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NAME
ncftp - Browser program for the File Transfer Protocol
SYNOPSIS
ncftp [host]
ncftp [ftp://host.name/directory/]
DESCRIPTION
The purpose of ncftp is to provide a powerful and flexible
interface to the Internet standard File Transfer Protocol.
It is intended to replace the stock ftp program that comes
with the system.
Although the program appears to be rather spartan, you'll
find that ncftp has a wealth of valuable performance and
usage features. The program was designed with an emphasis
on usability, and it does as much as it can for you automat-
ically so you can do what you expect to do with a file
transfer program, which is transfer files between two inter-
connected systems.
Some of the cooler features include progress meters,
filename completion, command-line editing, background pro-
cessing, auto-resume downloads, bookmarking, cached direc-
tory listings, host redialing, working with firewalls and
proxies, downloading entire directory trees, etc., etc.
The ncftp distribution comes with the useful utility pro-
grams ncftpget(1) and ncftpput(1) which were designed to do
command-line FTP. In particular, they are very handy for
shell scripts. This version of ncftp no longer does
command-line FTP, since the main ncftp program is more of a
browser-type program.
INTRODUCTION TO THE COMMAND SHELL
Upon running the program you are presented a command prompt
where you type commands to the program's shell. Usually you
will want to open a remote filesystem to transfer files to
and from your local machine's filesystem. To do that, you
need to know the symbolic name of the remote system, or its
Internet Protocol (IP) address. For example, a symbolic
name might be ``typhoon.unl.edu,'' and its IP address could
be ``129.93.33.24.'' To open a connection to that system,
you use the program's open command:
open typhoon.unl.edu
open 129.93.33.24
Both of these try to open the machine called typhoon at the
University of Nebraska. Using the symbolic name is the pre-
ferred way, because IP addresses may change without notice,
while the symbolic names usually stay the same.
When you open a remote filesystem, you need to have permis-
sion. The FTP Protocol's authentication system is very
similar to that of logging in to your account. You have to
give an account name, and its password for access to that
account's files. However, most remote systems that have
anything you might be interested in don't require an account
name for use. You can often get anonymous access to a
remote filesystem and exchange files that have been made
publicly accessible. The program attempts to get anonymous
permission to a remote system by default. What actually
happens is that the program tries to use ``anonymous'' as
the account name, and when prompted for a password, uses
your E-mail address as a courtesy to the remote system's
maintainer. You can have the program try to use a specific
account also. That will be explained later.
After the open command completes successfully, you are con-
nected to the remote system and logged in. You should now
see the command prompt change to reflect the name of the
current remote directory. To see what's in the current
remote directory, you can use the program's ls and dir com-
mands. The former is terse, preferring more remote files in
less screen space, and the latter is more verbose, giving
detailed information about each item in the directory.
You can use the program's cd command to move to other direc-
tories on the remote system. The cd command behaves very
much like the command of the same name in the Bourne and
Korn shell.
The purpose of the program is to exchange data with other
systems. You can use the program's get command to copy a
file from the remote system to your local system:
get README.txt
The program will display the progress of the transfer on the
screen, so you can tell how much needs to be done before the
transfer finishes. When the transfer does finish, then you
can enter more commands to the program's command shell.
You can use the program's put command to copy a file from
your system to the remote system:
put something.tar
When you are finished using the remote system, you can open
another one or use the quit
Before quitting, you may want to save the current FTP
session's settings for later. You can use the bookmark com-
mand to save an entry into your $HOME/.ncftp/bookmarks file.
When you use the bookmark command, you also specify a book-
mark name, so the next time instead of opening the full
hostname you can use the name of the bookmark. A bookmark
acts just like one for your web browser, so it saves the
remote directory you were in, the account name you used,
etc., and other information it learned so that the next time
you use the bookmark it should require as little effort from
you as possible.
COMMAND REFERENCE
help The first command to know is help. If you just type
help
from the command shell, the program prints the names of
all of the supported commands. From there, you can get
specific help for a command by typing the command
after, for example:
help open
prints information about the open command.
ascii
This command sets the transfer type to ASCII text.
