Re: -M file test operator

Hello Baryuds, I wrote the following program to try to reproduce your problem, but I wasn't able to. I'd suggest you add a line like this to your program, so you can see just how big a number -M is returning:

print "minus M returns: ", (-M $logfile), "\n";

#!/usr/bin/perl

use strict;
use warnings;

my $logfile = "file.log";
my $internal = 0;
if ($internal)
{
    # create a logfile
    open LOGFILE, ">$logfile" or die "can't open $logfile: $!";
    print LOGFILE "This is a test\n";
    close LOGFILE or die "can't close $logfile: $!";
}
else
{
    # create logfile externally
    system("./write-log");
}

# sleep?
sleep 3;

print "minus M returns: ", (-M $logfile), "\n";
# test modification time
if (-M $logfile > 0)
{
    print "The logfile generated by 3rd party script is not new\n";
    exit(1);
}
else
{
    print "It's a new logfile! Hoooray!\n";
}

__END__
[download]

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Re^2: -M file test operator by bayruds (Acolyte) on Jul 29, 2004 at 01:42 UTC
`Hi Beable I ran it a couple of times, These are the values I got: # Using $mtime = (-M $logfile); MTIME: 1.15740740740741e-05 MTIME: 0.000104166666666667 Thanks for your reply. bayruds` [download]	[reply] [d/l]
Re^3: -M file test operator by beable (Friar) on Jul 29, 2004 at 06:04 UTC
Hi Bayruds, here is a program to find out how old the log file actually is. It turns out that we are talking about 1 to 9 seconds old. Is that too old for you? If that seems like a reasonable age, I'd suggest you change your "-M" test line to something like: `# see if the file is more than about one hour old if (-M $logfile > 0.042) { ... }` [download] Here's the program. Somebody will probably produce a one-liner to do this now. `#!/usr/bin/perl use strict; use warnings; my $secs_per_day = 60 * 60 * 24; while (my $line = <DATA>) { chomp $line; if ($line =~ m/MTIME:\s+(.)/) { my $time = $1; my $secs = $time $secs_per_day; print "$time days is $secs second(s)\n"; } } __END__ Output: 1.15740740740741e-05 days is 1 second(s) 0.000104166666666667 days is 9.00000000000003 second(s) __DATA__ MTIME: 1.15740740740741e-05 MTIME: 0.000104166666666667` [download]	[reply] [d/l] [select]