As per Relevance of the word filename, we have this rfc below:
Network Working Group P.
Request for Comments: 1635 A.
FYI: 24
Category: Informational A.
NASA
May 1994
How to Use Anonymous
Status of this
This memo provides information for the Internet community. This
does not specify an Internet standard of any kind. Distribution
this memo is unlimited
This document provides information for the novice Internet user
using the File Transfer Protocol (FTP). It explains what FTP is
what anonymous FTP is, and what an anonymous FTP archive site is.
shows a sample anonymous FTP session. It also discusses common
files are packaged for efficient storage and transmission
This document is the result of work done in the Internet
FTP Archives (IAFA) working group of the IETF. Special thanks
due to Mark Baushke (Cisco), John Curran (BBN), Aydin Edguer (CWRU),
Rafal Maszkowski (Onsala Space Observatory), Marsha
(PREPnet), Bob Peterson (Texas Instruments), Nathan
(Victoria University of Wellington), and Stephen Tihor (NYU)
excellent comments and contributions
What is FTP
FTP refers to the File Transfer Protocol [1], one of the
within the TCP/IP protocol suite used on the Internet. The
Transfer Protocol makes it possible to transfer files from
computer (or host) on the Internet to another. There are many
implementations built on the specification of the FTP protocol.
user of an FTP program must log in to both hosts in order to
a file from one to the other
It is common for a user with files on more than one host to use
FTP program to transfer files from one host to another. In
case, the user has an account on both hosts involved, so he
passwords for both hosts
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RFC 1635 How To FTP May 1994
However, Internet users may also take advantage of a wealth
information available from archive sites by using a general
account called "anonymous FTP".
What is an Archive Site
An archive site is a host that acts as a repository of information
much like a conventional library. Information stored on
Internet hosts is made available for users to transfer to their
sites. Users run software to identify this information and
it to their own hosts. Such a transfer is done with a program
implements the File Transfer Protocol (FTP).
What is Anonymous FTP
Anonymous FTP is a means by which archive sites allow general
to their archives of information. These sites create a
account called "anonymous". User "anonymous" has limited
rights to the archive host, as well as some operating restrictions
In fact, the only operations allowed are logging in using FTP
listing the contents of a limited set of directories, and
files. Some sites limit the contents of a directory listing
anonymous user can see as well. Note that "anonymous" users are
usually allowed to transfer files TO the archive site, but can
retrieve files from such a site
Traditionally, this special anonymous user account accepts any
as a password, although it is common to use either the
"guest" or one's electronic mail (e-mail) address. Some
sites now explicitly ask for the user's e-mail address and will
allow login with the "guest" password. Providing an e-mail
is a courtesy that allows archive site operators to get some idea
who is using their services
What Information Do You Need to Know
To retrieve a specific file, a user needs to know what host it is on
and the pathname of the file. A pathname tells the directory (
possibly subdirectories) that house the file, and the name of
file. Often discussions of available files will not
say, "This file is available for anonymous FTP from X host with
pathname". However, if a file is publicly announced as available
referred to as something like pub/good-stuff on nisc.sri.com, it is
good assumption that you can try to transfer it
You may also need to know if your machine uses an ASCII, EBCDIC,
other character set to know how likely a transfer of
information will work, or whether such a transfer will require
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RFC 1635 How To FTP May 1994
keywords, such as is true for TENEX
In the general case, you may assume that an ASCII transfer
always do the right thing for plain text files. However, more
more information is being stored in various compressed formats (
are discussed later in this document), so knowing the
characteristics of your machine may be important
A Sample
To start an FTP session on a UNIX or VMS host, you type "ftp" and
host name or host IP address of the machine to which you want
connect. For example, if you wish to access the NASA
Applications and Information Center archive site, you would
execute one of the following commands at the UNIX prompt
ftp naic.nasa.
ftp 128.102.128.6
Observe that the first form uses the fully-qualified domain name
the second uses the Internet address for the same host
The following is an example of connecting to the naic.nasa.gov
to retrieve STD 9, RFC 959, "File Transfer Protocol (FTP)" [1].
Note several things about the session
1. Every response the FTP program at the archive site
is preceded by a number. These numbers are
Reply Codes and are defined in the FTP specification
RFC 959. The text that accompanies these reply
can vary in different FTP implementations, and usually does
Also note that some FTP client implementations (e.g.,
systems) may not echo the reply codes or text
transmitted from the remote host. They may generate
own status lines or just hide the non-fatal
from you. For the purposes of this document, the
popular UNIX interface to the FTP client will
presented
2. The password you type is never shown on your screen
3. It is possible to "browse" in archives, but most often
already know the pathname of the file they want. The
for RFC 959 on this host is files/rfc/rfc959.txt. In
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RFC 1635 How To FTP May 1994
example, we first connect to the 'files/rfc' directory (
files/rfc), then get the specific file we know we want. If
do not know the name of the file you want, a file called
or something similar (00README.1ST, AAREAD.ME, INDEX, etc.)
probably the one to retrieve first
atlas.arc.nasa.gov% ftp naic.nasa.
