I saw this list of macOS CLI Commands. I knew about most of these, and use many like pbcopy and pbpaste often.

sips looks pretty neat—I’ve usually just whipped up quick Ruby scripts with the mini_magick gem.

Hopefully people comment with a few more goodies in the Hacker News comments.

A few hours later, and here are more goodies:

# You can use sips together with iconutil to generate a complete .icns file
# for your app from a single 1024 by 1024 PNG without any third party software:
mkdir MyIcon.iconset
cp Icon1024.png MyIcon.iconset/icon_512x512@2x.png
sips -z 16 16     Icon1024.png --out MyIcon.iconset/icon_16x16.png
sips -z 32 32     Icon1024.png --out MyIcon.iconset/icon_16x16@2x.png
sips -z 32 32     Icon1024.png --out MyIcon.iconset/icon_32x32.png
sips -z 64 64     Icon1024.png --out MyIcon.iconset/icon_32x32@2x.png
sips -z 128 128   Icon1024.png --out MyIcon.iconset/icon_128x128.png
sips -z 256 256   Icon1024.png --out MyIcon.iconset/icon_128x128@2x.png
sips -z 256 256   Icon1024.png --out MyIcon.iconset/icon_256x256.png
sips -z 512 512   Icon1024.png --out MyIcon.iconset/icon_256x256@2x.png
sips -z 512 512   Icon1024.png --out MyIcon.iconset/icon_512x512.png
iconutil -c icns MyIcon.iconset

# Generate .ico with ffmpeg (not strictly macOS, but still neat)
ffmpeg -i MyIcon.iconset/icon_256x256.png icon.ico

Someone else mentioned the ditto command, which is a more advanced version of cp for macOS. Seems like a great choice for merging directories.

plutil has a way to convert binary plist files to XML:

plutil -convert xml1 -o out.xml in.plist

networkQuality can show you the quality of your network connection, like Speedtest CLI:

==== SUMMARY ====
Uplink capacity: 1.955 Mbps
Downlink capacity: 352.037 Mbps
Responsiveness: Low (100 RPM)
Idle Latency: 42.875 milliseconds