This is useful for text-only transfers because the con-
cept of text files differs between operating systems.
For example on UNIX, a text file denotes line breaks
with the linefeed character, while on MS-DOS a line
break is denoted by both a carriage return character
and a line feed character. Therefore, for data
transfers that you consider the data as text you can
use ascii to ensure that both the remote system and
local system translate accordingly. The default
transfer type that ncftp uses is not ASCII, but
straight binary.
bgget and bgput
These commands correspond to the get and put commands
explained below, except that they do the job in the
background. Normally when you do a get then the pro-
gram does the download immediately, and does not return
control to you until the download completes. The back-
ground transfers are nice because you can continue
browsing the remote filesystem and even open other sys-
tems. In fact, they are done by a daemon process, so
even if you log off your UNIX host the daemon should
still do your transfers. The daemon will also automat-
ically continue to retry the transfers until they fin-
ish. To tell when background jobs have finished, you
have to examine the $HOME/.ncftp/batchlog file, or run
the jobs command from within NcFTP.
Both the bgget and bgput commands allow you to schedule
when to do the transfers. They take a ``-@'' parame-
ter, whose argument is a date of the form
YYYYMMDDhhmmss (four digit year, month, day, hour,
minute, second). For example, to schedule a download
at 3 AM on November 6, you could try:
bgget -@ 19971106030000 /pub/idstuff/quake/q2_100.zip
bgstart
This command tells ncftp to immediately start the back-
ground transfers you've requested, which simply runs a
copy of the ncftpbatch program which is responsible for
the background jobs. Normally the program will start
the background job as soon as you close the current
site, open a new site, or quit the program. The reason
for this is because since so many users still use slow
dialup links that starting the transfers would slow
things to a crawl, making it difficult to browse the
remote system. An added bonus of starting the back-
ground job when you close the site is that ncftp can
pass off that open connection to the ncftpbatch pro-
gram. That is nice when the site is always busy, so
that the background job doesn't have to wait and get
re-logged on to do its job.
binary
Sets the transfer type to raw binary, so that no trans-
lation is done on the data transferred. This is the
default anyway, since most files are in binary.
bookmark
Saves the current session settings for later use. This
is useful to save the remote system and remote working
directory so you can quickly resume where you left off
some other time. The bookmark data is stored in your
$HOME/.ncftp/bookmarks file.
bookmarks
Lists the contents of your $HOME/.ncftp/bookmarks file
in a human-readable format. You can use this command
to recall the bookmark name of a previously saved book-
mark, so that you can use the open command with it.
cat Acts like the ``/bin/cat'' UNIX command, only for
remote files. This downloads the file you specify and
dumps it directly to the screen. You will probably
find the page command more useful, since that lets you
view the file one screen at a time instead of printing
the entire file at once.
cd Changes the working directory on the remote host. Use
this command to move to different areas on the remote
server. If you just opened a new site, you might be in
the root directory. Perhaps there was a directory
called ``/pub/news/comp.sources.d'' that someone told
you about. From the root directory, you could:
cd pub
cd news
cd comp.sources.d
or, more concisely,
cd /pub/news/comp.sources.d
Then, commands such as get, put, and ls could be used
to refer to items in that directory.
Some shells in the UNIX environment have a feature I
like, which is switching to the previous directory.
Like those shells, you can do:
cd -
to change to the last directory you were in.
chmod
Acts like the ``/bin/chmod'' UNIX command, only for
remote files. However, this is not a standard command,
so remote FTP servers may not support it.
close
Disconnects you from the remote server. The program
does this for you automatically when needed, so you can
simply open other sites or quit the program without
worrying about closing the connection by hand.
debug
This command is mostly for internal testing. You could
type
debug 1
to turn debugging mode on. Then you could see all mes-
sages between the program and the remote server, and
things that are only printed in debugging mode. How-
ever, this information is also available in the
$HOME/.ncftp/trace file, which is created each time you
run ncftp. If you need to report a bug, send a trace
file if you can.
