crontab 路径和用户 [英] crontab PATH and USER

问题描述

我是使用 cron 和 crontab 调度任务的新手.我正在尝试安排任务的执行，就像我已登录、打开终端并自己执行一样.

I am new to scheduling tasks with cron and crontab. I am trying to schedule execution of a task as if I had logged on, opened a terminal, and executed it myself.

但是，我安排了一个任务来帮助我观察计划任务正在执行的 $USER 和 $PATH，这就是我发现的:

However, I scheduled a task to help me observe what $USER and $PATH a scheduled task is executing with, and this is what I found:

$ crontab -l
41 11 * * * echo "USER: $USER" > ~/Desktop/cron_env.log; echo "PATH: $PATH" >> ~/Desktop/cron_env.log
$ cat ~/Desktop/cron_env.log
USER:
PATH: /usr/bin:/bin

似乎没有设置 $USER，而 $PATH 是非常基本的和/或默认的.相反，这是我打开终端(登录)并回显相同信息时看到的:

It appears as though $USER is not set, and $PATH is something very basic and/or default. On the contrary, this is what I see when I open a terminal (logged in) and echo this same information:

USER: aschirma
PATH: /usr/lib/jvm/java-6-sun/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/pkg/icetools/bin:/pkg/hwtools/bin:/pkg/netscape/bin:/pkg/gnu/bin

我需要做什么才能让我的 crontab 任务按照我想要的方式运行?

What do I need to do to make my crontab tasks run the way I want?

推荐答案

根据man 5 crontab"，您可以在您的 crontab 中设置环境变量，将它们写在您的 cron 行之前.

According to "man 5 crontab" you can set environment variables in your crontab, by writing them before your cron lines.

还有一个 crontab 的例子，所以你只需要复制/粘贴它:

There is also an example of a crontab so you just have to copy/paste it :

$ man 5 crontab | grep -C5 PATH | tail 
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# m h dom mon dow usercommand
17 * * * *  root  cd / && run-parts --report /etc/cron.hourly
25 6 * * *  root  test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )
47 6 * * 7  root  test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )

因此您可以根据需要调整 PATH 或任何环境变量.但是这个例子对于典型案例来说似乎已经足够了.

So you can adjust your PATH or any environment variable to whatever you want. But this example seems enough for typical cases.

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