ch14.htm

linux-unix130.linux.and.unix.ebooks130 linux and unix ebookslinuxLearning Linux - Collection of 12 E

a sample FTP session and follow the steps for finding and getting software from a

remote site.</P>

<P><TT>ftp</TT> is the user interface to the ARPANET standard FTP. The <TT>ftp</TT>

service is the interface to the file transfer protocol. It lets a user connect to

another site and send and receive files.</P>

<P>In this section you will try to get a file from the address <TT>tsx-11.mit.edu</TT>

by logging in as anonymous. This anonymous use of FTP is very convenient and provides

access to innumerable servers, providing a wealth of information. Publicly accessible

FTP servers are called anonymous FTP servers.

<CENTER>

<H4><A NAME="Heading38<FONT COLOR="#000077">Anonymous FTP</FONT></H4>

</CENTER>

<P>Anonymous FTP enables users to access remote sites without having an authorized

user ID and password. Generally the login ID is <TT>anonymous</TT> and the password

is <TT>guest</TT>. Most current systems require your e-mail address as the password

instead of <TT>guest</TT>.



<DL>

	<DT></DT>

</DL>





<DL>

	<DD>

<HR>

<A NAME="Heading39<FONT COLOR="#000077"><B>TIP:</B> </FONT>FTP stands for File

	Transfer Protocol; <TT>ftp</TT> is the program you run on Linux.

<HR>



</DL>



<P>The client host with which <TT>ftp</TT> is to communicate may be specified on

the command line. If this is done, <TT>ftp</TT> immediately attempts to establish

a connection to an FTP server on that host. Otherwise, <TT>ftp</TT> enters its command

interpreter and awaits instructions from the user. When <TT>ftp</TT> is awaiting

commands from the user, the prompt <TT>ftp&gt;</TT> is provided to the user. Enter

<TT>ftp</TT> at the prompt, along with the site address:<FONT COLOR="#0066FF"></FONT>

<PRE><FONT COLOR="#0066FF">$ ftp hostname

</FONT></PRE>

<P>A hostname can be either a hostname or an Internet address. For example, you can

use the following Internet address:<FONT COLOR="#0066FF"></FONT>

<PRE><FONT COLOR="#0066FF">mpsi$ ftp tsx-11.mit.edu

</FONT></PRE>

<P>If your system connects to the MIT server, the text shown in Listing 14.10 appears.

<CENTER>

<H3><A NAME="Heading40<FONT COLOR="#000077">Listing 14.10. An ftp session.</FONT></H3>

</CENTER>

<PRE><FONT COLOR="#0066FF">

220 tsx-11 FTP server (Version wu-2.4(3) Mon Jun 5 16:40:22 EDT 1995) ready.

Name (tsx-11.mit.edu:uzma): anonymous

331 Guest login ok, send your complete e-mail address as password.

Password:

230-Welcome, archive user!  This is an experimental FTP server.  If you have any

230-unusual problems, please report them via e-mail to [e-mail].

230-If you do have problems, please try using a dash (-) as the first character

230-of your password -- this will turn off the continuation messages that may

230-be confusing your ftp client.

230-

230-The Linux archives are in /pub/linux/

230-

230-In most places, `get &lt;directory&gt;.tar' will retrieve a tar file containing

230-that directory.  `get &lt;file&gt;.gz' gets a gzipped version of the files, and

230-`get &lt;file&gt;.Z' gets a compressed version of the file.  `get &lt;dir&gt;.tar.gz'

230-is possible, but not recommended.  `get &lt;dir&gt;.zip' will get a zip archive

230-with *NO* compression of the directory &lt;dir&gt;.

230-

230-If you find something on TSX-11 which doesn't work, or which you

230-believe is obsolete, please send mail to [e-mail].

230-INCLUDE THE FULL PATHNAME OF THE FILE AND WHY YOU THINK IT IS OBSOLETE.

230-

230-                                    - Ted and Michael

230-

230 Guest login ok, access restrictions apply.

Remote system type is UNIX.

Using binary mode to transfer files.

ftp&gt;

</FONT></PRE>

<P>The first line confirms that the connection is established. Line 220 indicates

that the FTP server is ready. The system then prompts for a name, which is <TT>anonymous</TT>

in this case, and a password. The password is not echoed, so any typing mistakes

you make are not apparent. You are then connected to the remote FTP server, which

awaits your commands. ftp Commands The <TT>ftp</TT> service enables the user to execute

several commands. Some of the local commands are listed in Table 14.3. <BR>



<CENTER>

<P><FONT SIZE="4">Table 14.3. Some ftp commands. </FONT>

<TABLE BORDER="0">

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><I>Command </I></TD>

		<TD ALIGN="LEFT"><I>Description </I></TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>[account [</TT>passwd<TT>]]</TT> </TD>

		<TD ALIGN="LEFT">Provides a supplemental password required by a remote system for access to resources

			once a login has been successfully completed. If no argument is included, the user

			is prompted for an account password in a non-echoing input mode. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>ascii</TT> </TD>

		<TD ALIGN="LEFT">Sets the file transfer type to network ASCII. This is the default type. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>bell</TT> </TD>

		<TD ALIGN="LEFT">Sounds a bell after each file transfer. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>binary</TT> </TD>

		<TD ALIGN="LEFT">Sets the file transfer type to binary mode. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>bye</TT> </TD>