Connected to naic.nasa.gov
220 naic.nasa.gov FTP server (Wed May 4 12:15:15 PDT 1994) ready
Name (naic.nasa.gov:amarine):
331 Guest login ok, send your complete e-mail address as password
Password
230-----------------------------------------------------------------
230-Welcome to the NASA Network Applications and Info Center
230-
230- Access to NAIC's online services is also available through
230-
230- Gopher - naic.nasa.gov (port 70)
230- World-Wide-Web - http://naic.nasa.gov/naic/naic-home.
230-
230- If you experience any problems please send email
230-
230- naic@nasa.
230-
230- or call +1 (800) 858-9947
230-----------------------------------------------------------------
230-
230-Please read the file
230- it was last modified on Fri Dec 10 13:06:33 1993 - 165 days
230 Guest login ok, access restrictions apply
ftp> cd files/
250-Please read the file README.
250- it was last modified on Fri Jul 30 16:47:29 1993 - 298 days
250 CWD command successful
ftp> get rfc959.
200 PORT command successful
150 Opening ASCII mode data connection for rfc959.txt (147316 bytes).
226 Transfer complete
local: rfc959.txt remote: rfc959.
151249 bytes received in 0.9 seconds (1.6e+02 Kbytes/s
ftp>
221 Goodbye
atlas.arc.nasa.gov
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RFC 1635 How To FTP May 1994
The above example is of the FTP program available on UNIX systems
Other operating systems also make FTP programs available. The
commands you type may vary somewhat with other programs. However,
general, you will do the following with every FTP program
- Log in to your local host, and invoke the FTP program
- Open a connection to the host (using either the host
or its IP address
- Once connected to the remote host, log in with
"anonymous".
- Provide either the password "guest" or whatever the password
site requests
- Issue whatever FTP commands you require, such as those
change directories or to retrieve a file
- When finished, exit the FTP program, which will close
connection to the archive host
Friendly
These days, many sites are using a form of FTP that allows them
display several lines of explanatory text that help direct
through their archive. The listing of alternative services
naic.nasa.gov is an example. If these effusive servers confuse
client you are using, try typing a hyphen ( - ) before your
when you log in. That should disable the verbose mode of the server
Other FTP
We have demonstrated some of the commands available with
programs. Many others are possible. For example, once you
logged in to a remote host
- You may ask the FTP program to display a list of
commands, typically by invoking the FTP program
arguments and typing "help".
- You may view the contents of the directory to which you
connected. Type "dir" or "ls" to do so
- You may rename a file by using the "get" command'
optional local file name, which follows the remote
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RFC 1635 How To FTP May 1994
name on the command line. You probably should rename
file when the remote file name exceeds your local
system's naming constraints, e.g., if the remote
name is too long. An example of using the "get"
to rename a file when transferring it might be "
really-long-named-file.txt short.txt".
- You may set BINARY mode to transfer executable programs or
of data. Type "binary" to do so.
