Perl的flock文件锁单实例运行
bash有个flock的命令，perl里面好像也有一个 flock函数，就对应c语言的flock函数的吧。
https://perldoc.perl.org/functions/flock.html 官方的例子要把这行改为这样，或者像下面那样直接给出 use Fcntl qw(:flock SEEK_END LOCK_EX LOCK_UN);
sub lock {
my ($fh) = @_;
my $LOCK_EX = 2;
flock($fh, $LOCK_EX) or die "Cannot lock file - $!\n";
}
sub unlock {
my ($fh) = @_;
my $LOCK_UN = 8;
flock($fh, $LOCK_UN) or die "Cannot unlock file - $!\n";
}
open(my $config_lock, ">>", "/tmp/config.lock") or die "Can't open config.lock $!";
lock($config_lock);
unlock($config_lock);