When you work in a distributed environment then you need to communicate with remote users and you also need to access remote Unix machines.
There are several Unix utilities which are especially useful for users computing in a networked, distributed environment. This tutorial lists few of them −
The ping Utility
The ping command sends an echo request to a host available on the network. Using this command you can check if your remote host is responding well or not.
The ping command is useful for the following −
- Tracking and isolating hardware and software problems.
- Determining the status of the network and various foreign hosts.
- Testing, measuring, and managing networks.
Syntax
Following is the simple syntax to use ping command −
$ping hostname or ip-address
Above command would start printing a response after every second. To come out of the command you can terminate it by pressing CNTRL + C keys.
Example
Following is the example to check the availability of a host available on the network −
$ping google.com PING google.com (74.125.67.100) 56(84) bytes of data. 64 bytes from 74.125.67.100: icmp_seq=1 ttl=54 time=39.4 ms 64 bytes from 74.125.67.100: icmp_seq=2 ttl=54 time=39.9 ms 64 bytes from 74.125.67.100: icmp_seq=3 ttl=54 time=39.3 ms 64 bytes from 74.125.67.100: icmp_seq=4 ttl=54 time=39.1 ms 64 bytes from 74.125.67.100: icmp_seq=5 ttl=54 time=38.8 ms --- google.com ping statistics --- 22 packets transmitted, 22 received, 0% packet loss, time 21017ms rtt min/avg/max/mdev = 38.867/39.334/39.900/0.396 ms $
If a host does not exist then it would behave something like this −
$ping giiiiiigle.com ping: unknown host giiiiigle.com $
The ftp Utility
Here ftp stands for File Transfer Protocol. This utility helps you to upload and download your file from one computer to another computer.
The ftp utility has its own set of UNIX like commands which allow you to perform tasks such as −
- Connect and login to a remote host.
- Navigate directories.
- List directory contents
- Put and get files
- Transfer files as ascii, ebcdic or binary
Syntax
Following is the simple syntax to use ping command −
$ftp hostname or ip-address
Above command would prompt you for login ID and password. Once you are authenticated, you would have access on the home directory of the login account and you would be able to perform various commands.
Few of the useful commands are listed below −
| Command | Description |
|---|---|
| put filename | Upload filename from local machine to remote machine. |
| get filename | Download filename from remote machine to local machine. |
| mput file list | Upload more than one files from local machine to remote machine. |
| mget file list | Download more than one files from remote machine to local machine. |
| prompt off | Turns prompt off, by default you would be prompted to upload or download movies using mput or mget commands. |
| prompt on | Turns prompt on. |
| dir | List all the files available in the current directory of remote machine. |
| cd dirname | Change directory to dirname on remote machine. |
| lcd dirname | Change directory to dirname on local machine. |
| quit | Logout from the current login. |
It should be noted that all the files would be downloaded or uploaded to or from current directories. If you want to upload your files in a particular directory then first you change to that directory and then upload required files.
Example
Following is the example to show few commands −
$ftp amrood.com Connected to amrood.com. 220 amrood.com FTP server (Ver 4.9 Thu Sep 2 20:35:07 CDT 2009) Name (amrood.com:amrood): amrood 331 Password required for amrood. Password: 230 User amrood logged in. ftp> dir 200 PORT command successful. 150 Opening data connection for /bin/ls. total 1464 drwxr-sr-x 3 amrood group 1024 Mar 11 20:04 Mail drwxr-sr-x 2 amrood group 1536 Mar 3 18:07 Misc drwxr-sr-x 5 amrood group 512 Dec 7 10:59 OldStuff drwxr-sr-x 2 amrood group 1024 Mar 11 15:24 bin drwxr-sr-x 5 amrood group 3072 Mar 13 16:10 mpl -rw-r--r-- 1 amrood group 209671 Mar 15 10:57 myfile.out drwxr-sr-x 3 amrood group 512 Jan 5 13:32 public drwxr-sr-x 3 amrood group 512 Feb 10 10:17 pvm3 226 Transfer complete. ftp> cd mpl 250 CWD command successful. ftp> dir 200 PORT command successful. 150 Opening data connection for /bin/ls. total 7320 -rw-r--r-- 1 amrood group 1630 Aug 8 1994 dboard.f -rw-r----- 1 amrood group 4340 Jul 17 1994 vttest.c -rwxr-xr-x 1 amrood group 525574 Feb 15 11:52 wave_shift -rw-r--r-- 1 amrood group 1648 Aug 5 1994 wide.list -rwxr-xr-x 1 amrood group 4019 Feb 14 16:26 fix.c 226 Transfer complete. ftp> get wave_shift 200 PORT command successful. 150 Opening data connection for wave_shift (525574 bytes). 226 Transfer complete. 528454 bytes received in 1.296 seconds (398.1 Kbytes/s) ftp> quit 221 Goodbye. $
The telnet Utility
Many times you would be in need to connect to a remote Unix machine and work on that machine remotely. Telnet is a utility that allows a computer user at one site to make a connection, login and then conduct work on a computer at another site.
Once you are login using telnet, you can perform all the activities on your remotely connect machine. Here is example telnet session −
C:>telnet amrood.com Trying... Connected to amrood.com. Escape character is '^]'. login: amrood amrood's Password: ***************************************************** * * * * * WELCOME TO AMROOD.COM * * * * * ***************************************************** Last unsuccessful login: Fri Mar 3 12:01:09 IST 2009 Last login: Wed Mar 8 18:33:27 IST 2009 on pts/10 { do your work } $ logout Connection closed. C:>
The finger Utility
The finger command displays information about users on a given host. The host can be either local or remote.
Finger may be disabled on other systems for security reasons.
Following are the simple syntax to use finger command −
Check all the logged in users on local machine as follows −
$ finger Login Name Tty Idle Login Time Office amrood pts/0 Jun 25 08:03 (62.61.164.115)
Get information about a specific user available on local machine −
$ finger amrood Login: amrood Name: (null) Directory: /home/amrood Shell: /bin/bash On since Thu Jun 25 08:03 (MST) on pts/0 from 62.61.164.115 No mail. No Plan.
Check all the logged in users on remote machine as follows −
$ finger @avtar.com Login Name Tty Idle Login Time Office amrood pts/0 Jun 25 08:03 (62.61.164.115)
Get information about a specific user available on remote machine −
$ finger amrood@avtar.com Login: amrood Name: (null) Directory: /home/amrood Shell: /bin/bash On since Thu Jun 25 08:03 (MST) on pts/0 from 62.61.164.115 No mail. No Plan.
