Sorting a file and printing it back onto itself

c has asked for the wisdom of the Perl Monks concerning the following question:

i'm printing a new line into a file and then i sort it and print it back onto itself. i'm using the following code for the sorting and printing:

    ## sort the new list of virtusers
    open(FH, $virttmp);

    @virtusers = <FH>;

    close(FH);

    ## write sorted file contents back onto itself
    open(FH, ">$virttmp");

    print FH (sort @virtusers);

    close(FH);
[download]

this seems neat enough, but is there a quicker way to do this? i dont believe that sort can be used on a filehandle, but is this really the most efficient way to get the desired results?

humbly -c

Comment on Sorting a file and printing it back onto itself Download Code

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Re: Sorting a file and printing it back onto itself by Chady (Priest) on Nov 17, 2001 at 20:00 UTC
I think you can minimize multi-opening files by opening once: `open FH, "+>>$virttmp" or die "Cannot open file: $!\n"; seek FH, 0, 0; my @v = <FH>; seek FH, 0, 0; truncate $virttmp, 0; print FH sort @v; close FH;` [download] He who asks will be a fool for five minutes, but he who doesn't ask will remain a fool for life. Chady \| http://chady.net/	[reply] [d/l]
Re: Sorting a file and printing it back onto itself by Zaxo (Archbishop) on Nov 17, 2001 at 22:44 UTC
I'd recommend safety over speed in this. You may not need to lock your file or make a backup, but it's good policy. After Compline, Zaxo	[reply]
Re: Sorting a file and printing it back onto itself by kwoff (Friar) on Nov 18, 2001 at 04:53 UTC
One-liner :) `$ perl -i.bak -0777pe'$_=join"\n",sort(split /\n/),""' users.dat $ cat users.dat.bak me you them she he it we $cat users.dat he it me she them we you` [download]	[reply] [d/l]

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