FLAP v2.5.1 released

Announcements
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FLAP v2.5.1 is out.

Fortran command Line Arguments Parser

FLAP (Fortran command Line Arguments Parser) is a pure Fortran 2018 library for building command line interfaces. You describe your command line once, with a handful of calls; FLAP parses it, reads the environment and the configuration files, checks every value, and writes the help, the errors, the man page and the shell completions.

What it covers:

  • options, positionals, flags and --x/--no-x pairs, counters, repeatable options, lists and KEY=VALUE maps
  • typed values: one get for every integer and real kind, logicals and strings
  • validation: required options, choices, numeric ranges, path checks, mutually exclusive sets
  • git-style commands, with aliases and shared options
  • values from the command line, environment variables and INI files, with the source of each value reported
  • generated help, man page, Markdown, and completion scripts for bash, zsh, fish and PowerShell
  • errors with “did you mean” suggestions
  • and much more…

A minimal program:

program greet
use flap
implicit none
type(command_line_interface) :: cli
character(32)                :: name
integer                      :: times, i, error

call cli%init(progname='greet', description='Greet someone')
call cli%add(positional=.true., position=1, help='Who to greet', required=.true., metavar='NAME')
call cli%add(switch='--times', switch_ab='-t', help='How many times', def='1', min='1', max='5')
call cli%parse(error=error)
if (error /= 0) stop 1
call cli%get(position=1, val=name, error=error)
call cli%get(switch='--times', val=times, error=error)
do i = 1, times
  print '(A)', 'Hello '//trim(name)
enddo
endprogram greet

FLAP builds with FoBiS, fpm, CMake or Make, is tested with GNU gfortran, NVIDIA nvfortran and Intel ifx, and is multi-licensed (GPL v3, BSD 2-Clause, BSD 3-Clause, MIT).

Feedback, issues, and contributions are welcome.

Stefano

3 Likes
2

Very interesting, definitely will take a look into this!

Pretty sure this is the first fortran lib that does this (afaik), might use it for my next project.

1 Like