.TH CPU 1.SH NAMEcpu \- connection to CPU server.SH SYNOPSIS.B cpu[.B -h.I server] [.B -u.I user] [.B -a.I auth-method] [.B -P.I patternfile] [.B -e.I encryption-hash-algs] [.B -k.I keypattern] [.B -c.I cmd args ...].PP.B cpu[.B -R|.B -O].SH DESCRIPTION.I Cpustarts an.IR rc (1)running on the.I servermachine, or the machine named in the.B $cpuenvironment variable if there is no.B -hoption..IR Rc 'sstandard input, output, and error files will be.B /dev/consin the name space where the.I cpucommand was invoked.Normally,.I cpuis run in an.IR rio (1)window on a terminal, so.IR rcoutput goes to that window, and input comes from the keyboardwhen that window is current..IR Rc 'scurrent directory isthe working directory of the.I cpucommand itself..PPThe name space for the new.I rcis an analogue of the name space where the.I cpucommand was invoked:it is the same except for architecture-dependent bindings such as.B /binand the use of fast paths to file servers, if available..PPIf a.B -uargument is present,.I cpuuses the argument as the remote user id..PPIf a.B -cargument is present, the remainder of the command line is executed by.I rcon the server, and then.I cpuexits..PPIf a.B -Pargument is present, the.I patternfileis passed to.IR exportfs (4)to control how much of the local name space will be exported tothe remote system..PPThe.B -acommand allows the user to specify the authentication mechanism usedwhen connecting to the remote system.  The two possibilities for.I auth-methodare:.TF netkey.TP.B p9This is the default.  Authentication is done using the standard Plan 9mechanisms, (see.IR authsrv (6)).No user interaction is required..TP.B netkeyAuthentication is done using challenge/response and a hand heldauthenticator or the.I netkeyprogram(see.IR passwd (1)).The user must encrypt the challenge and type the encryptionback to.IR cpu .This is used if the local host is in a different protection domain thanthe server or if the user wants to log into the server as a differentuser..PD.PPThe.B -eoption specifies an encryption and/or hash algorithm touse for the connection.  If both are specified, they mustbe space separated and comprise a single argument, so theymust be quoted if in a shell command.  The default is.L rc4_256encryption and.L sha1hashing.  See.IR ssl (3)for details on possible algorithms.  The argument.L clearspecifies no encryption algorithm and can be used to talkto older versions of the.I cpuservice..PPThe.B -kflag specifies a key pattern to use to restrict the keysselected by the.I auth_proxycall used for authentication..PPThe name space is built by running.B /usr/$user/lib/profilewith the root of the invoking name space bound to.BR /mnt/term .The.B serviceenvironment variable is set to.BR cpu ;the.B cputypeand.B objtypeenvironment variables reflect the server's architecture..PPThe.B -Rflag causes.I cputo run the server (remote) side of the protocol.It is run from service files such as.BR /bin/service/tcp17010 .The.B -Oflag is similar but simulates the pre-9P2000 versionof the .I cpuprotocol..SH FILESThe name space of the terminal side of the.I cpucommand is mounted, via.IR exportfs (4),on the CPU side on directory.BR /mnt/term .The files such as.B /dev/consare bound to their standard locations from there..SH SOURCE.B /sys/src/cmd/cpu.c.SH SEE ALSO.IR rc (1) ,.IR rio (1) ,.IR exportfs (4).SH BUGSBinds and mounts done after the terminal.B lib/profileis run are not reflected in the new name space..PPWhen using the.B -aoption to `log in' as another user, be aware thatresources in the local name space will be madeavailable to that user.