dir Prints a detailed directory listing. It tries to
behave like UNIX's ``/bin/ls -l'' command. If the
remote server seems to be a UNIX host, you can also use
the same flags you would with ls, for instance
dir -rt
would try to act like
/bin/ls -lrt
would on UNIX.
get Copies files from the current working directory on the
remote host to your machine's current working direc-
tory. To place a copy of ``README'' and ``README.too''
in your local directory, you could try:
get README README.too
You could also accomplish that by using a wildcard
expression, such as:
get README*
This command is similar to the behavior of other FTP
programs' mget command. To retrieve a remote file but
give it a different name on your host, you can use the
``-z'' flag. This example shows how to download a file
called ReadMe.txt but name it locally as README:
get -z ReadMe.txt README
The program tries to ``resume'' downloads by default.
This means that if the remote FTP server lost the con-
nection and was only able to send 490 kilobytes of a
500 kilobyte file, you could reconnect to the FTP
server and do another get on the same file name and it
would get the last 10 kilobytes, instead of retrieving
the entire file again. There are some occasions where
you may not want that behavior. To turn it off you can
use the ``-Z'' flag.
There are also times where you want to append to an
existing file. You can do this by using the ``-A''
flag, for example
get -A log.11
would append to a file named ``log.11'' if it existed
locally.
Another thing you can do is delete a remote file after
you download it. This can be useful when a remote host
expects a file to be removed when it has been
retrieved. Use the double-D flag, such as ``get -DD''
to do this.
The get command lets you retrieve entire directory
trees, too. Although it may not work with some remote
systems, you can try ``get -R'' with a directory to
download the directory and its contents.
jobs Views the list of currently executing NcFTP background
tasks. This actually just runs ncftpbatch -l for you.
lcd The lcd command is the first of a few ``l'' commands
that work with the local host. This changes the
current working directory on the local host. If you
want to download files into a different local direc-
tory, you could use lcd to change to that directory and
then do your downloads.
lchmod
Runs ``/bin/chmod'' on the local host.
lls Another local command that comes in handy is the lls
command, which runs ``/bin/ls'' on the local host and
displays the results in the program's window. You can
use the same flags with lls as you would in your com-
mand shell, so you can do things like:
lcd ~/doc
lls -lrt p*.txt
lmkdir
Runs ``/bin/mkdir'' on the local host.
lookup
The program also has a built-in interface to the name
service via the lookup command. This means you can
lookup entries for remote hosts, like:
lookup cse.unl.edu ftp.cs.unl.edu sphygmomanometer.unl.edu
prints:
cse.unl.edu 129.93.33.1
typhoon.unl.edu 129.93.33.24
sphygmomanometer.unl.edu 129.93.33.126
There is also a more detailed option, enabled with
``-v,'' i.e.:
lookup -v cse.unl.edu ftp.cs.unl.edu
prints:
cse.unl.edu:
Name: cse.unl.edu
Address: 129.93.33.1
ftp.cs.unl.edu:
Name: typhoon.unl.edu
Alias: ftp.cs.unl.edu
Address: 129.93.33.24
You can also give IP addresses, so this would work too:
lookup 129.93.33.24
prints:
typhoon.unl.edu 129.93.33.24
lpage
Views a local file one page at a time, with your pre-
ferred $PAGER program.
lpwd Prints the current local directory. Use this command
when you forget where you are on your local machine.
lrename
Runs ``/bin/mv'' on the local host.
lrm Runs ``/bin/rm'' on the local host.
lrmdir
Runs ``/bin/rmdir'' on the local host.
ls Prints a directory listing from the remote system. It
tries to behave like UNIX's ``/bin/ls -CF'' command.
