为什么在此Cron作业中带波浪号的有效路径没有扩展？ [英] Why is a valid path with a tilde not expanding in this cron job?

问题描述

我的crontab中有以下几行：

I had the following lines in my crontab:

PY=/home/schemelab/install/miniconda/bin/python
ST=~/prg/surgetrader

# SURGE TRADER

00  * * * * cd $ST/src/ ; $PY download.py; $PY scan.py --buy 1

当它运行我的电子邮件中的错误消息是：

And when it ran the error message in my email was:

X-Cron-Env: <GT=~/prg/gridtrader>
X-Cron-Env: <AGT=~/prg/adsactly-gridtrader>
X-Cron-Env: <PY=/home/schemelab/install/miniconda/bin/python>
X-Cron-Env: <ST=~/prg/surgetrader>
X-Cron-Env: <SHELL=/bin/sh>
X-Cron-Env: <HOME=/home/schemelab>
X-Cron-Env: <PATH=/usr/bin:/bin>
X-Cron-Env: <LOGNAME=schemelab>
Date: Sun, 30 Jul 2017 09:50:02 -0400 (EDT)

/bin/sh: 1: cd: can't cd to ~/prg/surgetrader/src/
/home/schemelab/install/miniconda/bin/python: can't open file 'takeprofit.py': [Errno 2] No such file or directory

但是，路径确实存在。我认为代字号没有得到扩展。

However, the path certainly does exist. I think that the tilde is not being expanded or something.

推荐答案

波浪符〜分辨率是一项bash功能。但是，您的cronjob不是通过Bash执行的（如果需要，可以显式执行）。但是，您可以使用 $ HOME 独立于外壳程序来引用用户主目录。

Tilde ~ resolution is a bash feature. However your cronjob is not executed through Bash (You could do it explicitly if you want). However you can use $HOME to refer to the user home independently of the shell.

请参考 Bash参考手册以获取更多信息。

Refer to Bash reference manual for more info.

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