学步园

import os
import fcntl
import errno

def lock_file(filename):
    fd = os.open(filename, os.O_CREAT | os.O_WRONLY, 0666)
    try:
        fcntl.lockf(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
        return True
    except IOError, e:
        if e.errno in (errno.EACCES, errno.EAGAIN):
            return False

if not lock_file('/tmp/test.lock'):
  print "another instance is running"lock_file('/tmp/test.lock')

再附上一份perl的代码：

use Fcntl qw(:flock);

  my $lockdir = 'lock';
  if (!-d $lockdir) {
      mkdir $lockdir, 0755;
      my $status=$!;
      die "Failed to create $lockdir: $status/n" if (!-d $lockdir);
  }
  my $lockfile="$lockdir/test.pid";
  if (!open(PID, ">$lockfile")) {
    die "can not open pid file/n";
  }
  unless (flock(PID, LOCK_EX|LOCK_NB)) {
    die "can not lock pid file/n";
  }
  print "locked/n";