Home > Archive > Unix Programming > April 2005 > Re: Shouldn't getopt_long() return ':' for options requiring an
You are viewing an archived Text-only version of the thread.
To view this thread in it's original format and/or if you want to reply to
this thread please [click here]
| Author |
Re: Shouldn't getopt_long() return ':' for options requiring an
|
|
| Måns Rullgård 2005-04-24, 8:57 pm |
| "Eric Lilja" <mind er_thisshouldberemoved@gmail.com> writes:
> Hello, consider this C program and its accompanying test script:
[...]
> As you can see, getopt_long() returns '?' for the case where the option
> requires arguments and none was supplied, I was under the impression that it
> should return ':' for that case and '?' for unknown options (it prints the
> correct diagnostic, though). Is this a bug in the implementation of
> getopt_long() on my system or are there simply different valid variants of
> the implementation?
man 3 getopt:
If the first character (following any optional '+'or '-' described
above) of optstring is a colon (':'), then getopt() returns ':' instead
of '?' to indicate a missing option argument.
--
Måns Rullgård
mru@inprovide.com
| |
| Måns Rullgård 2005-04-24, 8:57 pm |
| "Eric Lilja" <minder_thisshouldberemoved@gmail.com> writes:
> "Måns Rullgård" <mru@inprovide.com> wrote:
>
> Hmm, I must be daft or something, but does that mean that getopt_long() only
> returns ':' if the user had supplied --:option_with_argument on the command
> line?
It means the string passed to getopt() (short_options in your example)
should start with a colon.
--
Måns Rullgård
mru@inprovide.com
| |
| Måns Rullgård 2005-04-25, 8:58 am |
| "Eric Lilja" <minder_thisshouldberemoved@gmail.com> writes:
> Thank you, Måns, changing short_options from "" to ":" seems to work, then
> '?' is returned for unknown options and ':' is returned for options that
> require a value but none was supplied. Does this change to short_options
> alter the behaviour in any other way?
If the man page is correct, no.
--
Måns Rullgård
mru@inprovide.com
|
|
|
|
|