		<TD ALIGN="LEFT">Terminates the FTP session with the remote server and then exits. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>cd </TT>remote-directory </TD>

		<TD ALIGN="LEFT">Changes the working directory on the remote machine to the remote directory. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>cdup</TT> </TD>

		<TD ALIGN="LEFT">Goes to the parent of the current remote machine's working directory. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>chmod </TT>mode file-name </TD>

		<TD ALIGN="LEFT">Changes the permission modes of the file. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>close</TT> </TD>

		<TD ALIGN="LEFT">Terminates the FTP session with the remote server. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>delete </TT>remote-file </TD>

		<TD ALIGN="LEFT">Deletes the remote file on the remote machine. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>dir [</TT>remote-directory<TT>]</TT> </TD>

		<TD ALIGN="LEFT">Prints a listing of the remote directory to the terminal. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>disconnect</TT> </TD>

		<TD ALIGN="LEFT">Same as <TT>close</TT>. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>get </TT>remote-file </TD>

		<TD ALIGN="LEFT">Retrieves the remote file and stores it on the local ma- </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>[</TT>local-file<TT>]</TT> </TD>

		<TD ALIGN="LEFT">chine. If the local filename is not specified, it is given the same name it </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT">			<P>

		</TD>

		<TD ALIGN="LEFT">has on the remote machine. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>hash</TT> </TD>

		<TD ALIGN="LEFT">While a file is being transferred, the hash sign (#) is printed for each data block

			transferred. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>help [</TT>command<TT>]</TT> </TD>

		<TD ALIGN="LEFT">Prints an informative message about the meaning of the command. If no argument is

			given, <TT>ftp</TT> prints a list of the known commands. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>lcd [</TT>directory<TT>]</TT> </TD>

		<TD ALIGN="LEFT">Changes the working directory on the local machine. If no directory is specified,

			the user's home directory is used. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>ls [</TT>remote-directory<TT>]</TT> </TD>

		<TD ALIGN="LEFT">Lists the contents of the remote directory. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>mdelete [</TT>remote-files<TT>]</TT> </TD>

		<TD ALIGN="LEFT">Deletes the remote files on the remote machine. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>mdir </TT>remote-files </TD>

		<TD ALIGN="LEFT">Like <TT>dir</TT>, except multiple remote files may be specified. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>mget </TT>remote-files </TD>

		<TD ALIGN="LEFT">Expands the remote files on the remote machine and does a <TT>getfiles</TT> based

			on regular expressions. For example, <TT>mget f*.tar</TT> will get all the files

			starting with the letter f. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>open </TT>host<TT> [</TT>port<TT>]</TT> </TD>

		<TD ALIGN="LEFT">Establishes a connection to the specified host FTP server on the optional port number.

					</TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>put </TT>local-file </TD>

		<TD ALIGN="LEFT">Stores a local file on the remote machine. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>pwd</TT> </TD>

		<TD ALIGN="LEFT">Prints the name of the current working directory on the remote machine. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>quit</TT> </TD>

		<TD ALIGN="LEFT">Same as <TT>bye</TT>. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>remotehelp [</TT>command-name<TT>]</TT> </TD>

		<TD ALIGN="LEFT">Requests help from the remote FTP server. If a command name is specified, it is supplied

			to the server as well. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>reset</TT> </TD>

		<TD ALIGN="LEFT">Resets the communications connection. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>rmdir </TT>directory-name </TD>

		<TD ALIGN="LEFT">Deletes a directory on the remote machine. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>size </TT>file-name </TD>

		<TD ALIGN="LEFT">Returns the size of the file on the remote machine. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>status</TT> </TD>

		<TD ALIGN="LEFT">Shows the current status of <TT>ftp</TT>. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>verbose</TT> </TD>

		<TD ALIGN="LEFT">Displays all responses to the user. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>? [</TT>command<TT>]</TT> </TD>

		<TD ALIGN="LEFT">Same as <TT>help</TT>. </TD>

	</TR>

</TABLE>

Here are some of the options that may be specified at the command line: 

<TABLE BORDER="0">

	<TR ALIGN="LEFT" rowspan="1">

		<TD WIDTH="70" ALIGN="LEFT"><TT>-v</TT> </TD>

		<TD ALIGN="LEFT">The verbose option. Gives a report on the transfer statistics and forces <TT>ftp</TT>

			to show all responses from the remote server. <BR>

					</TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD WIDTH="70" ALIGN="LEFT">&#160;</TD>

		<TD ALIGN="LEFT">&#160;</TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD WIDTH="70" ALIGN="LEFT"><TT>-n</TT> </TD>

		<TD ALIGN="LEFT">Restrains <TT>ftp</TT> from attempting auto-login upon initial connection. In auto-login,

			<TT>ftp</TT> checks for </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD WIDTH="70" ALIGN="LEFT">			<P>

		</TD>

		<TD ALIGN="LEFT">the user's account on the remote machine. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD WIDTH="70" ALIGN="LEFT"><TT>-I</TT> </TD>

		<TD ALIGN="LEFT">Turns off interactive prompting during multiple file transfers. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD WIDTH="70" ALIGN="LEFT"><TT>-d<BR>

			</TT></TD>

		<TD ALIGN="LEFT">Enables debugging.<BR>

					</TD>

	</TR>

</TABLE>

Some <TT>ftp</TT> commands share the same name as Linux comman