Would this (o) be very difficult to add?

Would this (o) be very difficult to add?

[DervishD]

    Hi all :)

    Sometimes we want to do globbing and sort the output randomly:
when generating playlists, when generating image slideshows, etc...
So I've thought that it would be good if we can do:

    print -l *(or)
    print -l *(Or)

    Please note that since the sort criteria is 'random', (o) and (O)
have exactly the same effect...

    If you use qsort or something like that, a quite simple
pseudo-random (we want apparent chaos, not cryptographical quality)
order can be achieved using a comparison function that generates a
random integer and returns, for example, 'first is greater' if the
random integer is even, 'second is greater' if the random integer is
odd and 'equal' if the random integer is 0. In fact, if you use the
standard qsort behaviour, you can return the random integer minus the
randomize range, so it will be <0, 0 or >0 appropriately.

    If this is not much bloat, I would love having such a glob
qualifier :)

    Raúl Núñez de Arenas Coronado

-- 
Linux Registered User 88736
http://www.pleyades.net & http://raul.pleyades.net/

Re: Would this (o) be very difficult to add?

[Bart Schaefer]

On Sep 23,  6:12pm, DervishD wrote:
}
}     Sometimes we want to do globbing and sort the output randomly:
} when generating playlists, when generating image slideshows, etc...

Try this:

	print -lP *(e:'REPLY=%0(l..$RANDOM)"$REPLY"':)


-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net   

Re: Would this (o) be very difficult to add?

[DervishD]

    Hi Bart :)

 * Bart Schaefer <schaefer@brasslantern.com> dixit:
> }     Sometimes we want to do globbing and sort the output randomly:
> } when generating playlists, when generating image slideshows, etc...
> Try this:
> 	print -lP *(e:'REPLY=%0(l..$RANDOM)"$REPLY"':)

    Very clever, I'd never have thought about something like that...
I tried something like this, inserting $RANDOM before each filename
in a for loop, redirecting to sort (or using the (o) modifier to sort
the list by name) and using cut (or ${...##...}) for getting rid of
the random number. No doubt your example is better. Far better ;))

    Anyway I keep thinking that the (or) modifier would be useful ;)

    Thanks a lot for your answer. It's a neat, short and fast way of
generating random lists :)))

    Raúl Núñez de Arenas Coronado

-- 
Linux Registered User 88736
http://www.pleyades.net & http://raul.pleyades.net/

Re: Would this (o) be very difficult to add?

[DervishD]

    Hi Bart and zsh workers :))

 * DervishD <raul@pleyades.net> dixit:
>  * Bart Schaefer <schaefer@brasslantern.com> dixit:
> > }     Sometimes we want to do globbing and sort the output randomly:
> > } when generating playlists, when generating image slideshows, etc...
> > Try this:
> > 	print -lP *(e:'REPLY=%0(l..$RANDOM)"$REPLY"':)
>     Very clever, I'd never have thought about something like that...

    This solution has worked great for generating, for example, a
file containing the names of the files in random order. The problem
is that I cannot use this in a command: command $(print -lP...)
results in 'command file name 1 file name 2', unquoted :((( Strictly
speaking, characters like '[' are quoted, but spaces arent, and the
names which I want to order randomly usually contain spaces.

    I've tried something like 'array=($(print -lP...))', but since
the expansion has spaces unquoted, the elements of the array end up
being 'file', 'name', '2', 'file', 'name', '1', and so on.

    How can I get the result of the 'e' glob qualifier quoted, so I
can use command $(print -lP...) and get a working command?

    Thanks a lot :))

    Raúl Núñez de Arenas Coronado

-- 
Linux Registered User 88736
http://www.pleyades.net & http://raul.pleyades.net/

Re: Would this (o) be very difficult to add?

[Bart Schaefer]

On Sep 27,  1:18pm, DervishD wrote:
} Subject: Re: Would this (o) be very difficult to add?
}
} [...] I cannot use this in a command: command $(print -lP...)
} results in 'command file name 1 file name 2', unquoted :(((

Since you're using "print -l" you have the filenames one per line.
Therefore, just quote the entire thing and split the output on newlines,
and all should be well:

    command ${(f)"$(print -lP ...)"}

Zsh is even clever enough to deal properly with nested double quotes
when ${...} or $(...) are involved.

