Author: Zachary Lund

Your own personal man directory

Recently, I wanted to install a program in my home bin directory, and it had a man page to go with it. I started looking for a way to create my own personal man directory. According to the manual page for man, “man uses a sophisticated method of finding manual page files.” Indeed it does. It turns out that all I had to do was create a man directory inside of my home directory and man would know it was there:

zac@dakara:~$ manpath 
/usr/local/man:/usr/local/share/man:/usr/share/man
zac@dakara:~$ mkdir man
zac@dakara:~$ manpath 
/home/zac/man:/usr/local/man:/usr/local/share/man:/usr/share/man

Then to install the man page, I simply had to create the appropriate directory structure and copy the man page in:

zac@dakara:~$ mkdir -p man/en/man1/

Add an SSH Key to an SSH Agent on a Different Machine

I recently discovered that I can add an SSH key to an SSH agent on a different machine. I find this useful because I am very protective of my SSH keys and prefer to keep them on my desktop (Dakara) and not on my laptop (Adria).

On Adria, you can see that I have no keys added:

zac@adria:~$ ssh-add -l
The agent has no identities.

I then secure shell to Dakara and forward my agent (-A) from Adria. I still have no keys added:

zac@adria:~$ ssh dakara -A
zac@dakara's password:
No mail.
Last login: Mon Feb  9 17:30:49 2009 from adria.lund
zac@dakara:~$ ssh-add -l
The agent has no identities.

Next, I add a key from Dakara to my agent on Adria:

zac@dakara:~$ ssh-add
Enter passphrase for /home/zac/.ssh/id_dsa:
Identity added: /home/zac/.ssh/id_dsa (/home/zac/.ssh/id_dsa)
zac@dakara:~$ ssh-add -l
2048 27:81:f8:7f:38:75:6b:ce:95:e4:46:62:02:9c:84:bd /home/zac/.ssh/id_dsa (DSA)

When I log out of Dakara, the key is still available on Adria:

zac@dakara:~$ logout
Connection to dakara closed.
zac@adria:~$ ssh-add -l
2048 27:81:f8:7f:38:75:6b:ce:95:e4:46:62:02:9c:84:bd /home/zac/.ssh/id_dsa (DSA)

Now my key is available on Adria without ever being on Adria. Even with physical access to my laptop, it would take a sophisticated hacker to steal my SSH key.