If the remote server seems to be a UNIX host, you can
also use the same flags you would with ls, for instance
ls -rt
would try to act like
/bin/ls -CFrt
would on UNIX.
ncftp has a powerful built-in system for dealing with
directory listings. It tries to cache each one, so if
you list the same directory, odds are it will display
instantly. Behind the scenes, ncftp always tries a
long listing, and then reformats it as it needs to. So
even if your first listing of a directory was a regular
``ls'' which displayed the files in columns, your next
listing could be ``ls -lrt'' and ncftp would still use
the cached directory listing to quickly display the
information for you!
mkdir
Creates a new directory on the remote host. For many
public archives, you won't have the proper access per-
missions to do that.
open Establishes an FTP control connection to a remote host.
By default, ncftp logs in anonymously to the remote
host. You may want to use a specific user account when
you log in, so you can use the ``-u'' flag to specify
which user. This example shows how to open the host
``bowser.nintendo.co.jp'' using the username ``mario:''
open -u mario bowser.nintendo.co.jp
page Browses a remote file one page at a time, using your
$PAGER program. This is useful for reading README's on
the remote host without downloading them first.
pdir and pls
These commands are equivalent to dir and ls
respectively, only they feed their output to your
pager. These commands are useful if the directory
listing scrolls off your screen.
put Copies files from the local host to the remote
machine's current working directory. To place a copy
of ``xx.zip'' and ``yy.zip'' in the remote directory,
you could try:
put xx.zip yy.zip
You could also accomplish that by using a wildcard
expression, such as:
put *.zip
This command is similar to the behavior of other FTP
programs' mput command. To send a remote file but give
it a different name on your host, you can use the
``-z'' flag. This example shows how to upload a file
called ``ncftpd-2.0.6.tar.gz'' but name it remotely as
``NFTPD206.TGZ:''
put -z ncftpd-2.0.6.tar.gz NFTPD206.TGZ
The program does not try to ``resume'' uploads by
default. If you do want to resume an upload, use the
``-z'' flag.
There are also times where you want to append to an
existing remote file. You can do this by using the
``-A'' flag, for example
put -A log11.txt
would append to a file named ``log11.txt'' if it
existed on the remote server.
Another thing you can do is delete a local file after
you upload it. Use the double-D flag, such as
``put -DD'' to do this.
The put command lets you send entire directory trees,
too. It should work on all remote systems, so you can
try ``put -R'' with a directory to upload the directory
and its contents.
pwd Prints the current remote working directory. A portion
of the pathname is also displayed in the shell's
prompt.
quit Of course, when you finish using the program, type quit
to end the program (You could also use bye, exit, or
^D).
quote
This can be used to send a direct FTP Protocol command
to the remote server. Generally this isn't too useful
to the average user.
rename
If you need to change the name of a remote file, you
can use the rename command, like:
rename SPHYGMTR.TAR sphygmomanometer-2.3.1.tar
rhelp
Sends a help request to the remote server. The list of
FTP Protocol commands is often printed, and sometimes
some other information that is actually useful, like
how to reach the site administrator.
Depending on the remote server, you may be able to give
a parameter to the server also, like:
rhelp NLST
One server responded:
Syntax: NLST [ <sp> path-name ]
rm If you need to delete a remote file you can try the rm
command. Much of the time this won't work because you
won't have the proper access permissions. This command
doesn't accept any flags, so you can't nuke a whole
tree by using ``-rf'' flags like you can on UNIX.
rmdir
Similarly, the rmdir command removes a directory.
Depending on the remote server, you may be able to
remove a non-empty directory, so be careful.
set This lets you configure some program variables, which
are saved between runs in the $HOME/.ncftp/prefs file.
The basic syntax is:
set <option> <value>
For example, to change the value you use for the
anonymous password, you might do:
set anon-password [email protected]
See the next section for a list of things you change.
show This lets you display program variables. You can do
``show all'' to display all of them, or give a variable
name to just display that one, such as:
show anon-password
site One obscure command you may have to use someday is
site. The FTP Protocol allows for ``site specific''
commands. These ``site'' commands vary of course, such
as:
site chmod 644 README
Actually, ncftp's chmod command really does the above.
