За что отвечает $TMOUT?

А что,

man bash

набрать сильно напрягает?

$ cat .bashrc
# User specific aliases and functions
alias ll='ls -A'
# Source global definitions
if [ -f /etc/bashrc ]; then
. /etc/bashrc
fi
Ну и что? Где в нем затрагиваеться
"If set to a value greater than zero, TMOUT is treated as the
default timeout for the read builtin. The select command termi-
nates if input does not arrive after TMOUT seconds when input is
coming from a terminal. In an interactive shell, the value is
interpreted as the number of seconds to wait for input after
issuing the primary prompt. Bash terminates after waiting for
that number of seconds if input does not arrive."?
?