FreeBSD 之下 GDM 忽略 ~/.xsession 問題

最近在 FreeBSD 之下建置桌面環境，一直為 GDM 這個 desktop manager 苦惱。因為執行時他完全不理會 ~/.xsession，致使我必須手動執行 gcin 才可以使用中文輸入法。



早上花了 3 個小時研究，也到 /usr/local/etc/gdm/ 下面讀了 GDM 的相關 scripts，其中最為重要的就是 Xsession 這支程式。在 Xsession 之中，有一段是這麼寫的：

if [ "x$command" = "xcustom" ] ; then
  if [ -x "$HOME/.xsession" ]; then
    command="$HOME/.xsession"
  else
    echo "$0: Cannot find ~/.xsession will try the default session"
    command="default"
  fi
fi

乍看之下，GDM 會有條件執行 ~/.xsession，只要 $command 的內容是 "custom" 即可，於是一開始便朝這方向嘗試。不過 GDM 是在開機時由 FreeBSD 自動喚起（/etc/rc.conf 設定 gdm_enable="YES"），不曉得要如何將 "custom" 做為 Xsession 的參數傳遞進去。思考幾分鐘後決定放棄，改朝其他方向嘗試。

皇天不負苦心人，後來讓我在 FreeBSD mailing list 裡撈到一篇有關 GDM 設定的討論文章（http://lists.freebsd.org/pipermail/freebsd-questions/2006-April/119887.html），其內容摘錄如下：

So... I had found a few HowTo's on customizing GDM on the web. All said
similar things but nothing worked for me. What they said to do *was*
important, and in fact was 99% of the work. So here's what I did to get
GDM to run my .xsession file (last step did the trick):

1) install /x11/gdm
2) make sure you have an ~/.xsession file (setup however you like)
3) make sure you have #!/bin/sh as first line
4) make sure ~/.xsession is executable
5) create a file /usr/X11R6/etc/gdm/Sessions/MySession.desktop
(replace MySession with whatever name you like)
6) Give it the following contents
[Desktop Entry]
Encoding=UTF-8
Name=XSession
Comment=This session will run your ~/.xsession
Exec=~/.xsession
Icon=
Type=Application
(feel free to change name and comment to liking)
7) Edit your /usr/X11R6/etc/gdm/gdm.conf. Search for
SessionDesktopDir. In my conf file it was commented out (plus a typo).
So I created a new SessionDesktopDir and pointed it where I placed my
*.desktop file. Such as SessionDesktopDir=/usr/X11R6/etc/gdm/Sessions/.

That's it. My new session is now visible, and runs my .xsession
seemingly just as XDM had.

There's plenty of eye candy for GDM. I'm sure there is a port in ports
that will install some, but haven't looked. I simply copied a dir of
themes from a gentoo box.

重點其實是在 GDM 的 session 設定檔中（/usr/X11R6/etc/gdm/Sessions/*.desktop；在我的系統上是 /usr/local/share/xsessions/*.desktop），將 *.desktop 設定檔之中的 exec 鍵值改為 ~/.xsession 則此問題馬上迎刃而解。

真是可喜可賀。