You can lock your terminal with the lock command. The lock command requests a password from the user, reads it, and requests the password a second time to verify it. In the interim, the command locks the terminal and does not relinquish it until the password is received the second time. The timeout default value is 15 minutes, but this can be changed with the -Number flag.
Note: If your interface is AIXwindows use the xlock command in the same manner.
For example, to lock your terminal under password control, type:
lock
Press Enter.
You are prompted for the password twice so the system can verify it. If the password is not repeated within 15 minutes, the command times out.
For example, to reserve a terminal under password control, with a timeout interval of 10 minutes, type:
lock -10
Press Enter.
See the lock or the xlock command in the AIX 5L Version 5.1 Commands Reference for the exact syntax.