mode (selected from Session Login Panel). This may change the selected country (to China), the selected language (to simplified Chinese) and the GDM language. Once logged, I changed back the country to France, and I added and placed at first the French language (without removing the Chinese language). The parameters of my system are now LANG=zh_CN.UTF-8 and GDM_LANG=zh_CN.UTF-8, but the country and language in KDE board is french. Type env | grep LANG to get these parameters. As in the case of Windows, you may install a specific software to get additional functionalities. For instance, Chinput software and the unicon font library. Some softwares such as GNU Emacs may disable the Ctrl-Space to another functionality. You have to disable this function or replace the shortcut key to avoid losing the chinese input in this environment. For Emacs, the lisp command would be (global-set-key (kbd "M-SPC") 'set-mark-command). If you want to run a single application in a different language than the global selected language, you can type /usr/bin/env LANG=fr mysoftware & (fr for french, en for english and zh_CN for chinese).
Install the SCIM software with the following shell command:
apt-get install scim scim-bridge-agent scim-bridge-client-gtk scim-bridge-client-qt scim-chinese scim-gtk2-immodule scim-modules-table scim-pinyin scim-tables-zh xfonts-intl-chinese
When you are working in an environment (gedit, shell, ...), right-click and choose Input Method in the contextual menu. Select SCIM Input Method. If the option doesn't exist, you can also launch your application with the shell command:
export LC_CTYPE=zh_CN.UTF-8; mysoftware &