NAME
ftp - ARPANET file transfer program
SYNOPSIS
ftp [-K] [-d] [-g] [-i] [-l] [-n] [-p] [-t] [-v] [-x] [--no-gss-bindings]
[--no-gss-delegate] [host]
DESCRIPTION
ftp is the user interface to the ARPANET standard File Transfer Protocol.
The program allows a user to transfer files to and from a remote network
site.
Modifications have been made so that it almost follows the FTP Security
Extensions, RFC 2228.
Options may be specified at the command line, or to the command
interpreter.
-K Disable Kerberos authentication.
-t Enables packet tracing.
-v Verbose option forces ftp to show all responses from the remote
server, as well as report on data transfer statistics.
-n Restrains ftp from attempting “auto-login” upon initial connection.
If auto-login is enabled, ftp will check the .netrc (see below)
file in the user’s home directory for an entry describing an
account on the remote machine. If no entry exists, ftp will prompt
for the remote machine login name (default is the user identity on
the local machine), and, if necessary, prompt for a password and an
account with which to login.
-i Turns off interactive prompting during multiple file transfers.
-p Turn on passive mode.
-d Enables debugging.
-g Disables file name globbing.
.It Fl -no-gss-bindings Don’t use GSS-API bindings when talking to
peer. IP addresses will not be checked to ensure they match.
--no-gss-delegate
Disable delegation of GSSAPI credentials.
-l Disables command line editing.
-x Encrypt command and data channel.
The client host with which ftp is to communicate may be specified on the
command line. If this is done, ftp will immediately attempt to establish
a connection to an FTP server on that host; otherwise, ftp will enter its
command interpreter and await instructions from the user. When ftp is
awaiting commands from the user the prompt ‘ftp>’ is provided to the
user. The following commands are recognized by ftp:
! [command [args]]
Invoke an interactive shell on the local machine. If there
are arguments, the first is taken to be a command to execute
directly, with the rest of the arguments as its arguments.
$ macro-name [args]
Execute the macro macro-name that was defined with the macdef
command. Arguments are passed to the macro unglobbed.
account [passwd]
Supply 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 will be
prompted for an account password in a non-echoing input mode.
append local-file [remote-file]
Append a local file to a file on the remote machine. If
remote-file is left unspecified, the local file name is used
in naming the remote file after being altered by any ntrans
or nmap setting. File transfer uses the current settings for
type, format, mode, and structure.
ascii Set the file transfer type to network ASCII. This is the
default type.
bell Arrange that a bell be sounded after each file transfer
command is completed.
binary Set the file transfer type to support binary image transfer.
bye Terminate the FTP session with the remote server and exit
ftp. An end of file will also terminate the session and
exit.
case Toggle remote computer file name case mapping during mget
commands. When case is on (default is off), remote computer
file names with all letters in upper case are written in the
local directory with the letters mapped to lower case.
cd remote-directory
Change the working directory on the remote machine to
remote-directory.
cdup Change the remote machine working directory to the parent of
the current remote machine working directory.
chmod mode file-name
Change the permission modes of the file file-name on the
remote sytem to mode.
close Terminate the FTP session with the remote server, and return
to the command interpreter. Any defined macros are erased.
cr Toggle carriage return stripping during ascii type file
retrieval. Records are denoted by a carriage return/linefeed
sequence during ascii type file transfer. When cr is on (the
default), carriage returns are stripped from this sequence to
conform with the UNIX single linefeed record delimiter.
Records on non-UNIX remote systems may contain single
linefeeds; when an ascii type transfer is made, these
linefeeds may be distinguished from a record delimiter only
when cr is off.
delete remote-file
Delete the file remote-file on the remote machine.
debug [debug-value]
Toggle debugging mode. If an optional debug-value is
specified it is used to set the debugging level. When
debugging is on, ftp prints each command sent to the remote
machine, preceded by the string ‘-->’
dir [remote-directory] [local-file]
Print a listing of the directory contents in the directory,
remote-directory, and, optionally, placing the output in
local-file. If interactive prompting is on, ftp will prompt
the user to verify that the last argument is indeed the
target local file for receiving dir output. If no directory
is specified, the current working directory on the remote
machine is used. If no local file is specified, or
local-file is -, output comes to the terminal.
disconnect A synonym for close.
form format
Set the file transfer form to format. The default format is
“file”.
get remote-file [local-file]
Retrieve the remote-file and store it on the local machine.
