man ncftp Command

Man page for apt-get ncftp Command

Man Page for ncftp in Linux

Ubuntu Man Command : man ncftp

Man Ncftp  Command

This tutorial shows the man page for man ncftp in linux.

Open terminal with 'su' access and type the command as shown below:
man ncftp

Result of the Command Execution shown below:

ncftp(1)                                                                                                                                                    ncftp(1)



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 automatically so you can do what you expect to do with a file transfer program, which is
transfer files between two interconnected systems.

Some of the cooler features include progress meters, filename completion, command line editing, background processing, auto resume downloads, bookmarking,
cached directory listings, host redialing, working with firewalls and proxies, downloading entire directory trees, etc., etc.

The ncftp distribution comes with the useful utility programs 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.

OPTIONS
The program allows you to specify a host or directory URL on the command line. This is a synonym for running ncftp and then using the open command. A few
command line flags are allowed with this mode:

u XX Use username XX instead of anonymous.

p XX Use password XX with the username.

j XX Use account XX in supplement to the username and password (deprecated).

P XX Use port number XX instead of the default FTP service port (21).

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 filesys Äê
tem 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 Pro Äê
tocol (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 preferred 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 permission. 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 connected 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 commands. 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 directories 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 trans Äê
fer 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 command to save an entry into your
$HOME/.ncftp/bookmarks file. When you use the bookmark command, you also specify a bookmark 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 concept 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 program does the download immediately, and does not return control to you until the download completes. The background transfers are nice because
you can continue browsing the remote filesystem and even open other systems. 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 automatically continue to retry the transfers until they finish. To tell
when background jobs have finished, you have to examine the $HOME/.ncftp/spool/log 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 `` @'' parameter, 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 background 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 background job when you close the site is that ncftp can pass
off that open connection to the ncftpbatch program. 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 translation 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 previ Äê
ously saved bookmark, 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 pro Äê
gram 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 messages between the program and the remote server, and things that are only printed in debugging
mode. However, 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.

edit Downloads into a temporary file for editing on the local host, then uploads the changed file back to the remote host.

get Copies files from the current working directory on the remote host to your machine's current working directory. 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 connection 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 kilo Äê
bytes, 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
`` f'' 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.

When using the `` R'' flag, you can also use the `` T'' flag to disable automatic on the fly TAR mode for downloading whole directory trees. The pro Äê
gram uses TAR whenever possible since this usually preserves symbolic links and file permissions. TAR mode can also result in faster transfers for
directories containing many small files, since a single data connection can be used rather than an FTP data connection for each small file. The down Äê
side to using TAR is that it forces downloading of the whole directory, even if you had previously downloaded a portion of it earlier, so you may want
to use this option if you want to resume downloading of a directory.

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 directory, 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 win Äê
dow. You can use the same flags with lls as you would in your command 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 preferred $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 permissions 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

Here is a list of options available for use with the open command:

u XX Use username XX instead of anonymous.

p XX Use password XX with the username.

j XX Use account XX in supplement to the username and password (deprecated).

P XX Use port number XX instead of the default FTP service port (21).

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 list Äê
ing 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 direc Äê
tory, 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 permis Äê
sions. 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 devnull@example.com

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 command 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 particular 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 variable 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 considers 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 protocol behavior is to use the FTP com Äê
mand 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 smallest 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 conve Äê
nient, 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 supports 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 on

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 configu Äê
ration 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/bookmarks
Saves bookmark and host information.

$HOME/.ncftp/firewall
Firewall access configuration file.

$HOME/.ncftp/prefs
Program preferences.

$HOME/.ncftp/trace
Debugging output for entire program run.

$HOME/.ncftp/v3init
Used to tell if this version of the program has run before.

$HOME/.ncftp/spool/
Directory where background jobs are stored in the form of spool configuration files.

$HOME/.ncftp/spool/log
Information for background data transfer processes.

ENVIRONMENT
PATH User's search path, used to find the ncftpbatch program, 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 Readli


Related Topics

Apt Get Commands