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The sips command on macOS shown as sips -s format jpeg star dot HEIC --out converted slash, with notes that it converts HEIC to JPG, PNG and TIFF, resizes with -Z 800, and batches a whole folder from the Terminal

The sips Command: Convert and Resize Images from the Mac Terminal

by Marcus Reeve
August 30, 2026July 19, 2026

Every Mac ships with sips — Scriptable Image Processing System — so there is nothing to install to convert, resize, or rotate an image from the Terminal. For a single photo, the Finder is honestly…

A crontab line 30 3 * * 1 broken into labeled fields (minute, hour, day, month, weekday) followed by the command, with notes that macOS cron needs Full Disk Access, runs with a minimal PATH, and is started on demand by launchd

How to Use crontab on macOS (and Why Cron Jobs Don’t Run)

by Marcus Reeve
August 28, 2026July 19, 2026

cron still works on macOS. The crontab command is built in — there is nothing to install — and it schedules jobs with the same five-field syntax you would use on Linux. The trouble Mac…

macOS terminal showing three rsync examples: rsync -av src/ backup/ to copy a folder, rsync -av --delete src/ backup/ to mirror it, and rsync -avz proj/ user@host:proj/ to sync over SSH, with a flag legend for -a archive, -v verbose, -z compress, -P progress and resume, and -n dry-run.

How to Use rsync on macOS: Examples and Common Flags

by Marcus Reeve
August 25, 2026July 19, 2026

rsync copies and syncs folders efficiently — it only transfers the parts that changed, which makes it ideal for backups and for keeping two machines in step. It’s built into macOS, so there’s nothing to…

macOS terminal showing ipconfig getifaddr en0 returning a local IP 192.168.1.42, with a table: any interface reliably via ipconfig getifaddr with route get default, public IP via curl api.ipify.org, and a note that the Linux ip addr and hostname -I do not exist on macOS.

How to Find Your IP Address from the macOS Terminal

by Marcus Reeve
August 23, 2026July 19, 2026

The macOS way to find your IP address from the terminal isn’t the Linux ip addr or hostname -I — neither of those exists here. It’s ipconfig getifaddr, with one wrinkle: you have to point…

macOS terminal showing caffeinate -i ./backup.sh with the note 'awake until it finishes', beside a table of caffeinate -d (keep the display on), -t 3600 (stay awake for one hour), -w PID (until a process ends), and pmset -g assertions (see what's keeping it awake).

How to Prevent Your Mac from Sleeping (caffeinate)

by Marcus Reeve
August 21, 2026July 19, 2026

macOS has a built-in command for keeping your Mac awake — caffeinate — so there’s no app to install. Its most useful trick is wrapping a command so the Mac stays up for exactly as…

macOS terminal showing xcode-select --install, next to two cards comparing the Command Line Tools (git, clang, make; a few hundred MB; what most people need) with full Xcode (the full IDE; 10+ GB from the App Store; only to build and ship apps).

How to Install the Xcode Command Line Tools on macOS

by Marcus Reeve
August 18, 2026July 19, 2026

Most command-line development on a Mac needs only the Xcode Command Line Tools — the compilers, git, and make, a few hundred megabytes — not the full multi-gigabyte Xcode IDE. Here’s how to install just…

Table of GNU-to-BSD command differences on macOS: find -printf becomes find -ls or -exec stat; sed -i needs an empty ''; date -d becomes date -v or -j -f; stat -c becomes stat -f; with a note that brew install coreutils provides gdate, gstat, and greadlink.

Why Your Linux Commands Fail on macOS (BSD vs GNU)

by Marcus Reeve
August 15, 2026July 19, 2026

macOS’s command-line tools come from BSD, not the GNU coreutils that ship with most Linux distributions. They cover the same ground, but their flags don’t always match — so a command copied straight from a…

$Two-column table comparing GNU sed on Linux with BSD sed on macOS: sed -i needs an empty '' argument (sed -i '' 's/.../'); \+ is literal so use -E; \U case conversion is unsupported so install gsed; with a footer noting -i.bak for backups, -E for + ? |, and that \n now works.$

The sed Command on macOS: What’s Different from Linux

by Marcus Reeve
August 12, 2026July 19, 2026

macOS ships BSD sed at /usr/bin/sed, not the GNU version Linux uses. Most substitutions work the same, but a few differences turn a copied-from-Linux command into a cryptic error — and the -i flag is…

Two-column table comparing GNU find on Linux with BSD find on macOS: find -name without a path is illegal on macOS (needs find . -name); -printf gives unknown primary or operator; -regextype is replaced by find -E . -regex; find --version gives illegal option; while -type, -iname, -delete, -maxdepth and -exec + work the same.

The find Command on macOS: What’s Different from Linux

by Marcus Reeve
August 10, 2026July 19, 2026

macOS ships the BSD version of find at /usr/bin/find, not the GNU findutils version most Linux distributions use. Most of what you know carries over unchanged — but a handful of habits from Linux tutorials…

macOS Terminal showing zsh: command not found: gti after a typo, beside a table of the five causes and their one-command fixes: typo (command -v), not installed (brew install), not on PATH (add to ~/.zprofile), just installed (rehash), and local script (./script with chmod +x).

“zsh: command not found” on macOS: Causes and Fixes

by Marcus Reeve
August 7, 2026July 19, 2026

When the Terminal prints zsh: command not found: something, it means zsh looked through every directory on your PATH and didn’t find a program by that name. zsh has been the default shell since Catalina…