Formatting of help

[kstrafe]

I wish for argbash to be able to format its help output such that it is aligned. An example is python3's output:

-u     : force the stdout and stderr streams to be unbuffered;
         this option has no effect on stdin; also PYTHONUNBUFFERED=x
-v     : verbose (trace import statements); also PYTHONVERBOSE=x
         can be supplied multiple times to increase verbosity
-V     : print the Python version number and exit (also --version)
         when given twice, print more information about the build
-W arg : warning control; arg is action:message:category:module:lineno

This is much easier to read than argbash's output.

[matejak]

Argbash has the docopt output, which is available at compile-time.
Formatting the output at script run-time is more tricky, as the general aim is to keep the bash code minimal.

[kstrafe]

What I mean is that the generated help function for a script outputs like python, not what argbash itself outputs on its own help.

[matejak]

In order to fix this, the following info is needed:

• Is it possible to determine the terminal width, so the output can be adjusted? I guess that this is what the Python interpreter does.
• What portable features of the printf builtin can be used to use this terminal width info in bash?

[kstrafe]

1. Yes. tput cols will give you the terminal width on linux.
2. We can use the %-Ns specifier to give fixed spaces to strings, but we'll need to ensure that all printed strings fit within the length. We can use the maximum column width to align to.

[matejak]

If anybody could come up with a proof-of-concept Bash help function, that would be great. I can then wire it up with the Argbash core. @BourgondAries you seem to be really close with that tput and printf comments, could you maybe post a print_help prototype?

[djr7C4]

Thanks for writing argbash! I have been using it together with the interpreter hack mentioned in another issue.

The lack of this feature (as well as #147) are what is currently stopping me from using argbash in certain scripts. I wrote the following which I think does a nicer jobs of formatting the help string (though differently than suggested above). Let me know what you think. It prints stuff like the following.

This is a very very long help string that goes on seemingly without end for longer than anyone
would want it to and then it just continues even further providing the user with a great
deal of unnecessary verbosity.

Usage: ./argbash-82-proof-of-concept [--length <arg>] [-o|--option <arg>] [-e|--extraoption
    <arg>] [-v|--(no-)verbose] [-h|--help] <character>

    -o, --option: A option with short and long flags and default. This is a very very long
        help string that goes on seemingly without end for longer than anyone would want it to
        and then it just continues even further providing the user with a great deal of
        unnecessary verbosity. (default: 'bool')

    -e, --extraoption: A option with short and long flags and default. This is a very very
        long help string that goes on seemingly without end for longer than anyone would want
        it to and then it just continues even further providing the user with a great deal of
        unnecessary verbosity. (default: 'bool')

    -e, --extraoption: A option with short and long flags and default. This is a very very
        long help string that goes on seemingly without end for longer than anyone would want
        it to and then it just continues even further providing the user with a great deal of
        unnecessary verbosity. (default: 'bool')

    -h, --help: Prints help

See http://ix.io/4hLV for the script.