After reading just the ssh(1) man page and the usage abstract, some poor
soul may think that the "command" argument to ssh may be either a simple
command or executable path that will be directly passed to execvp().
Even if he doesn't depend on any extra arguments being either used or
ignored, he may be bitten by paths with spaces, or by a login shell that
is not /bin/sh-like.
Better document the whole thing as it stands; a lot of scripts already
depend on the current behaviour, so it's not realistic to expect
it to ever change.
Index: usr.bin/ssh/ssh.1
===================================================================
RCS file: /cvs/src/usr.bin/ssh/ssh.1,v
retrieving revision 1.371
diff -u -r1.371 ssh.1
--- usr.bin/ssh/ssh.1 4 May 2016 12:21:53 -0000 1.371
+++ usr.bin/ssh/ssh.1 1 Jun 2016 06:59:46 -0000
@@ -64,7 +64,7 @@
.Op Fl W Ar host : Ns Ar port
.Op Fl w Ar local_tun Ns Op : Ns Ar remote_tun
.Oo Ar user Ns @ Oc Ns Ar hostname
-.Op Ar command
+.Op Ar command Op Ar args ...
.Ek
.Sh DESCRIPTION
.Nm
@@ -88,8 +88,12 @@
.Pp
If
.Ar command
-is specified,
-it is executed on the remote host instead of a login shell.
+is specified, it is joined by spaces with any extra
+.Ar args
+into a command string that
+will be executed via the
+.Fl c
+option of the remote user's login shell instead of an interactive session.
.Pp
The options are as follows:
.Pp
@@ -966,9 +970,8 @@
host key is not known or has changed.
.Pp
When the user's identity has been accepted by the server, the server
-either executes the given command in a non-interactive session or,
-if no command has been specified, logs into the machine and gives
-the user a normal shell as an interactive session.
+logs into the machine and uses the remote user's login shell to run
+an interactive session or the given command.
All communication with
the remote command or shell will be automatically encrypted.
.Pp
Index: usr.bin/ssh/ssh.c
===================================================================
RCS file: /cvs/src/usr.bin/ssh/ssh.c,v
retrieving revision 1.440
diff -u -r1.440 ssh.c
--- usr.bin/ssh/ssh.c 4 May 2016 14:29:58 -0000 1.440
+++ usr.bin/ssh/ssh.c 1 Jun 2016 06:59:46 -0000
@@ -190,7 +190,7 @@
" [-F configfile] [-I pkcs11] [-i identity_file] [-L address]\n"
" [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
" [-Q query_option] [-R address] [-S ctl_path] [-W host:port]\n"
-" [-w local_tun[:remote_tun]] [user@]hostname [command]\n"
+" [-w local_tun[:remote_tun]] [user@]hostname [command [args ...]]\n"
);
exit(255);
}