If the local file name is not specified, it is given the same
name it has on the remote machine, subject to alteration by
the current case, ntrans, and nmap settings. The current
settings for type, form, mode, and structure are used while
transferring the file.
glob Toggle filename expansion for mdelete, mget and mput. If
globbing is turned off with glob, the file name arguments are
taken literally and not expanded. Globbing for mput is done
as in csh(1). For mdelete and mget, each remote file name is
expanded separately on the remote machine and the lists are
not merged. Expansion of a directory name is likely to be
different from expansion of the name of an ordinary file: the
exact result depends on the foreign operating system and ftp
server, and can be previewed by doing ‘mls remote-files -’.
As a security measure, remotely globbed files that starts
with ‘/’ or contains ‘../’, will not be automatically
received. If you have interactive prompting turned off, these
filenames will be ignored. Note: mget and mput are not meant
to transfer entire directory subtrees of files. That can be
done by transferring a tar(1) archive of the subtree (in
binary mode).
hash Toggle hash-sign (‘‘#’’) printing for each data block
transferred. The size of a data block is 1024 bytes.
help [command]
Print an informative message about the meaning of command.
If no argument is given, ftp prints a list of the known
commands.
idle [seconds]
Set the inactivity timer on the remote server to seconds
seconds. If seconds is omitted, the current inactivity timer
is printed.
lcd [directory]
Change the working directory on the local machine. If no
directory is specified, the user’s home directory is used.
ls [remote-directory] [local-file]
Print a listing of the contents of a directory on the remote
machine. The listing includes any system-dependent
information that the server chooses to include; for example,
most UNIX systems will produce output from the command ‘ls
-l’. (See also nlist.) If remote-directory is left
unspecified, the current working directory is used. If
interactive prompting is on, ftp will prompt the user to
verify that the last argument is indeed the target local file
for receiving ls output. If no local file is specified, or
if local-file is ‘-’, the output is sent to the terminal.
macdef macro-name
Define a macro. Subsequent lines are stored as the macro
macro-name; a null line (consecutive newline characters in a
file or carriage returns from the terminal) terminates macro
input mode. There is a limit of 16 macros and 4096 total
characters in all defined macros. Macros remain defined
until a close command is executed. The macro processor
interprets ‘$’ and ‘\’ as special characters. A ‘$’ followed
by a number (or numbers) is replaced by the corresponding
argument on the macro invocation command line. A ‘$’
followed by an ‘i’ signals that macro processor that the
executing macro is to be looped. On the first pass ‘$i’ is
replaced by the first argument on the macro invocation
command line, on the second pass it is replaced by the second
argument, and so on. A ‘\’ followed by any character is
replaced by that character. Use the ‘\’ to prevent special
treatment of the ‘$’.
mdelete [remote-files]
Delete the remote-files on the remote machine.
mdir remote-files local-file
Like dir, except multiple remote files may be specified. If
interactive prompting is on, ftp will prompt the user to
verify that the last argument is indeed the target local file
for receiving mdir output.
mget remote-files
Expand the remote-files on the remote machine and do a get
for each file name thus produced. See glob for details on
the filename expansion. Resulting file names will then be
processed according to case, ntrans, and nmap settings.
Files are transferred into the local working directory, which
can be changed with ‘lcd directory’; new local directories
can be created with ‘! mkdir directory’.
mkdir directory-name
Make a directory on the remote machine.
mls remote-files local-file
Like nlist, except multiple remote files may be specified,
and the local-file must be specified. If interactive
prompting is on, ftp will prompt the user to verify that the
last argument is indeed the target local file for receiving
mls output.
mode [mode-name]
Set the file transfer mode to mode-name. The default mode is
“stream” mode.
modtime file-name
Show the last modification time of the file on the remote
machine.
mput local-files
Expand wild cards in the list of local files given as
arguments and do a put for each file in the resulting list.
