Calculate MD5 or SHA256 file checksum from macOS cli
brew install coreutils md5sum ${filename} or sha256sum ${filename}
Tech Notes (36)
Send HTML email from macOS Safari via Mail app
Create the HTML email Open it in Safari and make sure it looks good Go to the Share button and…
View TLS certs for HTTPS sites from the command line
echo | openssl s_client -showcerts -servername {domain} -connect {domain}:443 2>/dev/null | openssl x509 -inform pem -noout -text echo | openssl…
Setup fail2ban to block bots and script kiddies accessing a Node.js app behind an nginx reverse proxy
Setup fail2ban to stop bot HTTP and HTTPS connections on nodejs apps running through nginx proxy_pass Install fail2ban: sudo yum…
Shrink PDF size using Ghostscript
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf Took a 7MB PDF to 700K!
Git show visual map of all branches
git log --graph --decorate --oneline
Create an Encrypted ZIP archive on macOS command line (cli)
zip -er FILENAME.zip FILESorFOLDERStoCOMPRESS ex: zip -er ThisFolder.zip This\ Folder/ You will be prompted for a password and will have…
Search JSONB embedded array using SequelizeJs
query.$or.push(sequelize.literal(`to_json(array(select jsonb_array_elements("${hook.service.options.name}"."metadata"->'referenceIds') ->> 'id'))::jsonb ?| array['${query.$search}']`));
`nginx` setup to return files with different file extensions
# Allow .jpeg to be requested with .jpg location ~ (.+).jpg(.*) { try_files $uri $1.jpeg$2 =404; } This will try…
Split string on delimiter in Bash
#!/bin/bash # # Script to split a string based on the delimiter declare my_string declare my_array my_string="Ubuntu;Linux Mint;Debian;Arch;Fedora" IFS=';' read…
Error on SCP: `protocol error: mtime.sec not present`
Troubleshoot with scp -vvvv Could be SCP protocol isn’t supported, and you need to use SFTP However, in my case,…
Remove a macOS user's from ability to decrypt FileVault disk
WARNING: don’t do this unless it’s for a secondary user on your Mac. This will prevent any user from decrypting…
UI Scripting in AppleScript
Open the “Accessibility Inspector” app to try to determine each element Example with some UI Scripting for Messages app to…
Find all files that have the same hard link as this file
find . -samefile /path/to/file Keywords: links hardlinks
Crappy Internet connection downloads
export ec=18; while [ $ec -eq 18 ]; do /usr/bin/curl -O -C - "http://www.example.com/a-big-archive.zip"; export ec=$?; done from http://ilovesymposia.com/2013/04/11/automatically-resume-interrupted-downloads-in-osx-with-curl/ sync…
Mount ISO and alternate disk formats in macOS
Make a folder mount point: mkdir mount-folder Use hdiutil to attach the ISO without mounting it: hdiutil attach -nomount linux.iso…