in reply to Filenames based on timestamp

you could use the time that you've got available, then increment a counter at the end of the filename. 
my $time = time();
my $counter = 0;
while(-e "$time_$counter") { $counter++; }
open(F, ">$time_$counter") or die "blah blah $!";

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that way you get unique filenames that have a timestamp in them, they just have an extra number at the end.

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Re^2: Filenames based on timestamp
by Aristotle (Chancellor) on Jun 27, 2002 at 17:02 UTC
    This is prone to race conditions when several processes are involved. Between the -e test and the actual file creation, a file of the name in question may have been created by another process.

    Makeshifts last the longest.

[reply]
      that's true. you could work around that by also included a PID in the filename. 
        while(-e "$time_$$_$counter") { $counter++; }
  open(F, ">$time_$$_$counter");

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      of course, then the filenames won't necessarily be in ascending order chronologically.
[reply]
[d/l]
        what about multiple threads :-)

        page 572-574 of camel3 suggests something along the lines of... 
        $fn = "filename_20020723141223_";
my $c = 1;
do {
    $fn .= "$c";
    $c++;
} until sysopen(FH, $fn, O_RDWR | O_CREAT | O_EXCL, 0600);
# now do I/O using $fh handle...

        [download]
[reply]
[d/l]

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