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Discussion using none toembed none with web,windows application bar code Examples split $ split /usr/share none for none /dict/words $ wc -l * 1000 xaa 1000 xab 1000 xac ...

1000 xdt 569 xdu 98569 total . The next example u ses the prefix argument to specify a filename prefix of SEC and uses c ( suffix-length) to change the number of letters in the filename suffix to 3:. $ split $ ls SECaa none none a SECaab ...

SECaaj -a 3 /usr/share/dict/words SEC SECaak SECaal SECaat SECaau SECaav SECabd SECabe SECabf SECabn SECabo SECabp SECabx SECaby SECabz SECach SECaci SECacj SECacr SECacs SECact SECadb SECadc SECadd SECadl SECadm SECadn. 828 ssh Securely executes commands on a remote system ssh [option] [user @]host [command-line] The ssh utility logs in on a remote system and starts a shell. Optionally, ssh executes a command on the remote system and logs off. The ssh utility, which can replace rsh and rlogin, provides secure, encrypted communication between two systems over an unsecure network.

. Arguments The host is the sy stem you want to log in or run a command on. Unless you have one of several kinds of authentication established, ssh prompts you for a username and password for the remote system. When ssh is able to log in automatically, it logs in as the user running the ssh command or as user if you specify user@ on the ssh command line.

The command-line runs on the remote system. Without command-line, ssh logs in on the remote system. You must quote special characters in command-line if you do not want the local shell to expand them.

. Options f (not foreground ) Sends ssh to the background after asking for a password and before executing command-line. This option is useful when you want to run the command-line in the background but must supply a password. Its use implies n.

l user (login) Attempts to log in as user. This option is equivalent to using user@ on the command line. n (null) Redirects standard input to ssh to come from /dev/null.

See f. p port Connects to port port on the remote system. Be aware that scp uses (uppercase) P to specify a port.

q (quiet) Suppresses warning and diagnostic messages. t (tty) Allocates a pseudo-tty to the ssh process on the remote system. Without this option, when you run a command on a remote system, ssh does not allocate a tty (terminal) to the process.

Instead, ssh attaches standard input and standard output of the remote process to the ssh session that is normally, but not always, what you want. This option forces ssh to allocate a tty on the remote system so programs that require a tty will work. v (verbose) Displays debugging messages about the connection and transfer.

This option is useful if things are not going as expected.. ssh 829 X (X11) Turns on X11 forwarding. You may not need this option X11 forwarding may be turned on in a configuration file. x (X11) Turns off X11 forwarding.

. Discussion OpenSSH Using public key e none for none ncryption, OpenSSH provides two levels of authentication: server and client/user. First the client verifies that it is connected to the correct server. Then OpenSSH encrypts communication between the systems.

Once a secure, encrypted connection has been established, OpenSSH makes sure the user is authorized to log in on or copy files to and from the server. After verifying the system and user, OpenSSH can allow various services to pass through the connection, including interactive shell sessions (ssh), remote command execution (ssh), file copying (scp), FTP services (sftp), X11 client/server connections, and TCP/IP port tunneling. The ssh utility allows you to log in on a remote system over a network.

For example, you might choose to use a remote system to access a special-purpose application or to take advantage of a device that is available only on that system, or you might use a remote system because you know it is faster or less busy than the local system. While they are traveling, many businesspeople use ssh on a laptop to log in on a system at company headquarters. From a GUI you can use several systems simultaneously by logging in on each one from a different terminal emulator window.

With trusted X11 forwarding turned on, it is a simple matter to run an X11 program over an ssh connection: Run ssh from a terminal emulator running on an X11 server and give an X11 command such as xclock; the graphical output appears on the local display. To turn on trusted X11 forwarding, set ForwardX11Trusted to yes in the /etc/ssh/ssh_config configuration file. To increase security (and in some cases reduce usability) set ForwardX11Trusted to no.

Two files list the hosts the local system has connected to and positively identified: ~/.ssh/known_hosts (user) and /etc/ssh/ssh_known_hosts (global). No one except the owner (a user working with root privileges in the case of the second file) should be able to write to either of these files.

No one except the owner should have any access to a ~/.ssh directory. When you connect to an OpenSSH server for the first time, the OpenSSH client prompts you to confirm you are connected to the right system.

This check can help prevent a man-in-the-middle attack:. The authenticity o f host "plum (192.168.0.

10)" can"t be established. RSA key fingerprint is d1:9d:1b:5b:97:5c:80:e9:4b:41:9a:b7:bc:1a:ea:a1. Are you sure you want to continue connecting (yes/no) yes Warning: Permanently added "plum,192.

168.0.10" (RSA) to the list of known hosts.

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