> Dear Quentin,
Hi Laslo,
> > I agree, yes is neither a benchmark tool nor a data generator, it just
> > outputs 'y' for piping into other commands.
> > Keep it simple.
>
> I agree with you in general, but are we really "optimizing" yes(1) here
> for the sake of performance? This looks to me like a case of premature
> optimization.
To be honest yes, this reads as bikeshedding, but on the other hand, a
simple tool as yes is quite complicated, at least for an sbase
implementation.
> We don't know if a script relies on the behaviour of yes(1) printing
> all passed strings repeatedly. So, even though the tool is not
> standardized by Posix the common "consensus" is that
>
> - with no arguments, it shall print y and a newline repeatedly.
> - with arguments, it shall print them, comma separated, followed by
> newline, repeatedly.
Where did you get this was the common consensus?
This is the GNU behaviour, ie not a consensus.
The yes(1) rationale is to output a 'y' character for piping into
interactive tool's stdin and make them batchable.
The tool lets you output a custom string which would be passed to its
argument, so when a user wants yes to output anything else, it's a
simple matter of passing it on the command line.
The consensus here is that yes takes a parameter, at least one.
So if one wants to output a string, that's simple:
yes 'my very long string with arguments'
or
yes "$foo $bar $baz"
Done.
> The point about readability is a good one. I will even take the blame
> for writing it as it is now. However, you could greatly improve
> readability without sacrificing features/performance. The line
>
> argv0 = *argv, argv0 ? (argc--, argv++) : (void *)0;
>
> is used in many places in sbase and is more or less an idiom. The
> entire tool itself could then be written as follows. We can even
> remove the checks consequently within the loop, which could be regarded
> as a "performance" improvement.
>
> int i;
>
> argv0 = *argv, argv0 ? (argc--, argv++) : (void *)0;
>
> if (argc == 0) {
> for (;;) {
> fputs("y\n", stdout);
> }
> } else {
> for (;;) {
> for (i = 0; i < argc; i++) {
> fputs(argv[i], stdout);
> fputc(' ', stdout);
> }
> fputc('\n', stdout);
> }
> }
And then this becomes quite simple, if yes gets argc > 1, printf
argv[1], otherwise print 'y'.
> What do you think? Patch is attached.
I think this answers the question ;)