See glob for details of filename expansion. Resulting file
names will then be processed according to ntrans and nmap
settings.
newer file-name
Get the file only if the modification time of the remote file
is more recent that the file on the current system. If the
file does not exist on the current system, the remote file is
considered newer. Otherwise, this command is identical to
get.
nlist [remote-directory] [local-file]
Print a list of the files in a directory on the remote
machine. If remote-directory is left unspecified, the
current working directory is used. If interactive prompting
is on, ftp will prompt the user to verify that the last
argument is indeed the target local file for receiving nlist
output. If no local file is specified, or if local-file is
-, the output is sent to the terminal.
nmap [inpattern outpattern]
Set or unset the filename mapping mechanism. If no arguments
are specified, the filename mapping mechanism is unset. If
arguments are specified, remote filenames are mapped during
mput commands and put commands issued without a specified
remote target filename. If arguments are specified, local
filenames are mapped during mget commands and get commands
issued without a specified local target filename. This
command is useful when connecting to a non-UNIX remote
computer with different file naming conventions or practices.
The mapping follows the pattern set by inpattern and
outpattern. [Inpattern] is a template for incoming filenames
(which may have already been processed according to the
ntrans and case settings). Variable templating is
accomplished by including the sequences ‘$1’, ‘$2’, ..., ‘$9’
in inpattern. Use ‘\’ to prevent this special treatment of
the ‘$’ character. All other characters are treated
literally, and are used to determine the nmap [inpattern]
variable values. For example, given inpattern $1.$2 and the
remote file name "mydata.data", $1 would have the value
"mydata", and $2 would have the value "data". The outpattern
determines the resulting mapped filename. The sequences
‘$1’, ‘$2’, ...., ‘$9’ are replaced by any value resulting
from the inpattern template. The sequence ‘$0’ is replace by
the original filename. Additionally, the sequence ‘[seq1,
seq2]’ is replaced by [seq1] if seq1 is not a null string;
otherwise it is replaced by seq2. For example, the command
nmap $1.$2.$3 [$1,$2].[$2,file]
would yield the output filename "myfile.data" for input
filenames "myfile.data" and "myfile.data.old", "myfile.file"
for the input filename "myfile", and "myfile.myfile" for the
input filename ".myfile". Spaces may be included in
outpattern, as in the example: ‘nmap $1 sed "s/ *$//" > $1’
. Use the ‘\’ character to prevent special treatment of the
‘$’,’[’,’[’, and ‘,’ characters.
ntrans [inchars [outchars]]
Set or unset the filename character translation mechanism.
If no arguments are specified, the filename character
translation mechanism is unset. If arguments are specified,
characters in remote filenames are translated during mput
commands and put commands issued without a specified remote
target filename. If arguments are specified, characters in
local filenames are translated during mget commands and get
commands issued without a specified local target filename.
This command is useful when connecting to a non-UNIX remote
computer with different file naming conventions or practices.
Characters in a filename matching a character in inchars are
replaced with the corresponding character in outchars. If
the character’s position in inchars is longer than the length
of outchars, the character is deleted from the file name.
open host [port]
Establish a connection to the specified host FTP server. An
optional port number may be supplied, in which case, ftp will
attempt to contact an FTP server at that port. If the
auto-login option is on (default), ftp will also attempt to
automatically log the user in to the FTP server (see below).
passive Toggle passive mode. If passive mode is turned on (default
is off), the ftp client will send a PASV command for all data
connections instead of the usual PORT command. The PASV
command requests that the remote server open a port for the
data connection and return the address of that port. The
remote server listens on that port and the client connects to
it. When using the more traditional PORT command, the client
listens on a port and sends that address to the remote
server, who connects back to it. Passive mode is useful when
using ftp through a gateway router or host that controls the
directionality of traffic. (Note that though ftp servers are
required to support the PASV command by RFC 1123, some do
not.)
prompt Toggle interactive prompting. Interactive prompting occurs
during multiple file transfers to allow the user to
selectively retrieve or store files. If prompting is turned
off (default is on), any mget or mput will transfer all
files, and any mdelete will delete all files.
proxy ftp-command
Execute an ftp command on a secondary control connection.