Try doing one of these to see what the remote server
supports, if any:
rhelp SITE
site help
type You may need to change transfer types during the course
of a session with a server. You can use the type com-
mand to do this. Try one of these:
type ascii
type binary
type image
The ascii command is equivalent to ``type a'', and the
binary command is equivalent to ``type i'' and
``type b''.
umask
Sets the process' umask on the remote server, if it has
any concept of a umask, i.e.:
umask 077
However, this is not a standard command, so remote FTP
servers may not support it.
version
This command dumps some information about the particu-
lar edition of the program you are using, and how it
was installed on your system.
VARIABLE REFERENCE
anon-password
Specifies what to use for the password when logging in
anonymously. Internet convention has been to use your
E-mail address as a courtesy to the site administrator.
If you change this, be aware that some sites require
(i.e. they check for) valid E-mail addresses.
auto-resume
NcFTP 3 now prompts the user by default when you try to
download a file that already exists locally, or upload
a file that already exists remotely. Older versions of
the program automatically guessed whether to overwrite
the existing file or attempt to resume where it left
off, but sometimes the program would guess wrong. If
you would prefer that the program always guess which
action to take, set this variable to yes, otherwise,
leave it set to no and the program will prompt you for
which action to take.
autosave-bookmark-changes
With the advent of version 3 of NcFTP, the program
treats bookmarks more like they would with your web
browser, which means that once you bookmark the site,
the remote directory is static. If you set this vari-
able to yes, then the program will automatically update
the bookmark's starting remote directory with the
directory you were in when you closed the site. This
behavior would be more like that of NcFTP version 2.
confirm-close
By default the program will ask you when a site you
haven't bookmarked is about to be closed. To turn this
prompt off, you can set this variable to no.
connect-timeout
Previous versions of the program used a single timeout
value for everything. You can now have different
values for different operations. However, you probably
do not need to change these from the defaults unless
you have special requirements.
The connect-timeout variable controls how long to wait,
in seconds, for a connection establishment to complete
before considering it hopeless. You can choose to not
use a timeout at all by setting this to -1.
control-timeout
This is the timer used when ncftp sends an FTP command
over the control connection to the remote server. If
the server hasn't replied in that many seconds, it con-
siders the session lost.
logsize
This is controls how large the transfer log
($HOME/.ncftp/log) can grow to, in kilobytes. The
default is 200, for 200kB; if you don't want a log, set
this to 0.
pager
This is the external program to use to view a text
file, and is more by default.
passive
This controls ncftp's behavior for data connections,
and can be set to one of on, off, or the default,
optional. When passive mode is on, ncftp uses the FTP
command primitive PASV to have the client establish
data connections to the server. The default FTP proto-
col behavior is to use the FTP command primitive PORT
which has the server establish data connections to the
client. The default setting for this variable,
optional, allows ncftp to choose whichever method it
deems necessary.
progress-meter
You can change how the program reports file transfer
status. Select from meter 2, 1, or 0.
redial-delay
When a host is busy or unavailable, the program waits
this number of seconds before trying again. The smal-
lest you can set this is to 10 seconds -- so if you
were planning on being inconsiderate, think again.
save-passwords
If you set this variable to yes, the program will save
passwords along with the bookmarks you save. While
this makes non-anonymous logins more convenient, this
can be very dangerous since your account information is
now sitting in the $HOME/.ncftp/bookmarks file. The
passwords aren't in clear text, but it is still trivial
to decode them if someone wants to make a modest
effort.
so-bufsize
If your operating system supports TCP Large Windows,
you can try setting this variable to the number of
bytes to set the TCP/IP socket buffer to. This option
won't be of much use unless the remote server also sup-
ports large window sizes and is pre-configured with
them enabled.
xfer-timeout
This timer controls how long to wait for data blocks to
complete. Don't set this too low or else your
transfers will timeout without completing.
FIREWALL AND PROXY CONFIGURATION
You may find that your network administrator has placed a
firewall between your machine and the Internet, and that you
cannot reach external hosts.
