Practical guides to cron, Unix time, file permissions and the other everyday details that trip developers up.
5 articles
SSH refuses to use a private key that other people could read. Here is exactly which permissions it wants, and how to set them on Linux, macOS, Windows and WSL.
What rwx really means, how numbers like 755 and 644 are built, when to reach for chown instead of chmod, and how to fix permission denied without resorting to 777.
A date that lands in 1970, or tens of thousands of years from now, is almost always a unit mix up. Here is how to spot seconds and milliseconds at a glance and convert safely in any language.
Cron has no idea where you are. It follows the server's clock, and twice a year that clock does something strange. Here is how to control both.
Your crontab looks right and the job still never runs. These are the ten causes behind almost every silent cron failure, in the order worth checking them.