path: root/sshexec.1

.TH SSHEXEC 1 sshexec

.SH NAME
sshexec - run a command through ssh(1) with normal command syntax

.SH SYNOPSIS
.B sshexec
.RB [ {
.RI [\fBssh=\fP ssh-command ]
.RI [\fBdir=\fP directory ]
.RB [[\fIfd\fP]{ > , >> , >| , < , <> }[ & ] = \fIfile\fP]
.BR } ]
[ssh-option] ...\,
.I destination
.I command
.RI [ argument ]\ ...\,

.SH DESCRIPTION
The
.B sshexec
utility is a wrapper for SSH that makes it easy to run commands
directly in the SSH command.

.B sshexec
passes any argument after
.B }
to
.I ssh-command
.RB ( ssh
if not specified), and only modifies
.I command
.RB [ argument ]\ ...\,
and inserts extra arguments after
.I destination
(it may also add a
.B --
argument immediately before
.IR destination )
to cause the remote shell it change working directory to
.IR directory ,
if specified, and execute the provided
.I command
and
.IR argument s
as a regular command rather than as shell code joined
by together by spaces.

.SH OPTIONS
.B sshexec
options may be placed at the very beginning enclosed with
the arguments
.B {
and
.BR } .
.B sshexec
options, if any, shall be placed in the same
.B {
.BR } -group.
Any other option will be passed as is to the
.BR ssh (1)
utility or
.IR ssh-command .
The
.B sshexec
utility has a build it list of options recognised by the
.BR ssh (1)
utility and will not allow anything matching this list.
The
.B sshexec
utility does not allow mixing options and operands: no
option may be placed after
.IR destination ,
such options will be treated as the
.I command
or an
.IR argument .
.PP
The following
.B sshexec
options are supported:
.TP
.BI ssh= ssh-command
Instead of looking for
.B ssh
in
.IR PATH ,
the
.B sshexec
utility shall use
.IR ssh-command ,
which it will look for in
.I PATH
if it is only a file name (does not contain a slash
.RB ( / )).
.TP
.BI dir= directory
In the remote, change working directory to
.I directory
before executing
.IR command .
.TP
.IB \fR[\fPfd\fP]\fP >= file
After changing working directory (assuming one is specified),
create or truncate the specified
.I file
and open it for writing, using file descriptor number
.IR fd .
(Default
.I fd
is 1 (standard output).)
.TP
.IB \fR[\fPfd\fP]\fP >>= file
After changing working directory (assuming one is specified),
create the specified
.I file
if it does not exist and open it for writing in
append-mode, using file descriptor number
.IR fd .
(Default
.I fd
is 1 (standard output).)
.TP
.IB \fR[\fPfd\fP]\fP >|= file
After changing working directory (assuming one is specified),
create the specified
.IR file ,
but fail if it already exists, and open it for writing,
using file descriptor number
.IR fd .
(Default
.I fd
is 1 (standard output).)
.TP
.IB \fR[\fPfd\fP]\fP <= file
After changing working directory (assuming one is specified),
open the specified
.IR file ,
for reading, using file descriptor number
.IR fd .
(Default
.I fd
is 0 (standard input).)
.TP
.IB \fR[\fPfd\fP]\fP <>= file
After changing working directory (assuming one is specified),
open the specified
.IR file ,
for reading and writing, creating it if it does not
already exist, using file descriptor number
.IR fd .
(Default
.I fd
is 0 (standard input).)
.TP
.IB \fR[\fPfd\fP]\fP \fR{\fP>\fP,\fP>>\fP,\fP>|\fP}\fP&= file
Duplicate the file descriptor
.I fd
giving the new file descriptor the number
.IR file .
(Default
.I fd
is 1 (standard output).)
.TP
.IB \fR[\fPfd\fP]\fP \fR{\fP>\fP,\fP>>\fP,\fP>|\fP}\fP&=-
Close the file descriptor
.IR fd .
(Default
.I fd
is 1 (standard output).)
.TP
.IB \fR[\fPfd\fP]\fP \fR{\fP<\fP,\fP<>\fP}\fP&= file
Duplicate the file descriptor
.I fd
giving the new file descriptor the number
.IR file .
(Default
.I fd
is 0 (standard input).)
.TP
.IB \fR[\fPfd\fP]\fP \fR{\fP<\fP,\fP<>\fP}\fP&=-
Close the file descriptor
.IR fd .
(Default
.I fd
is 0 (standard input).)

.SH OPERANDS
The following operands are supported:
.TP
.I destination
This operand is passed as is (without validation) to the
.BR ssh (1)
utility. The
.BR ssh (1)
utility will expect it the be either in the form
.RI [ user\fP\fB@ ] hostname
or in the form
.BR ssh:// [\fIuser @ ]\fIhostname\fP[ : \fIport\fP].
.TP
.IR command \ [ argument ]\ ...\,
Whereas the
.BR ssh (1)
utility would simply join the
.I command
and
.I argument
arguments with a space between each of them as pass it
to the remote shell for execution, the
.B sshexec
utility forces the remote shell to treat each of the
as separate arguments and cause the shell to executing
them as a non-builtin command.

.SH STDIN
The
.B sshexec
utility itself does not use the standard input.

.SH INPUT FILES
None.

.SH ENVIRONMENT VARIABLES
The following environment variables affects the execution of
.BR sshexec :
.TP
.SH PATH
Default. See to the Base Definitions volume of POSIX.1-2017, Section 8.3, Other Environment Variables.
This environment variable affects where the
.B sshexec
utility can find the
.BR ssh (1)
utility or
.IR ssh-command .
.PP
Other environment variables may affect the execution of the
.BR ssh (1)
utility.

.SH ASYNCHRONOUS EVENTS
Default.

.SH STDOUT
The
.B sshexec
utility itself does not use the standard output.

.SH STDERR
The standard error is used for diagnostic messages in the
.B sshexec
utility itself.

.SH OUTPUT FILES
None.

.SH EXTENDED DESCRIPTION
None.

.SH EXIT STATUS
The
.B sshexec
utility exits with the exit status of the
.BR ssh (1)
utility or with 255 if an error occurred.

.SH CONSEQUENCES OF ERRORS
Default.

.SH APPLICATION USAGE
None.

.SH EXAMPLES
None.

.SH RATIONALE
None.

.SH NOTES
None.

.SH BUGS
The remote shell must be sufficiently similar to
.BR sh (1posix).
Namely, it must support the
.B cd
builtin command and the commands
.B exec
and
.B printf
is expected by POSIX. Additionally, it must support
.BR \(dq$(\ )\(dq ,
.BR \(aq\ \(aq ,
and
.BR && ,
and argument separation with the SP character.
The remote shell must also not treat any alphanumeric
character, underscore
.RB ( _ )
or slash
.RB ( / )
as special characters.

.SH FUTURE DIRECTIONS
None.

.SH SEE ALSO
.BR ssh (1)

.SH AUTHORS
Mattias Andrée
.RI < maandree@kth.se >