rcmd(1) [netbsd man page]
RCMD(1) BSD General Commands Manual RCMD(1) NAME
rcmd -- backend driver for rcmd(3) SYNOPSIS
rcmd [-46dn] [-l username] [-p port] [-u localusername] host command DESCRIPTION
rcmd executes command on host. rcmd copies its standard input to the remote command, the standard output of the remote command to its standard output, and the standard error of the remote command to its standard error. Interrupt, quit and terminate signals are propagated to the remote command; rcmd normally terminates when the remote command does. The options are as follows: -4 Use IPv4 addresses only. -6 Use IPv6 addresses only. -d The -d option turns on socket debugging (using setsockopt(2)) on the TCP sockets used for communication with the remote host. -l By default, the remote username is the same as the local username. The -l option allows the remote name to be specified. Another pos- sible way to specify the remote username is the notation user@host. -n The -n option redirects input from the special device /dev/null (see the BUGS section of this manual page). -p port Uses the given port instead of the one assigned to the service ``shell''. May be given either as symbolic name or as number. -u The -u option allows the local username to be specified. Only the superuser is allowed to use this option. Shell metacharacters which are not quoted are interpreted on local machine, while quoted metacharacters are interpreted on the remote machine. For example, the command rcmd otherhost cat remotefile >> localfile appends the remote file remotefile to the local file localfile, while rcmd otherhost cat remotefile ">>" other_remotefile appends remotefile to other_remotefile. FILES
/etc/hosts SEE ALSO
rsh(1), rcmd(3), environ(7) HISTORY
The rcmd command appeared in NetBSD 1.3 and is primarily derived from rsh(1). Its purpose was to create a backend driver for rcmd(3) that would allow the users of rcmd(3) to no longer require super-user privileges. BUGS
If you are using csh(1) and put a rcmd in the background without redirecting its input away from the terminal, it will block even if no reads are posted by the remote command. If no input is desired you should redirect the input of rcmd to /dev/null using the -n option. You cannot use rcmd to run an interactive command (like rogue(6) or vi(1)). Use rlogin(1) instead. The stop signal, SIGSTOP, will stop the local rcmd process only. This is arguably wrong, but currently hard to fix for reasons too compli- cated to explain here. BSD
May 31, 2011 BSD
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RSH() RSH() NAME
rsh - remote shell SYNOPSIS
rsh host [-l username] [-n] [-d] [-k realm] [-f | -F] [-x] [-PN | -PO] command DESCRIPTION
Rsh connects to the specified host, and executes the specified command. Rsh copies its standard input to the remote command, the standard output of the remote command to its standard output, and the standard error of the remote command to its standard error. This implementa- tion of rsh will accept any port for the standard error stream. Interrupt, quit and terminate signals are propagated to the remote com- mand; rsh normally terminates when the remote command does. Each user may have a private authorization list in a file .k5login in his login directory. Each line in this file should contain a Ker- beros principal name of the form principal/instance@realm. If there is a ~/.k5login file, then access is granted to the account if and only if the originater user is authenticated to one of the princiapls named in the ~/.k5login file. Otherwise, the originating user will be granted access to the account if and only if the authenticated principal name of the user can be mapped to the local account name using the aname -> lname mapping rules (see krb5_anadd(8) for more details). OPTIONS
-l username sets the remote username to username. Otherwise, the remote username will be the same as the local username. -x causes the network session traffic to be encrypted. -f cause nonforwardable Kerberos credentials to be forwarded to the remote machine for use by the specified command. They will be removed when command finishes. This option is mutually exclusive with the -F option. -F cause forwardable Kerberos credentials to be forwarded to the remote machine for use by the specified command. They will be removed when command finishes. This option is mutually exclusive with the -f option. -k realm causes rsh to obtain tickets for the remote host in realm instead of the remote host's realm as determined by krb_realmofhost(3). -d turns on socket debugging (via setsockopt(2)) on the TCP sockets used for communication with the remote host. -n redirects input from the special device /dev/null (see the BUGS section below). -PN -PO Explicitly request new or old version of the Kerberos ``rcmd'' protocol. The new protocol avoids many security problems found in the old one, but is not interoperable with older servers. (An "input/output error" and a closed connection is the most likely result of attempting this combination.) If neither option is specified, some simple heuristics are used to guess which to try. If you omit command, then instead of executing a single command, you will be logged in on the remote host using rlogin(1). Shell metacharacters which are not quoted are interpreted on the local machine, while quoted metacharacters are interpreted on the remote machine. Thus the command rsh otherhost cat remotefile >> localfile appends the remote file remotefile to the local file localfile, while rsh otherhost cat remotefile ">>" otherremotefile appends remotefile to otherremotefile. FILES
/etc/hosts ~/.k5login (on remote host) - file containing Kerberos principals that are allowed access. SEE ALSO
rlogin(1), kerberos(3), krb_sendauth(3), krb_realmofhost(3) BUGS
If you are using csh(1) and put a rsh(1) in the background without redirecting its input away from the terminal, it will block even if no reads are posted by the remote command. If no input is desired you should redirect the input of rsh to /dev/null using the -n option. You cannot run an interactive command (like rogue(6) or vi(1)); use rlogin(1). Stop signals stop the local rsh process only; this is arguably wrong, but currently hard to fix for reasons too complicated to explain here. RSH()