I've been discvering some long lasting linux techs to help automate my daily work. I found cron
to be very powerful if I can use it to check the updates of some packages I have on my system.
For example, I want to update my Homebrew
everyday at 11pm. What I did is, with sudo crontab -u user -e
, I opened up crontab
in Vim. And I put following commands into it, to make updates for homebrew
and send me an email.
Here's the code:
[email protected]
* 23 * * * brew update
and I save it to wait for magic happens. Instead of excuting this command, in the email I recieved, it says /bin/sh: brew : command not found
But when I type /bin/sh
in terminal to open sh
and type in brew update
it will update the Homebrew
。
What did I do wrong with my crontab
configuration?
Any help will be appreciated!
A cronjob is a good option, but I didn't want it to happen automatically. I found a script that will notify you if a new version of a formula installed on your Mac is available.
I extended the script to not show pinned formulae in the notifier.
I decided to use a launchd-agent for the cronjb, because this also runs if Mac is started later. Cron-jobs just run if your mac is already on at that time.
For a comparison of cronjob vs launchd, I recommend reading this.
Here's my configuration which runs every day at 10am and 3pm. The script, called by the agent, is located at /usr/local/bin/homebrew-update-notifier
.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>EnableGlobbing</key>
<false/>
<key>Label</key>
<string>homebrew.simonsimcity.update-notifier</string>
<key>ProgramArguments</key>
<array>
<string>/bin/bash</string>
<string>/usr/local/bin/homebrew-update-notifier</string>
</array>
<key>RunAtLoad</key>
<true/>
<key>StandardErrorPath</key>
<string>/tmp/homebrew.simonsimcity.update-notifier.err</string>
<key>StandardOutPath</key>
<string>/tmp/homebrew.simonsimcity.update-notifier.out</string>
<key>StartCalendarInterval</key>
<array>
<dict>
<key>Hour</key>
<integer>10</integer>
<key>Minute</key>
<integer>0</integer>
</dict>
<dict>
<key>Hour</key>
<integer>15</integer>
<key>Minute</key>
<integer>0</integer>
</dict>
</array>
</dict>
</plist>
You will now be notified if a new update is available. Call brew upgrade
if you feel outdated, or include it in the script.