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Shell account tutorial

2,040 bytes added, 05:43, 29 January 2013
Added troubleshooting and bash tips guide
The [[gp:Bradley Department of Electrical and Computer Engineering|ECE]] department offers shell ccounts on the [[gp:CAD and Visualization Laboratory|CVL]] for Virginia Tech affiliates. Accounts can be created at [http://computing.ece.vt.edu/accounts/ this page].
The ECE2524 VM (128.173.88.125) can be accessed via SSH for CVL users, and has tmux, mosh, and weechat installed. Acidburn (acidburn.vtluug.org), the VTLUUG shell server, has a few more IRC clients installed, as well as other software and full IPv6 support.The [[gp:CAD and Visualization Laboratory|CVL]] does ''not'' have any IRC clients installed, but is useful for general computing (e.g. MATLAB)
One advantage of a shell account is that it allows one to leave an IRC client constantly connected, eliminate join/quit spam, and log missed messages to check later. In order to accomplish this, the IRC client must be run inside either tmux or screen so that it will not be killed when you disconnect from SSH.
# Now detach from the tmux session to return to a terminal while leaving weechat running
#* <code>^b-d</code> (that is, press Control-b, then d)
#* ''Use this whenever you are inside a tmux window and wish to return to a shell''
# To, reattach to the first tmux seesion, just use <code>tmux a</code>
#* <code>user@ece2524:~$ tmux attach</code>. #* ''On subsequent logins, this should be the only command you need to execute to return to IRC''
Check out the [http://www.dayid.org/os/notes/tm.html tmux and screen cheat sheet] for a quick reference of some of the other tmux commands. An additional command that might be useful is <code>tmux list-sessions</code>. [http://mosh.mit.edu Mosh] is another helpful tool you may want to use for high-latency or mobile (e.g. wifi) connections.You also may want to look into zsh, an alternative to bash with more features. ==Random Bash tips==* Tab completion exists on lots of things in your shell. For example, try "cd /" and then "cd /home/<TAB>" and it will autocomplete. It also exists in weechat for users' nicks. * Man pages are a helpful way to get usage information on commands. For example, run "man mv" in a terminal for usage information on mv. You can use PgUp/PgDn to scroll. Inside a man page, you can search using the "/" key. For example, to search "mv" for "existing file", type "/existing file" and hit enter to highlight all occurances and jump to the first one.* Inside a terminal, the up and down arrows can be used to recall the previous and next commands respectively, to prevent retyping long commands if you make a mistake.* Ctrl-D is the universal "end-of-file" command, and can be used to logout of shells* Ctrl-C is the universal interrupt command, and can be used to kill running terminal jobs and clear your currently-typed command (rather than holding down backspace). ==Troubleshooting==If you get an error like "ssh_exchange_identification: Connection closed by remote host", a few things are likely:* Your username/password combination is incorrect* You (or someone using your IP address) have had too many failed login attempts, and fail2ban or a similar utility has banned you for a period of time, typically a week or so. ** This is easy to identify because ssh fails ''before'' you are prompted for a password.** If this happened on a CVL machine, try connecting to a different node like <code>ssh pid@cvl10.ece.vt.edu</code>
[[Category:IRC]]
[[Category:Tutorials]]
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