locks(4) [osf1 man page]
locks(4) Kernel Interfaces Manual 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 command, 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 sys- tem_name is the name of the system (such as hera). Normally, the process that creates a lock file will remove it when the process has finished using the line. However, it is possible for lock files to be left behind (for example: system crash, phone line disconnects unexpectedly). 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
Contains the uucico daemon and uugetty program. Contains the uucp, cu, and tip programs. RELATED INFORMATION
Commands: cu(1), od(1), tip(1), uucp(1), uugetty(8) Daemons: uucico(8) delim off locks(4)
Check Out this Related Man Page
uucico(8) System Manager's Manual uucico(8) NAME
uucico - Transfers uucp command, data, and execute files to remote systems SYNOPSIS
uucico [-r role_number] [-x debug_level] [-s system_name] FLAGS
The role_numbers are 1 for server mode and 0 (zero) for client mode. The default is 0 (zero). If uucico is started manually, set this flag to 1. Displays debugging information on the screen of the local terminal. The valid range for debug_level is 0 to 9. The higher the number, the more detailed the final report. This flag is useful in correcting problems with the expect_send sequence in the Systems file. The name of the remote system. Use only when starting uucico manually. The system_name is supplied internally when uucico is started automatically. Note that system names must contain only ASCII characters. DESCRIPTION
The uucico daemon transports uucp Command (C.*), Data (D.*), and Execute (E.*) files created by the uucp and uux commands to a specified remote system. Both the local and remote systems run the uucico daemon, and the two daemons communicate with each other to complete trans- fer requests. The uucico daemon performs the following actions: Scans the spooling directory (/usr/spool/uucp/system_name) on the local system for trans- fer requests. Selects the device used for the communications connection after checking the /usr/lib/uucp/Devices file and the lock files in the /var/spool/locks directory. Places a call to the specified remote system using information in the Systems, Dialers, and Dialcodes files located in the /usr/lib/uucp directory. Performs the required login sequence specified in the Systems file. Checks permissions listed in the /usr/lib/uucp/Permissions file. Checks scheduling limits in the Maxuuscheds and Maxuuxqts files located in the /usr/lib/uucp directory. Runs all transfer requests from both the local and the remote system, placing the transferred files in the public directories (/usr/spool/uucppublic/*). Logs transfer requests and completions in files in the /usr/spool/uucp/.Log/uucico directory. Notifies speci- fied users of transfer requests. Usually the uucico daemon is called by the uucp and uux commands when needed, and is started periodically by the uucp scheduling daemon, uusched, which is started by the cron daemon. The uucico daemon can be started from the command line for debugging. The uucp command uutry also starts uucico with debugging turned on. In the case of a uux command request for the execution of a command on a remote system, the uucico daemon transfers the files, and the uuxqt daemon executes the command on the remote system. ENVIRONMENT VARIABLES
The following environment variables affect the execution of uucico: Specifies the flow control used on the connection. Permitted values are: HW (hardware), SW (software), HSW (hardware and software), and NONE. The uugetty on the remote system must also use the same flow con- trol. Specifies the amount of time (in seconds) for uucico to try to establish a connection before it times out. A value of 0 (zero) indicates an unlimited amount of time. EXAMPLES
To start the uucico daemon from the command line as a background process and contact the remote system hera, enter: /usr/lib/uucp/uucico -r1 -shera & To debug uucico connections, start the uucico daemon with the -x flag, and enter: /usr/lib/uucp/uucico -r1 -svenus -x9 FILES
Specifies the command path The uucp configuration files Contains lock files that prevent multiple uses of devices and multiple calls to systems Contains all the configuration files for uucp Contains information about available devices Contains dial-code abbreviations Speci- fies initial handshaking on a link Limits scheduled jobs Limits remote command executions Describes access permissions for remote systems Describes accessible remote systems Lists uucico daemon errors that uucp cannot correct Contains uucico daemon log files Lists the last time a remote system was contacted and the minimum time until the next retry Contains C.*, D.*, and E.* files to be transferred by the uucico daemon Command files Data files Execute files Contains files after transfer by the uucico daemon RELATED INFORMATION
Commands: cron(8), uucp(1), uustat(1), uutry(1), uuto(1), uux(1) delim off uucico(8)