#!/usr/bin/perl

use autodie;
use Time::HiRes qw(nanosleep);

unless (@ARGV == 2) {
    die "Usage: $0 <path> <str>\n";
}

$|++;
for (1..100_000) {
    open my($fh), ">>", $ARGV[0];
    nanosleep(1_000_000*rand());
    print $fh "$ARGV[1]: $_\n";
    nanosleep(1_000_000*rand());
    close $fh;
}


##</code><code>##

$ wc -l log
$ grep ^1: log | wc -l
$ grep ^2: log | wc -l
...