從crond到launchd ＊舊文出清＊

正油可爾必思 — Sun, 28 Jun 2009 15:48:39 +0000

新裝好的OSX86大白機，也許是因為系統提升到10.5.5之故，比起舊的藍白10.4 Server，log裡常常會有這樣的訊息：
May 8 23:30:00 openbunny com.apple.launchd[1] (0x10d430.cron[718]): Could not setup Mach task special port 9: (os/kern) no access May 8 23:35:01 openbunny com.apple.launchd[1] (0x10d230.cron[789]): Could not setup Mach task special port 9: (os/kern) no access May 8 23:35:01 openbunny com.apple.launchd[1] (0x10d430.cron[790]): Could not setup Mach task special port 9: (os/kern) no access May 8 23:40:00 openbunny com.apple.launchd[1] (0x10d230.cron[868]): Could not setup Mach task special port 9: (os/kern) no access May 8 23:40:00 openbunny com.apple.launchd[1] (0x10d430.cron[869]): Could not setup Mach task special port 9: (os/kern) no access May 8 23:45:00 openbunny com.apple.launchd[1] (0x10d230.cron[939]): Could not setup Mach task special port 9: (os/kern) no access
紀錄的時間還滿有規律性的。cron job的執行並沒有異常，但是每次執行都會噴這樣一行，實在有點煩。根據這篇，這是crond噴出來的沒錯，只是原因不明。唯一的解法就是不要用crond來跑cron job，改用從10.4起Apple推獎的launchd來跑。
原本有在跑的3個cron job，在/etc/crontab裡也就是3行：
*/5 * * * * root /opt/local/bin/mrtg /var/www/mrtg/cfg/mrtg.cfg --logging /var/log/mrtg.log */5 * * * * root scp /var/www/mrtg/192.168.10.100_2-day.png channinggao@solomini:~/Pictures/ */2 * * * * root /usr/local/bin/top.sh
若是要移轉到lauchd的架構，則是要把每個job轉換成一個對應的plist檔。比方說mrtg的cron job就會變這樣：
$ cat /Library/LaunchDaemons/com.channinggao.mrtg.plist





	Label

	com.channinggao.mrtg

	ProgramArguments

	

		env

		LANG=C

		/opt/local/bin/mrtg

		/var/www/mrtg/cfg/mrtg.cfg

		--logging

		/var/log/mrtg.log

	

	RunAtLoad

	StartInterval

	300

	UserName

	root

其實內容很容易懂，不過寫起來真的是囉哩巴唆；萬一弄錯一個符號或是語法有誤，launchd就會狂噴錯誤訊息：



May  8 23:59:12 openbunny com.apple.launchd[1] (com.channinggao.mrtg): Throttling respawn: Will start in 8 seconds

May  8 23:59:17 openbunny com.apple.launchd[1] (com.channinggao.mrtg): Throttling respawn: Will start in 3 seconds

May  8 23:59:22 openbunny com.apple.launchd[1] (com.channinggao.mrtg): Throttling respawn: Will start in 8 seconds

May  8 23:59:27 openbunny com.apple.launchd[1] (com.channinggao.mrtg): Throttling respawn: Will start in 3 seconds

May  8 23:59:32 openbunny com.apple.launchd[1] (com.channinggao.mrtg): Throttling respawn: Will start in 8 seconds

幸好有人寫了Lingo這個好用的小工具，只要填一填、勾一勾就可以輕鬆搞定了。話雖如此，我之前漏掉了UserName這個必須在Expert Mode手動建立的key值，還是讓我卡關了一個小時。可惜的是Lingo只能產生plist檔，不會教launch重新載入更新的plist設定。如果不想在改好plist後登出登入或重開機，可以透過lauchctl這個指令：



$ sudo launchctl unload com.channinggao.mrtg.plist

$ sudo launchctl load com.channinggao.mrtg.plist

$ sudo launchctl start com.channinggao.mrtg

跑不動的script

正油可爾必思 — Sun, 31 May 2009 11:55:22 +0000

最近常常發現用vi編輯的script，在執行時會出現：
-bash: ./autoMount.sh: /bin/sh^M: bad interpreter: No such file or directory
重點就是在後面多出來的^M。看來是vi不知怎搞的把預設的斷行字元弄成MSDOS了。要修正這種檔案，可以在vi裡下：
:%s/^M//g
但是這裡的^M不能是直接打出來的，得按Ctrl-v、Ctrl-m才行哦。

至於徹底的解法則是在家目錄下的.vimrc加上：
set ff=unix

=.= 街喵人生 » OSX

從crond到launchd ＊舊文出清＊

跑不動的script