Useful terminal commands

27.05.2025

•3 min read

•

This post will be different from the others. Instead of presenting a comprehensive tutorial or in-depth explanation, it will function more like a personal repository – a collection of useful programs, terminal commands, and solutions that have worked well for me over time. Think of it as a 'notes to self' section, where I can quickly reference and revisit these gems whenever needed.

Searching

Search phrase inside PDF files

Search for <phrase> in all PDF files (case insensitive, e.g.: .pdf, .PDF) in the current directory (.).

sh
find . -iname "*.pdf" -exec pdfgrep

sh
while true; do
  if ping -c 1 8.8.8.8 &> /dev/null; then
    printf "%s %s\n" "$(date -u +"%Y-%m-%dT%H:%M:%SZ")" success && afplay /System/Library/Sounds/Funk.aiff
  else
    printf "%s %s\n" "$(date -u +"%Y-%m-%dT%H:%M:%SZ")" fail
  fi;
  sleep 5;
done

Option 1: Using openssl and generate random 12 characters password.
```
sh
openssl rand -base64 12
```

Option 2: Generate chars [a-z0-9] (no special chars)

sh
LC_ALL=C bash -c 'head /dev/urandom | tr -dc a-z0-9 | head -c30'

Useful terminal commands

Searching

Search phrase inside PDF files

Check open port on given IP address

Listing

Show all directories and their real sizes (with sort)

Copying

Copy all files of a given type to specific directory

Updating

Testing

Benchmark server effectiveness

Reaching internet connection (macOS)

Saving

Saving file with vim without sudo privileges

Generating

Random passwords

Secure password file for users