A/UX® System Administrator's Reference Sections 1M, 7, and 8

Start upShell (8) Start upShell (8)
variables.
The following variables are built into the NUX Startup shell:
PATH Specify the search path for commands (see
the section "Program Execution Environment"
below).
P S 1 Specify the prompt string, by default
"startup* ."
T z Specify the NUX time-zone variable (see
environ(5)).
HOME Specify the default argument (home directory)
for the cd and chdi r commands.
ROOT Specify the default argument (home root) for
the chroot command.
autorecovery Specify the command string for verifying the
integrity of the file system.
autolaunch Specify the command string for the kernel
launch program (see below).
cwd Specify the current working directory of the
shell.
cwroot Specify the current working root of the shell.
? Specify the exit status returned by the last
command executed.
The shell gives initial values to all the above variables. The
values persist across invocations of NUX Startup even if the variable
is not exported (see export in the section "Built-in Commands").
There is a limit on the number of variables that can exist.
The limit is normally 20, but can be changed by modifying a
resource.
Program Execution Environment
The shell interprets each line of input as a single command. The
first word in the command line is interpreted as the name of the
command to be executed.
If a command name matches one of the special commands built
into the shell (see the section "Built-in Commands"), it is executed
in the shell process. If the command name does not match a
special command, a search for a program of the same name occurs
in the search paths stored in the PATH variable.
February, 1990 3
Revision C