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• Generate random characters for cryptographic use

  04/04/25, 10:30 PM

  Shell snippet to generate a random string of characters; use when in need of a cryptographic secret.

  head /dev/urandom \
  | LC_ALL=C tr -dc 'A-Za-z0-9!"#$%&'\''()*+,-./:;<=>?@[\]^_`{|}~' \
  | head -c 24

  • Setting LC_ALL=C environment variable prevents system locale settings from affecting output
  • tr utility will strip out non-printable characters from the randomess source /dev/random
  • The supplied regex will allow all alphanumeric characters, plus characters from the OWASP password special characters list
  • Adjust the length of the resulting string with the -c flag of the head utility

  Use the snippet below to copy the string to your system clipboard.

  head /dev/urandom \
  | LC_ALL=C tr -dc 'A-Za-z0-9!"#$%&'\''()*+,-./:;<=>?@[\]^_`{|}~' \
  | head -c 24 \
  | pbcopy

  source

• Find and replace a term in all files of a directory

  04/04/25, 10:00 PM

  Using ripgrep combined with sed utilities, use the snippet below:

  rg --files-with-matches <term> | xargs sed -i '' 's/<term>/<new-term>/g'

  source