[alsa-devel] [PATCH 01/35] axfer: add an entry point for this command

[Takashi Iwai]

On Wed, 14 Nov 2018 17:05:49 +0100,
Takashi Sakamoto wrote:
> 
> Hi,
> 
> On Tue, 13 Nov 2018, Takashi Iwai wrote:
> 
> > On Tue, 13 Nov 2018 07:41:13 +0100,
> > Takashi Sakamoto wrote:
> >>
> >> This commit adds a new command, 'axfer' ('ALSA transfer'), to transfer data
> >> frames described in asound.h. This command is intended to replace current
> >> aplay. The most of features and command line parameters come from aplay as
> >> much as possible, while it has more better feature and code to maintain.
> >>
> >> This commit adds an entry point for this command. Current option system of
> >> aplay is still available, while this command has a sub-command system like
> >> commands in iproute2.
> >>
> >> Currently, two sub-commands are supported; 'list' and 'transfer'. The
> >> 'list' sub-command has the same effect as '-l' and '-L' options of aplay.
> >> The 'transfer' sub-command has the same effect as the main feature of
> >> aplay. For the sub-command system, an option for stream direction is
> >> required; '-P' for playback and '-C' for capture. If you create symbolic
> >> links to this binary for aplay/arecord, please execute:
> >> $ ln -s axfer aplay
> >> $ ln -s axfer arecord
> >>
> >> Actual code for each sub-command will be implemented in later commits.
> >>
> >> Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
> >
> > Although all patches have been merged, below are a few suggestions:
> >
> > - Please make help working.  It took some time for me until figuring
> >  out the fact that the direction option is mandatory, for example.
> >
> > - The input/output from/to a terminal can be checked via isatty().
> >  That allows us to see garbages by a mistakenly started command.
> 
> If my understanding is correct, usage of 'isatty(3)' can return error
> in a case that users just run 'axfer transfer -P (-)'.

Right.

> In current
> implementation, axfer continues to call of 'read(2)' and receive
> '-EAGAIN' till receiving teminate signals.

The playback isn't too bad (although I don't see any useful scenario,
either).  The worse is the capture that prints junk texts that
sometimes mandates the terminal reset.

> > - A man page.  (I thought Debian mandates it?)
> 
> I have a plan to write help/man in this development period, within
> this year.

Not only children cheer for a Christmas gift, yeah :)


thanks,

Takashi


> > In anyway, thanks for your hard work!
> 
> Yep. I'm a bit exhausted from this tough work, and need refresh time.
> Anyway, thank you for applying this PR.
> 
> 
> Regards
> 
> Takashi Sakamoto
>