OS X launchd.plist

Question

这是我的plist文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC -//Apple Computer//DTD PLIST 1.0//EN http://www.apple.com/DTDs/PropertyList-1.0.dtd >
<plist version="1.0">
<dict>
  <key>Label</key>
  <string>com.homebrew.autoupdate</string>
  <key>ProgramArguments</key>
  <array>
    <string>/usr/local/bin/brew_up</string>
  </array>
  <key>StartInterval</key>
  <integer>86400</integer>
  <key>StandardErrorPath</key>
  <string>/usr/local/var/log/brew.log</string>
  <key>StandardOutPath</key>
  <string>/usr/local/var/log/brew.log</string>
</dict>
</plist>

/usr/local/bin/brew_up只是一个调用brew update、brew upgrade等的脚本

#!/bin/sh
echo `date`: Start updating brew
/usr/local/bin/brew update && /usr/local/bin/brew upgrade && /usr/local/bin/brew cleanup
echo `date`: Finish updating brew

然后我通过launchctl load ~/Library/LaunchAgents/homebrew.autoupdate.plist加载了那个文件

然后我试了试launchctl start com.homebrew.autoupdate，它也工作得很好。

但问题是，它不会像我预期的那样每24小时启动一次。其实现在已经过去了四十八个多小时了，还是一次都没有启动。这里我漏掉了什么？

然后我将StartInterval更改为StartCalendarInterval

  <key>StartCalendarInterval</key>
  <dict>
    <key>Hour</key>
    <integer>21</integer>
  </dict>

然后它被无限期地启动，日志文件如下：

Thu Aug 7 21:17:20 CST 2014: Finish updating brew
Thu Aug 7 21:17:20 CST 2014: Start updating brew
Already up-to-date.
Thu Aug 7 21:18:14 CST 2014: Finish updating brew
Thu Aug 7 21:18:14 CST 2014: Start updating brew
Already up-to-date.
Thu Aug 7 21:19:39 CST 2014: Finish updating brew
Thu Aug 7 21:19:39 CST 2014: Start updating brew
Already up-to-date.
Thu Aug 7 21:22:28 CST 2014: Finish updating brew
Thu Aug 7 21:22:28 CST 2014: Start updating brew
Already up-to-date.
Thu Aug 7 21:24:46 CST 2014: Finish updating brew

更新:我认为这意味着crontab中的* 21 * * *，所以如果它是

      <key>StartCalendarInterval</key>
      <dict>
        <key>Hour</key>
        <integer>21</integer>
        <key>Minute</key>
        <integer>0</integer>
      </dict>

应该能行得通。

但是，StartInterval到底出了什么问题？

顺便说一句，我刚刚试着写了一个简单的演示来测试StartInterval，它完全起作用了！

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC -//Apple Computer//DTD PLIST 1.0//EN http://www.apple.com/DTDs/PropertyList-1.0.dtd >
<plist version="1.0">
<dict>
  <key>Label</key>
  <string>com.test.touch</string>
  <key>ProgramArguments</key>
  <array>
    <string>touch</string>
    <string>/tmp/touched.txt</string>
  </array>
  <key>StartInterval</key>
  <integer>60</integer>
</dict>
</plist>

Answer 1

对于计划的定时作业，应使用key StartCalendarInterval (Reference)

<key>StartCalendarInterval</key>
<dict>
    <key>Hour</key>
    <integer>11</integer>
</dict>

Answer 2

在launchd开发人员文档中的某处有一条警告，即按需服务需要保留一段最短的时间。(类似于10秒IIRC。)否则，launched会认为它们无法正常启动，并会尝试重新启动它们。

尝试将sleep 30添加到您的shell脚本中，看看这是否解决了不断重启的问题。