ToolsOpsCron expression examples for Linux and Unix
Practical Unix/POSIX cron examples: every 5 minutes, hourly, weekdays, monthly jobs and more. Includes POSIX OR semantics and common pitfalls.
Guides for developers and sysadmins
Practical ToolsOps guides about cron, Linux permissions, CIDR subnetting and useful tools for developers and sysadmins.
CIDR subnetting guide for IPv4
Learn IPv4 CIDR and subnetting with /24, /30 and /32 examples, IP ranges, subnet masks and practical use cases.
Linux chmod permissions guide
Linux chmod permissions: 755, 644 and 777 modes, symbolic notation, safe examples and common mistakes when setting permissions.