The answer may be as simple as setting ncftp to use passive
mode only, which you can do from a ncftp command prompt like
this:
set passive yes
The reason for this is because many firewalls do not allow
incoming connections to the site, but do allow users to
establish outgoing connections. A passive data connection
is established by the client to the server, whereas the
default is for the server to establish the connection to the
client, which firewalls may object to. Of course, you now
may have problems with sites whose primitive FTP servers do
not support passive mode.
Otherwise, if you know you need to have ncftp communicate
directly with a firewall or proxy, you can try editing the
separate $HOME/.ncftp/firewall configuration file. This
file is created automatically the first time you run the
program, and contains all the information you need to get
the program to work in this setup.
The basics of this process are configuring a firewall
(proxy) host to go through, a user account and password for
authentication on the firewall, and which type of firewall
method to use. You can also setup an exclusion list, so
that ncftp does not use the firewall for hosts on the local
network.
FILES
$HOME/.ncftp/batchlog
Information for background data transfer processes.
$HOME/.ncftp/bookmarks
Saves bookmark and host information.
$HOME/.ncftp/firewall
Firewall access configuration file.
$HOME/.ncftp/prefs
Program preferences.
$HOME/.ncftp/spool/
Directory where background jobs are stored in the form
of spool configuration files.
$HOME/.ncftp/trace
Debugging output for entire program run.
$HOME/.ncftp/v3init
Used to tell if this version of the program has run
before.
ENVIRONMENT
PATH User's search path, used to find the ncftpbatch pro-
gram, pager, and some other system utilities.
PAGER
Program to use to view text files one page at a time.
TERM If the program was compiled with support for GNU Read-
line it will need to know how to manipulate the termi-
nal correctly for line-editing, etc. The pager program
will also take advantage of this setting.
HOME By default, the program writes its configuration data
in a .ncftp subdirectory of the HOME directory.
NCFTPDIR
If set, the program will use this directory instead of
$HOME/.ncftp. This variable is optional except for
those users whose home directory is the root directory.
COLUMNS
Both the built-in ls command and the external ls com-
mand need this to determine how many screen columns the
terminal has.
BUGS
There are no such sites named bowser.nintendo.co.jp or
sphygmomanometer.unl.edu.
Auto-resume should check the file timestamps instead of
relying upon just the file sizes, but it is difficult to do
this reliably within FTP.
Directory caching and recursive downloads depend on
UNIX-like behavior of the remote host.
AUTHOR
Mike Gleason, NcFTP Software ([email protected]).
SEE ALSO
ncftpput(1), ncftpget(1), ncftpbatch(1), ftp(1), rcp(1),
tftp(1).
LibNcFTP (http://www.ncftp.com/libncftp).
NcFTPd (http://www.ncftp.com/ncftpd).
THANKS
Thanks to everyone who uses the program. Your support is
what drives me to improve the program!
I thank Dale Botkin and Tim Russell at my former ISP, Probe
Technology.
Ideas and some code contributed by my partner, Phil Dietz.
Thanks to Brad Mittelstedt and Chris Tjon, for driving and
refining the development of the backbone of this project,
LibNcFTP.
I'd like to thank my former system administrators, most not-
ably Charles Daniel, for making testing on a variety of
platforms possible, letting me have some extra disk space,
and for maintaining the UNL FTP site.
For testing versions 1 and 2 above and beyond the call of
duty, I am especially grateful to: Phil Dietz, Kok Hon Yin,
and Andrey A. Chernov ([email protected]).
Thanks to Tim MacKenzie ([email protected]) for the ori-
ginal filename completion code for version 2.3.0 and 2.4.2.
Thanks to DaviD W. Sanderson ([email protected]), for helping me
out with the man page.
Thanks to those of you at UNL who appreciate my work.
Thanks to Red Hat Software for honoring my licensing agree-
ment, but more importantly, thanks for providing a solid and
affordable development platform.
APOLOGIES
To the users, for not being able to respond personally to
most of your inquiries.
To Phil, for things not being the way they should be.
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