•Re: Limiting log file size

Well, as a first start, I'd try something like this:

#!/usr/bin/perl
my $FILE = "the_log_file";
my $MAXSIZE = 2**20; # 1 meg
exit 0 unless -s $FILE > $MAXSIZE;
@ARGV = $FILE; # set diamond to file
undef $/; # slurp mode
$^I = ""; # enable in-place editing
while (<>) {
    substr($_, 0, $MAXSIZE - length) = ""; # save last portion
    s/.*\n//; # toss one line so it comes out at a line boundary
    print;
}
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-- Randal L. Schwartz, Perl hacker

Comment on •Re: Limiting log file size Download Code

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Re: •Re: Limiting log file size by Juerd (Abbot) on Apr 02, 2002 at 18:10 UTC
undef $/; # slurp mode $^I = ""; # enable in-place editing This sounds like a nice job for Tie::File. `#!/usr/bin/perl -w use Tie::File; use strict; my $max = 512; my $file = 'syslog'; tie my @lines, 'Tie::File', $file; my $size = 0; for my $line (reverse -@lines .. -1) { if (($size += length $lines[$line]) > $max) { splice @lines, 0, (@lines + $line + 1); last; } } untie @lines;` [download] (Didn't use negative splice length, because Tie::Splice seems to be unable to handle it.) U28geW91IGNhbiBhbGwgcm90MTMgY W5kIHBhY2soKS4gQnV0IGRvIHlvdS ByZWNvZ25pc2UgQmFzZTY0IHdoZW4 geW91IHNlZSBpdD8gIC0tIEp1ZXJk	[reply] [d/l]

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Re: •Re: Limiting log file size
by Juerd (Abbot) on Apr 02, 2002 at 18:10 UTC

undef $/; # slurp mode
$^I = ""; # enable in-place editing

This sounds like a nice job for Tie::File.

#!/usr/bin/perl -w
use Tie::File;
use strict;

my $max = 512;
my $file = 'syslog';

tie my @lines, 'Tie::File', $file;

my $size = 0;
for my $line (reverse -@lines .. -1) {
    if (($size += length $lines[$line]) > $max) {
        splice @lines, 0, (@lines + $line + 1);
        last;
    }
}

untie @lines;
[download]

U28geW91IGNhbiBhbGwgcm90MTMgY
W5kIHBhY2soKS4gQnV0IGRvIHlvdS
ByZWNvZ25pc2UgQmFzZTY0IHdoZW4
geW91IHNlZSBpdD8gIC0tIEp1ZXJk

[reply]
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