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locks(4)							     locks(4)



NAME

  locks	- A directory that contains lock files for communication devices and
  remote systems that prevent multiple attempts	to use the same	device or
  contact a remote system

SYNOPSIS

  /var/spool/locks

DESCRIPTION

  Lock files are created by the	uucico daemon, the cu command, the tip com-
  mand,	and the	uugetty	command	in the /var/spool/locks	directory. The files
  are created when the utility opens the serial	line for communication.

  The lock file	locks the device or remote system so that another process
  cannot access	it while it is in use. The file	name of	the lock file uses
  one of the following forms:

       LCK..device_name
       LCK..system_name

  Where	device_name is the name	of the device (such as ttyd0) and system_name
  is the name of the system (such as hera).

  Normally, the	process	that creates a lock file will remove it	when the pro-
  cess has finished using the line. However, it	is possible for	lock files to
  be left behind (for example: system crash, phone line	disconnects unexpect-
  edly). This situation	has been accounted for and the commands	that use lock
  files	can handle the situation and overwrite these files, if appropriate.

  Lock files contains the process ID (PID) of the process that created the
  lock.	 The lock file is a data file; to see its contents, use	the following
  command:

	od -d lockfile

  Where	lockfile is the	name of	the file. For example:

       % od -d /var/spool/locks/LCK..ttyd0

       0000000	06854 00000
       0000004

  In this example, the lock file (LCK..ttyd0) was created by the process with
  PID 6854.

FILES

  /usr/lib/uucp
	    Contains the uucico	daemon and uugetty program.

  /usr/bin  Contains the uucp, cu, and tip programs.

RELATED	INFORMATION

  Commands: cu(1), od(1), tip(1), uucp(1), uugetty(8)

  Daemons: uucico(8)