FTP programs assume files use only 7 bits per byte, the norm
standard ASCII-encoded files. The BINARY command allows you
transfer files that use the full 8 bits per byte without error
but this may have implications on how the file is
to your local system
If you are not sure what format a file is in, you may need
transfer it a second time in the other mode (BINARY or ASCII
if your first guess is wrong. The extension at the end of
file name may give you a clue. File name extensions
described below
Because some machines store text files differently than others
you may have to try your luck if you're not sure what
a file is in. A good guess is to try ASCII mode first,
you have grounds to suspect the file is a text file. Otherwise
try BINARY mode. Try TENEX mode as a last resort
- You may transfer multiple files at the same time. To set
mode, type "mget". You then supply a file name pattern
the remote system understands and it tries to transfer
file in turn. If your local FTP user agent cannot
the remote file names into legal local file names, or if
are some files that must be transferred in ASCII mode and
that must be transferred in BINARY mode, you may not be able
take advantage of this facility
Full details on the commands and options available are in the
documentation that comes with your system. You can also type "help
at the FTP command prompt for a list of command options
A copy of the UNIX version of the FTP documentation is available
the online manual. If your UNIX site has the manuals installed,
the following at the UNIX prompt
% man
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RFC 1635 How To FTP May 1994
The Packaging and Naming of
Several widely used conventions allow for efficient storage
transmission of information stored at archive sites
Information stored on archive sites is often "transformed" in
common ways. "Compressing" (reducing the size of) the
information makes more space available on the archive, and
the amount of data actually transferred across the network
"Bundling" several files into one larger file maintains the
directory structure of the components, and allows users to
only one larger object rather than several (sometimes hundreds)
smaller files
In addition, binary data is often converted into an ASCII format
transmission, a process referred to in this document
"transformation". Traditionally, Internet RFC 822-based
mail and USENET protocols did not allow the transmission of "binary
(8-bit) data; therefore, files in binary format had to be
into printable 7-bit ASCII before being transmission
On many systems, various file naming conventions are used to help
remote user to determine the format of the stored information
first having to retrieve the files. Below we list the more
compression, bundling, and transformation conventions used on
Internet. This list is not intended to be exhaustive. In all
public domain or freely-available implementations of the
associated with these mechanisms are available on the network
1) compress/
Filenames terminating in ".Z" normally signify files that have
compressed by the standard UNIX Lempel-Ziv "compress" utility
There is an equivalent program called "uncompress" to reverse
process and return the file to its original state. No
mechanism is provided, and the resulting files are always in
format, regardless of the original format of the input data
2) atob/
Performs a transformation of ASCII to binary (atob) and the
(btoa) in a standard format. Files so transformed often
filenames terminated with ".atob". No bundling or
mechanisms are used
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RFC 1635 How To FTP May 1994
3) atox/
A data transformation standard used to convert
files to transferable ASCII format. Sometimes used
preference to other similar mechanisms because it is
space efficient; however, it is not a
mechanism per se. It is just more efficient in
transformation from one format to the other. Filenames
files in this format often have the ".atox" extension
4) uuencode/
Transforms binary to ASCII ("uuencode") and the
("uudecode") transformation in a standard manner
Originally used in the UUCP ("Unix to Unix CoPy")
mail/USENET system. No bundling or compression
are used. Naming conventions often add a .uu at the
of the file name
5) tar/
Originally a UNIX based utility for bundling (
unbundling) several files and directories into (and from
a single file (the acronym stands for "Tape ARchive").
Standard format provides no compression mechanism.
resulting bundled file is always in binary
regardless of whether the constituent files are binary
not. Naming conventions usually hold that the filename
a "tarfile" contain the sequence ".tar" or "-tar".
6) zip/
Often used in IBM PC environments, these complementary
provide both bundling and compression mechanisms. The
files are always in binary format. Files resulting from the "zip
program are by convention terminated with the ".zip"
extension
7) arc/
Often used in IBM PC environments, these complementary
provide both bundling and compression mechanisms. The
files are always in binary format. Files stored in this
often have a ".arc" filename extension
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RFC 1635 How To FTP May 1994
8)
Used in the Apple MacIntosh environment, the
process provides bundling as well as binary to ASCII
transformations. Files in this format by convention
a filename extension of ".hqx".
9)
Bourse shell archives package text or binary files into
single longer file which, when executed, will create
component files. Because this format is vulnerable
misuse, most users use a special tool called unshar
decode these archives. By convention, files in
format have a filename extension of ".shar".
10) VMS_
DCL archives package text or binary files into a
longer file which, when executed, will created
component files. Because this format is vulnerable
misuse, care must be take to examine such an
before executing it. By convention, files in this
have a filename extension of ".shar".
11) Multipart shar/vms_share
Sometimes these shell archive files are broken
multiple small parts to simplify their transfer over
forms of fileservers that share the same archive tree.
such cases, the parts of the files are usually
with a part number (e.g., xyz.01 xyz.02 xyz.03 ... or
.01-of-05). Collect all the parts, concatenate them
your local system, and then apply the procedure
above for a simple shar or vms_share file to
concatenated file you just made
12)
The zoo program implements compression/decompression
bundling/unbundling in a single program.
