ToolDock Blog https://tooldock.dev/blog Practical guides to everyday developer tasks, each with a free tool to try. en-us CIDR Notation Explained: What /24, /16 and /32 Mean https://tooldock.dev/blog/cidr-notation-explained https://tooldock.dev/blog/cidr-notation-explained Learn how CIDR notation like 192.168.1.0/24 works, how to work out netmasks and usable hosts, which ranges are private, and how to split a network into subnets. Sat, 03 Oct 2026 00:00:00 GMT Semver Ranges: Caret (^) vs Tilde (~) in package.json https://tooldock.dev/blog/semver-caret-vs-tilde https://tooldock.dev/blog/semver-caret-vs-tilde What ^1.2.3 and ~1.2.3 actually allow in package.json, why 0.x versions behave differently, and how semver decides that 1.10.0 is newer than 1.9.0. Fri, 25 Sep 2026 00:00:00 GMT Unix Timestamps: Convert Epoch Time to a Date (and Avoid the Usual Bugs) https://tooldock.dev/blog/unix-timestamp-to-date https://tooldock.dev/blog/unix-timestamp-to-date What a Unix timestamp is, how to tell seconds from milliseconds, how to convert epoch time in JavaScript, Python, SQL and the shell, and time zone bugs to avoid. Fri, 18 Sep 2026 00:00:00 GMT Cron Syntax Explained, with 15 Ready-to-Use Examples https://tooldock.dev/blog/cron-expression-syntax-explained https://tooldock.dev/blog/cron-expression-syntax-explained Learn the five fields of a cron expression and the special characters *, /, - and comma, then copy tested schedules for crontab, Kubernetes and GitHub Actions. Fri, 11 Sep 2026 00:00:00 GMT UUID v1 vs v4 vs v5 vs v7: Which Version Should You Use? https://tooldock.dev/blog/uuid-versions-explained https://tooldock.dev/blog/uuid-versions-explained What each UUID version is built from, why v4 is the safe default, when name-based v5 helps, and why time-ordered v7 is becoming the choice for database keys. Fri, 04 Sep 2026 00:00:00 GMT How to Decode a JWT (and What Each Part Means) https://tooldock.dev/blog/how-to-decode-a-jwt https://tooldock.dev/blog/how-to-decode-a-jwt Learn how to decode a JSON Web Token by hand or in your browser, read its header, payload and claims like exp and iat, and why decoding is not verifying. Fri, 28 Aug 2026 00:00:00 GMT chmod Explained: What 755, 644 and 600 Actually Mean https://tooldock.dev/blog/chmod-permissions-explained https://tooldock.dev/blog/chmod-permissions-explained Read Unix file permissions in octal and symbolic form, see what chmod 755, 644, 600 and 777 allow, and pick safe modes for scripts, web files and SSH keys. Fri, 21 Aug 2026 00:00:00 GMT What Is Base64 Encoding, and When Should You Use It? https://tooldock.dev/blog/what-is-base64-encoding https://tooldock.dev/blog/what-is-base64-encoding How Base64 turns bytes into text, why encoded data grows by a third, how Base64Url differs, and why Base64 is never a way to hide or secure data. Wed, 12 Aug 2026 00:00:00 GMT