bug#33468: A bug with yes and --help

[Assaf Gordon]

Hello Eric,

On 2019-01-12 8:42 a.m., Eric Blake wrote:
> On 1/11/19 6:23 PM, Assaf Gordon wrote:
>
> > -  optind = 0;
> > +  optind = 1;
>
> Ouch. You're hitting the portability problem of the difference between
> BSD and glibc.
>
> > Otherwise many things fail like so:
> >
> >    $ ./src/dd
> >    ./src/dd: unrecognized operand ‘./src/dd’
> >    Try './src/dd --help' for more information.
>
> That's the symptoms on BSD for optind = 0 (there, you HAVE to use
> optreset=optind=1 for a complete reset; or plain optind=1 for a soft
> reset where the man page is not clear if it will always work).  But on
> glibc, optind=1 does a soft reset (works if the optstring does not start
> with '-' or '+' and if you did not change POSIXLY_CORRECT), but MUST use
> optind = 0 if you want a hard reset.

I only tested on Debian Stretch (with Debian GLIBC 2.24-11+deb9u3),
did not yet test on BSDs.

With "optind=1", I see the following:

===
  $ ./src/hostid
  ec68f06c

  $ ./src/sleep
  ./src/sleep: missing operand
  Try './src/sleep --help' for more information.

  $ ./src/uptime
   11:14:05  up 23 days 21:23,  4 users,  load average: 1.16, 1.05, 0.52

  $ ./src/users
  gordon gordon gordon gordon

  $ ./src/nohup
  ./src/nohup: missing operand
  Try './src/nohup --help' for more information.

  $ ./src/dd       ## waits for CTRL-C
  ^C
  0+0 records in
  0+0 records out
  0 bytes copied, 1.10243 s, 0.0 kB/s

  $ ./src/yes | head -n1
  y
===

With "optind=0" I see the following:

===
  $ ./src/hostid
  ./src/hostid: extra operand ‘./src/hostid’
  Try './src/hostid --help' for more information.

  $ ./src/sleep
  ./src/sleep: missing operand
  Try './src/sleep --help' for more information.

  $ ./src/users

  $ ./src/users | od -tx1
  0000000 02 e2 03 0a
  0000004

  $ ./src/users /var/log/wtmp
  ./src/users: extra operand ‘/var/log/wtmp’
  Try './src/users --help' for more information.

  $ ./src/nohup
  ./src/nohup: ignoring input and appending output to 'nohup.out'
  ^C

  $ ./src/dd
  ./src/dd: unrecognized operand ‘./src/dd’
  Try './src/dd --help' for more information.

  $ ./src/yes | head -n1
  ./src/yes
===

Perhaps "parse_gnu_standard_options_only" should use "_getopt_long_r"
and avoid the need to reset anything?

regards,
 - assaf