The answer to this question can be found in one of my projects.

  • dateutils Managing dates and times in the command line.
  • clitoris Test harness for command line utilities.
  • yuck Command-line option parser for C with support for umbrellas.
  • numchk A tool like file(1) for (identification) numbers.
  • glod Command-line tools for the preprocessing stage of NLP workflows.
  • truffle Rolling over futures contracts.
  • cattle Applying corporate action events to time series.
  • echse Processing holiday calendars and trading hours.
  • sample Command-line tool to produce a sample of lines from files.

Other appearances