Slash vs Manual Override

An offline subnet calculator for CCNA, Network+, and anyone who works with IP networks day to day. This is the original Slash - the calculator I built for myself so I could check subnetting in seconds instead of doing the math by hand every time. Type it in or paste it from wherever you copied it; Slash works out the rest, all on-device. Features: - Type or paste a CIDR (192.168.1.0/24), a bare address, or a subnet mask - Slash fills in the rest - Network address, first and last host, broadcast, and where the next subnet starts - Paste straight from Cisco IOS, ifconfig, or ipconfig output and it pulls the address and mask out for you - Tap any value to copy it - "More details" opens the wildcard mask, usable host count, and a bit-by-bit binary view - Hand it just a mask and get the CIDR prefix, wildcard, and the hex netmask (the ifconfig / route-table style) - /31 point-to-point (RFC 3021) and /32 handled the way they actually behave - IPv6 when you need it, light or dark, Recents, optional haptics - Fully offline. No accounts, ads, tracking, or subscriptions. Free. - Shamelessly vibe coded using Fable 5; the subnet math lives in its own package and is hand-verified for accuracy About me: I'm a working network engineer and active CCNA, currently living in the beautifully warm state of Arizona. Questions, feedback, or a result you can't explain? Email me any time - I'm responsive, and my email actually works. Privacy: https://tylerdix.com/slash/#privacy Slash is an independent tool, not affiliated with, endorsed by, or sponsored by Cisco Systems, Inc. or CompTIA, Inc. CCNA and Network+ are trademarks of their respective owners.

A hands-on introduction to the command line and SQL. You type the commands. No videos, no syntax tables to memorise. Each lesson hands you real material and a question you have to answer yourself, and you answer it by typing real commands. Get one wrong and you get a real error message, worded the way a real terminal words it. WHAT YOU LEARN · Filesystem: pwd, ls (with -a / -R), cd, cat, find · Text: head, tail (with -n +N / -n -N), wc, sort, uniq · Search: grep, with -i / -R / -F / -n and regular expressions · Compare and verify: diff (normal and -u unified format), sha256sum · SQL: SELECT, WHERE, ORDER BY, LIKE, JOIN, GROUP BY / COUNT / HAVING · One habit running through all of it: any conclusion should be something a stranger can re-run command by command HOW THE COURSE IS BUILT Eleven lessons, each with one answer you have to find for yourself. The material is a virtual filesystem and a real SQLite database. Commands run in a sandbox and never touch your device; the database is read-only, so no query you write can break anything. Most puzzles accept more than one solution: the way you already know works too. ALSO INCLUDED · Offline syntax manual and table-schema reference, always one tap away · Practice mode (with the full course): the terminal and database with no lesson flow, just type · Command and flag completion, Tab completion, history recall — built for touch · Three colour schemes, text size, reduced motion, haptics toggle · Runs entirely offline. No network, no data collected, no account, no ads ABOUT THE STORY A fictional storyline ties the eleven lessons together: you are reviewing an obsolete course package scheduled for deletion, and you use each command you have just learned to check the material against itself. The story is the premise for the exercises, not a substitute for them — every conclusion is still one you type out yourself. The prologue and the first three lessons — the whole command-line half — are free. Lessons 4 to the finale (the SQL half) and practice mode are one purchase: no subscription, no ads, no account.