May 2005
Intermediate to advanced
666 pages
21h 5m
English
book
SSH, The Secure Shell: The Definitive Guide, 2nd Edition
by Daniel J. Barrett, Richard E. Silverman, Robert G. Byrnes
Content preview from SSH, The Secure Shell: The Definitive Guide, 2nd EditionBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
The User rc File
The shell script /etc/ssh/sshrc is invoked by the SSH server for each incoming SSH connection. [5.6.3] You may define a similar script in your account, ~/.ssh/rc (OpenSSH) or ~/.ssh2/rc (Tectia), to be invoked for every SSH connection to your account. If this file exists, /etc/ssh/sshrc isn’t run.
The SSH rc file is much like a shell startup file (e.g., ~/.profile or ~/.cshrc), but it executes only when your account is accessed by SSH. It is run for both interactive logins and remote commands. Place any commands in this script that you would like executed when your account is accessed by SSH, rather than an ordinary login. For example, you can run and load your ssh-agent in this file:
# ~/.ssh/rc, assuming your login shell is the C shell
if ( ! $?SSH_AUTH_SOCK ) then
eval `ssh-agent`
/usr/bin/tty | grep 'not a tty' > /dev/null
if ( ! $status ) then
ssh-add
endif
endifLike /etc/ssh/sshrc, your personal rc file is executed just before the shell or remote command requested by the incoming connection. OpenSSH always uses the Bourne shell (/bin/sh) for ~/.ssh/rc, as it does for /etc/ssh/sshrc. In contrast, Tectia uses your login shell for ~/.ssh2/rc, unlike /etc/ssh2/sshrc.
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.