TLOGGER(8,C) AIX Commands Reference TLOGGER(8,C) ------------------------------------------------------------------------------- tlogger PURPOSE Writes data to a log file. SYNTAX +- -c /usr/adm/ras/tlogfile -+ /etc/tlogger ---| |---> +--------- -c file ----------+ +- -b /usr/adm/ras/tlogfile.bk -+ >---| |--- & ---| +----------- -b file -----------+ DESCRIPTION The terminal-logging daemon tlogger collects data read or written to its associated terminal and writes that data to a log file. Each time the daemon is started, the contents of the current log file replace the backup log file. A new current log file is created with permissions set to allow read and write by the owner. The associated terminal is identified in the following manner: Standard error is assumed to be the correct terminal if it is a terminal device ( isatty() returns true ). Otherwise, the process's usrinfo is used to identify the login terminal, and that device is used. The tlogger daemon creates a message queue, and passes that queue id to the associated terminal using the ioctl TCLOG system call. The daemon then loops waiting on message queue data; it writes any message queue data it receives to the end of the current log file. The terminal log daemon catches all signals (except SIGKILL). On receipt of a signal, the daemon issues an ioctl TCLOG to its associated terminal to turn off logging. This causes the terminal to stop sending log messages. The daemon then removes the message queue and exits. The daemon also terminates if it can no longer write to the log file due to file size constraints. In this case, an error message is written to standard error. The tlogger daemon should be started in the background either from /etc/rc, or from the command line. This starts the terminal sending its I/O data to the daemon. The tlog command can then be used to stop or restart the sending of terminal I/O to the daemon. The daemon itself may be terminated with the kill command, but would ordinarily continue to run until shutdown occurs. Processed November 8, 1990 TLOGGER(8,C) 1 TLOGGER(8,C) AIX Commands Reference TLOGGER(8,C) Notes: 1. SIGKILL should not be used to stop the daemon, since cleanup of system resources cannot be done in that case. 2. It may be necessary to prevent passwords from showing up in the terminal logs. You can prevent the system from logging passwords by having the getpass() subroutine turn off terminal logging while it is reading the password. The login, adduser, newgrp, and passwd commands use this subroutine. FLAGS -b file Specifies a file to be used as the backup log file. The default backup file is /usr/adm/ras/tlogfile.bk. -c file Specifies a file to be used as the current log file. The default current file is /usr/adm/ras/tlogfile. FILES /etc/rc System startup file. /usr/adm/ras/tlogfile Default current log file. /usr/adm/ras/tlogfile.bk Default backup log file. RELATED INFORMATION See the following commands: "shutdown" and "kill." See the ioctl system call and the getpass subroutine in AIX Operating System Technical Reference. Processed November 8, 1990 TLOGGER(8,C) 2