Re: Would this (o) be very difficult to add?

[DervishD]

    Hi Bart :)

    Nice to see you back ;)

 * Bart Schaefer <schaefer@brasslantern.com> dixit:
> } [...] I cannot use this in a command: command $(print -lP...)
> } results in 'command file name 1 file name 2', unquoted :(((
> Since you're using "print -l" you have the filenames one per line.
> Therefore, just quote the entire thing and split the output on newlines,
> and all should be well:
>     command ${(f)"$(print -lP ...)"}

    Oh, I'm really *stupid*. I was trying the same but with the (j)
flag... I was using it to fold instead of the correct (f), and all I
got was an 'error in flags' message :((((

    Thanks, this solve entirely my problem :)) 

    Another thing I'm doing with all this is storing the generated
list on an array, because sometimes I wan't to have the list passed to
a command and stored in a file, and I do with the array:

    array=(${(f)...})
    command $array
    print -l $array > file.list

    Can this be done directly in the command line for the 'command',
or I'd better stuck with the array and the redirection? In fact for
me is very convenient to have the list on an array, for further
manipulation, for example, it's just curiosity, not need ;)

> Zsh is even clever enough to deal properly with nested double quotes
> when ${...} or $(...) are involved.

    Good boy, Zsh, good boy ;)) Thanks a lot for your answer :)

    Raúl Núñez de Arenas Coronado

-- 
Linux Registered User 88736
http://www.pleyades.net & http://raul.pleyades.net/

Re: Would this (o) be very difficult to add?

[Bart Schaefer]

On Sep 28, 11:25am, DervishD wrote:
}
}     Another thing I'm doing with all this is storing the generated
} list on an array, because sometimes I wan't to have the list passed to
} a command and stored in a file, and I do with the array:
} 
}     array=(${(f)...})

If you're storing in an array, you should skip the $(print -lP ...) part
(which requires forking a subshell) and do this instead:

    array=( *(e:'REPLY="%0(l..$RANDOM)$REPLY"':) )
    array=( ${(%)array} )

}     command $array
}     print -l $array > file.list
} 
}     Can this be done directly in the command line for the 'command',
} or I'd better stuck with the array and the redirection?

I'm not entirely sure, but I suspect you mean something like this:

    command ${(f)"$(print -lP ... >&1 > file.list)"}

This only works if you have the MULTIOS option set; if you don't use that,
you need something like

    command ${(f)"$(print -lP ... | tee file.list)"}

Re: Would this (o) be very difficult to add?

[DervishD]

    Hi Bart :)

 * Bart Schaefer <schaefer@brasslantern.com> dixit:
> }     array=(${(f)...})
> If you're storing in an array, you should skip the $(print -lP ...) part
> (which requires forking a subshell) and do this instead:
>     array=( *(e:'REPLY="%0(l..$RANDOM)$REPLY"':) )
>     array=( ${(%)array} )

    Oh, I forgot the (%) flag and I stuck with the '-P' for
interpreting %0. BTW, how works exactly the %0(l..$RANDOM)
construction? I know that the (l..) is for padding with a random
number, and I suppose the %0 is there for avoiding printing it, but I
don't know how it exactly works... If you're tired of this feel free
to ignore me ;) For me, %0 can only be a job specification, because I
don't know about any prompt escape that fits just %NUMBER :?

> }     Can this be done directly in the command line for the 'command',
> } or I'd better stuck with the array and the redirection?
> I'm not entirely sure, but I suspect you mean something like this:
>     command ${(f)"$(print -lP ... >&1 > file.list)"}

    Yes, it will do. I just didn't know where should I do the
redirection (or if it was possible at all...). Thanks a lot for
showing :))

    Raúl Núñez de Arenas Coronado

-- 
Linux Registered User 88736
http://www.pleyades.net & http://raul.pleyades.net/