supporting the zoo format exist on a wide variety
systems, including Unix, MS-DOS, Macintosh, OS/2,
ST, and VAX VMS. Files created by the "zoo" programs
convention end with the ".zoo" filename extension. Zoo
a popular distribution format due to the availability
free implementations (both source and executable code)
a wide variety of operating systems
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RFC 1635 How To FTP May 1994
13) gzip/
The Free Software Foundation GNU project adopted a
of the zip compression mechanism as a substitute for
compress/uncompress commands. The resulting files
always in binary format. Files resulting from the "gzip
program are by convention terminated with the ".z"
".gz" filename extensions. The gunzip program
recognizes ".tgz" and ".taz" as shorthands for ".tar.z"
".tar.Z". Also, gunzip can recognize and decompress
created by the gzip, zip, compress, or pack commands
The GNU project recently began distributing and using
gzip/gunzip utilities. Even more recently they
the default suffix from .z to .gz, in an attempt to (1)
reduce confusion with .Z, and (2) eliminate a problem
case-insensitive file systems such as MS-DOS. The
software is freely redistributable and has been ported
most UNIX systems, as well as Amiga, Atari, MSDOS, OS2,
and VMS systems
In some cases, a series of the above processes are performed
produce the final file as stored on the archive. In cases
multiple transformation processes have been used, tradition
that the original (base) filename be changed to reflect
processes, and that the associated filename extensions be added
the order in which the processes were performed. For example,
common procedure is first to bundle the original files
directories using the "tar" process, then to "compress" the
file. Starting with a base file name of "foobar", the file name
the archive would become "foobar.tar.Z". As this is a binary file
it would require a further transformation into printable ASCII by
program such as "uuencode" in order to be transmitted
traditional email or USENET facilities, so it might finally be
"foobar.tar.Z.uu."
Some operating systems can not handle multiple periods; in such
they are often replaced by hyphen ( - ), underscore ( _ ), or
detailed instructions in the "read me" files in the directories
Compress and
Here is an example of the use of the "compress/uncompress"
"tar/untar" programs
Suppose "patch" is a useful public domain program for
program patches and updates. You find this file at an archive
as "patch.tar.Z". Now you know that the ".Z" indicates that the
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RFC 1635 How To FTP May 1994
was compressed with the UNIX "compress" command, and the ".tar
indicates that it was tar'ed using the UNIX "tar" tape
command
First retrieve the file onto your machine using anonymous FTP.
unpack this program, you would first uncompress it by typing
uncompress patch.tar.
This will uncompress the file, and in the process, rename it
"patch.tar". You can then execute the "tar" command to extract
individual files
In the example of patch.tar, you could invoke the command as
%tar xvf patch.
The files would be extracted (that's the 'x' argument to tar)
the file patch.tar (that's the 'f' argument). Because we use the 'v
(for verbose) argument, the name of each file is printed as it
extracted. When tar is complete you should have all the files
make up the "patch" program in your working directory
Not every site that supports FTP permits anonymous tranfers. It
wrong to try to get files from systems that have not advertised
availability of such a service
Remember that Internet site administrators for archive sites
made their systems available out of a sense of community. Rarely
they fully compensated for the time and effort it takes to
such a site. There are some things users can do to make their
somewhat easier, such as checking with local support personnel
if problems occur before asking the archive administrator for help
Most archive machines perform other functions as well.
respect the needs of their primary users and restrict your FTP
to non-prime hours (generally between 1900 and 0600 hours local
for that site) whenever possible. It is especially important
remember this for sites located on another continent or across
significant body of water because most such links are relatively
and heavily loaded
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RFC 1635 How To FTP May 1994
In addition, some sites offering anonymous FTP limit the number
concurrent anonymous FTP logins. If your attempt to log onto such
site results in an error message to the effect that too
anonymous FTP users are online, you should wait a while
attempting another connection rather than retrying immediately
To reduce redundant storage, you should find out how to make
the files you fetch using FTP available to your entire organization
If you retrieve and test a program that turns out to be useful,
should probably ask your administrator to consider making the
generally available, which will reduce the redundant effort and
space resulting from multiple individuals installing the same
in their personal directories
If you find an interesting file or program on an archive site,
others about it. You should not copy the file or program to your
archive unless you are willing to keep your copy current
[1] Postel, J., and J. Reynolds, "File Transfer Protocol (FTP)",
9, RFC 959, USC/Information Sciences Institute, October 1985.
Security
Security issues are not discussed in this memo
IAFA Working Group [Page 12]
RFC 1635 How To FTP May 1994
Authors'
Peter
Bunyip Information
266 Blvd.
Dorval, Quebec, H9S 2L
Phone: (514) 398-3709
EMail: peterd@bunyip.
Alan
Bunyip Information
266 Blvd.
Dorval, Quebec, H9S 2L
Phone: (514) 398-3709
EMail: bajan@bunyip.
April N.
NASA
M/S 204-14
Ames Research
Moffett Field, CA 94035-1000
Phone: (415) 604-0762
EMail: amarine@atlas.arc.nasa.
IAFA Working Group [Page 13]
if you see any problems within the linking, don't worry be happy,
this is version 0.1 of the Relevance System and you gotta expect some crappy subroutines sometimes,
just be content we did not write this in Java, which would have made this "bigger and better" HAHAHHA.
RFC documents can be found at I.E.T.F.
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