SSH Tricks

The most magical command he didn't mention is 'ssh-copy-id'. If you can log-in to a host with password, you just 'ssh-copy-id myuser@thishost', supply the password once, and from that moment you can ssh with public key authentication. Extreme magic.<p>Also, sshfs works great, but has some issues with memory mapped files that silently lose writes. Luckily (?) most programs don't use mmap to write files, so it's not very noticeable.<p>All in all, ssh is one of the greatest tools.

&#62; /dev/null .known_hosts<p>This is <i>not</i> a good idea (and far from "awesome"). I get why he's doing it, but suggesting that weakening the security of a tool that is meant to <i>enhance</i> it is bad advice.

Another handy trick: put this script on your path somewhere, and name it "ssh-argv0":<p><pre><code> #!/bin/sh exec ssh "${0##*/}" "$@" </code></pre> Then create symlinks to ssh-argv0 for common hostnames you ssh to, shortened using host aliases as suggested in the article. You now have a command for each host, which you can use as a prefix like sudo to run a single command on that host. For instance, "myth sudo reboot".<p>If you're used to using "ssh user@box foo", and not always for the same user (in which case you could use "User" in .ssh/config), you can do the same thing via "box -l user foo"

The ssh escape sequence "~" (without quotes) comes in handy at times.<p><pre><code> "~ C" Gives you a ssh command prompt. Press ? for help. "~ ." Closes the ssh connection; useful for unresponsive ssh connections!</code></pre>

Ok, not techically part of SSH itself but I think SShuttle[1] is one of the most awesome SSH tricks around.<p>[1] <a href="https://github.com/apenwarr/sshuttle" rel="nofollow">https://github.com/apenwarr/sshuttle</a>

I hadn't known about sshfs - that sounds great and I'll have to look it up.<p>One of my favorite features is ssh forced commands, <a href="http://oreilly.com/catalog/sshtdg/chapter/ch08.html#22858" rel="nofollow">http://oreilly.com/catalog/sshtdg/chapter/ch08.html#22858</a> which I use on infrequently used remote servers to present menus of pre-defined commands to me or to others. And at other times, I can use it to kick off a daemon on a remote server just by ssh'ing to that remote server with the proper key.<p>It's a simple way to create a "compile server" and then use one command line from my preferred machine to tell the compile server to check a certain directory and compile everything within it.<p>Yeah, ssh is nice.

Another trick I especially like is to use the command="" syntax inside of an authorized_keys file to allow a user to execute certain commands via ssh, especially handy for git-shell.

Anyone know how to ensure 8 bits worth of keyboard are passed? (Run emacs over ssh and you sometimes get stuck without the meta key working.)

I have a lot of machines I regularly connect to. Parsing the known_hosts file and adding to my shell's tab completion was a nice timesaver. Here's the line from my .bash_profile<p>complete -W "$(echo `cat ~/.ssh/known_hosts | cut -f 1 -d ' ' | sed -e s/,.*//g | uniq | grep -v "\["`;)" ssh

I'm not sure how this could omit "ssh -D".<p>Also, is it just me, or might his ssh-reagent bash function add keys to some other user's ssh agent process if they've sufficiently modified the permissions on their socket file in the temporary directory to allow you to write to it?

many shells can be setup to autocomplete a list of hosts parsed from ~/.ssh/known_hosts.<p>for tcsh, see <a href="http://www.opensource.apple.com/source/tcsh/tcsh-63.1/tcsh/complete.tcsh" rel="nofollow">http://www.opensource.apple.com/source/tcsh/tcsh-63.1/tcsh/c...</a>

I use SuperPutty on my Windows PC to manage many putty sessions at a time...it is a little clunky, however it is better than having putty open 5 or 10 times.

my personal favorite, a one liner to set up an email tunnel on a non-privileged port:<p>ssh -f username@mymailserver.com -L 2000:mymailserver.com:25 -N

<a href="http://www.funtoo.org/wiki/Keychain" rel="nofollow">http://www.funtoo.org/wiki/Keychain</a> is also quite nice.

+1 for sshfs, which comes in handy for backing up my hard drive to an external machine.

In case the article's author stops by:<p>- loose rhymes with "goose". The word is "lose".

gpg-agent. ;-)

Nice use of /tmp, I hope you're the only one on your machine.