Re: getopt helpWanted

[wobbles via Digitalmars-d-learn]

On Wednesday, 29 April 2015 at 22:02:29 UTC, novice2 wrote:

Hello.

Help me please to understand, how to show usage help to user, 
who enter wrong options?

For example, user not provided required filename.
I want to show error message, and program usage help text.
But likely getopt don't provide help text until valid options 
will be parsed.


Reduced code:
///
import std.stdio: writefln;
import std.getopt;

void main (string[] args)
{
  string fname;
  GetoptResult helpInfo;

  try
  {
helpInfo = getopt(
  args,
  std.getopt.config.required, file|f, File name, 
fname);


writefln(Options parsed: fname=%s, fname);
  }
  catch(Exception e)
  {
writefln(\nERROR: %s, e.msg);
defaultGetoptPrinter(Program usage:, helpInfo.options);
  }
}
///

Output:
ERROR: Required option file|fwas not supplied
Program usage:


Also, I suggest you look at docopt:
http://code.dlang.org/packages/docopt

It makes the whole parsing of CLI arguments very nice and easy.

Re: getopt helpWanted

[novice2 via Digitalmars-d-learn]

Thank you, Brian!

getopt helpWanted

[novice2 via Digitalmars-d-learn]

Hello.

Help me please to understand, how to show usage help to user, who 
enter wrong options?

For example, user not provided required filename.
I want to show error message, and program usage help text.
But likely getopt don't provide help text until valid options 
will be parsed.


Reduced code:
///
import std.stdio: writefln;
import std.getopt;

void main (string[] args)
{
  string fname;
  GetoptResult helpInfo;

  try
  {
helpInfo = getopt(
  args,
  std.getopt.config.required, file|f, File name, fname);

writefln(Options parsed: fname=%s, fname);
  }
  catch(Exception e)
  {
writefln(\nERROR: %s, e.msg);
defaultGetoptPrinter(Program usage:, helpInfo.options);
  }
}
///

Output:
ERROR: Required option file|fwas not supplied
Program usage:

Re: getopt helpWanted

[Brian Schott via Digitalmars-d-learn]

What you're trying to do is currently impossible. I filed a bug 
(https://issues.dlang.org/show_bug.cgi?id=14525) because what 
you're trying to do really should be possible.


import std.stdio : writefln;
import std.getopt;

void main(string[] args)
{
string fname;
try
{
getopt(args, std.getopt.config.required, file|f, File 
name, fname);

writefln(Options parsed: fname=%s, fname);
}
catch (GetOptException e)
{
writefln(\nERROR: %s, e.msg);
auto p = [placeholder];
auto r = getopt(p, file|f, File name, fname);
defaultGetoptPrinter(Program usage:, r.options);
}
}