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Re: sort --random-sort
From: |
Jim Meyering |
Subject: |
Re: sort --random-sort |
Date: |
Mon, 28 Nov 2005 11:09:12 +0100 |
Hi Paul,
Paul Eggert <address@hidden> wrote:
> I'm puzzled as to why, in this day and age, shred (and any other
> programs that might need lots of hard-to-guess random numbers) needs
> to have its own random number generator. Why can't such programs just
> read /dev/urandom? Is it because they need to fall back on something
> on hosts that lack /dev/urandom?
I suspect that was Colin's (shred-author's) motivation.
If we were to use /dev/urandom, we'd have to handle unusual
cases like open failure, EOF, and read error, and hence would
need a fall-back position, regardless.
I do agree that it'd be better to use /dev/urandom, when possible.
The resulting interface to a gnulib-like module would have to record
state, including a file descriptor or FILE* as well as state for a
fall-back random number generator.
> Also, the more I think about it, the less I like folding this stuff
> into 'sort'. It really should be a separate program, as it's an ill
> fit for 'sort'.
I too like the idea of a separate program to permute its input lines,
but there are some applications for which permuting only lines with,
say the same primary sort key, is practical:
http://lists.gnu.org/archive/html/bug-coreutils/2005-02/msg00005.html
I'd welcome a separate program, in addition to the sort option.
> How about this as an initial cut for an interface? Let's call the
> program 'rand' (perhaps we can think of a better name later). By
I'd expect a program named `rand' to output random numbers.
Maybe something like `permute' or `pmt'?
> default, 'rand' reads lines from stdin and outputs a random
> permutation of those lines. If one operand is given, 'rand' reads
> from the named input file rather than from standard input. Here are
> some options:
>
> --count NLINES
It needs a --seed=SEED option, too, of course.
- Re: sort --random-sort, (continued)
- Re: sort --random-sort, Frederik Eaton, 2005/11/26
- Re: sort --random-sort, Jim Meyering, 2005/11/26
- Re: sort --random-sort, Andreas Schwab, 2005/11/26
- Re: sort --random-sort, Frederik Eaton, 2005/11/26
- Re: sort --random-sort, Jim Meyering, 2005/11/29
- Re: sort --random-sort, Paul Eggert, 2005/11/29
- Re: sort --random-sort, Frederik Eaton, 2005/11/30
- Re: sort --random-sort, Jim Meyering, 2005/11/30
- Re: sort --random-sort, Frederik Eaton, 2005/11/30
- Re: sort --random-sort, Paul Eggert, 2005/11/28
- Re: sort --random-sort,
Jim Meyering <=
- Re: sort --random-sort, Frederik Eaton, 2005/11/28
Re: sort --random-sort, ThMO, 2005/11/29