RCMD(1)

RCMD(1) | 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 possible 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 complicated to explain here.

May 31, 2011 | NetBSD 9.5