This command allows simultaneous connection to two remote ftp
servers for transferring files between the two servers. The
first proxy command should be an open, to establish the
secondary control connection. Enter the command "proxy ?" to
see other ftp commands executable on the secondary
connection. The following commands behave differently when
prefaced by proxy: open will not define new macros during the
auto-login process, close will not erase existing macro
definitions, get and mget transfer files from the host on the
primary control connection to the host on the secondary
control connection, and put, mput, and append transfer files
from the host on the secondary control connection to the host
on the primary control connection. Third party file
transfers depend upon support of the ftp protocol PASV
command by the server on the secondary control connection.
put local-file [remote-file]
Store a local file on the remote machine. If remote-file is
left unspecified, the local file name is used after
processing according to any ntrans or nmap settings in naming
the remote file. File transfer uses the current settings for
type, format, mode, and structure.
pwd Print the name of the current working directory on the remote
machine.
quit A synonym for bye.
quote arg1 arg2 ...
The arguments specified are sent, verbatim, to the remote FTP
server.
recv remote-file [local-file]
A synonym for get.
reget remote-file [local-file]
Reget acts like get, except that if local-file exists and is
smaller than remote-file, local-file is presumed to be a
partially transferred copy of remote-file and the transfer is
continued from the apparent point of failure. This command
is useful when transferring very large files over networks
that are prone to dropping connections.
remotehelp [command-name]
Request help from the remote FTP server. If a command-name
is specified it is supplied to the server as well.
remotestatus [file-name]
With no arguments, show status of remote machine. If
file-name is specified, show status of file-name on remote
machine.
rename [from] [to]
Rename the file from on the remote machine, to the file to.
reset Clear reply queue. This command re-synchronizes
command/reply sequencing with the remote ftp server.
Resynchronization may be necessary following a violation of
the ftp protocol by the remote server.
restart marker
Restart the immediately following get or put at the indicated
marker. On UNIX systems, marker is usually a byte offset
into the file.
rmdir directory-name
Delete a directory on the remote machine.
runique Toggle storing of files on the local system with unique
filenames. If a file already exists with a name equal to the
target local filename for a get or mget command, a ".1" is
appended to the name. If the resulting name matches another
existing file, a ".2" is appended to the original name. If
this process continues up to ".99", an error message is
printed, and the transfer does not take place. The generated
unique filename will be reported. Note that runique will not
affect local files generated from a shell command (see
below). The default value is off.
send local-file [remote-file]
A synonym for put.
sendport Toggle the use of PORT commands. By default, ftp will
attempt to use a PORT command when establishing a connection
for each data transfer. The use of PORT commands can prevent
delays when performing multiple file transfers. If the PORT
command fails, ftp will use the default data port. When the
use of PORT commands is disabled, no attempt will be made to
use PORT commands for each data transfer. This is useful for
certain FTP implementations which do ignore PORT commands
but, incorrectly, indicate they’ve been accepted.
site arg1 arg2 ...
The arguments specified are sent, verbatim, to the remote FTP
server as a SITE command.
size file-name
Return size of file-name on remote machine.
status Show the current status of ftp.
struct [struct-name]
Set the file transfer structure to struct-name. By default
“stream” structure is used.
sunique Toggle storing of files on remote machine under unique file
names. Remote ftp server must support ftp protocol STOU
command for successful completion. The remote server will
report unique name. Default value is off.
system Show the type of operating system running on the remote
machine.
tenex Set the file transfer type to that needed to talk to TENEX
machines.
trace Toggle packet tracing.
type [type-name]
Set the file transfer type to type-name. If no type is
specified, the current type is printed. The default type is
network ASCII.
umask [newmask]
Set the default umask on the remote server to newmask. If
newmask is omitted, the current umask is printed.
user user-name [password] [account]
Identify yourself to the remote FTP server. If the password
is not specified and the server requires it, ftp will prompt
the user for it (after disabling local echo). If an account
field is not specified, and the FTP server requires it, the
user will be prompted for it. If an account field is
specified, an account command will be relayed to the remote
server after the login sequence is completed if the remote
server did not require it for logging in. Unless ftp is
invoked with “auto-login” disabled, this process is done
automatically on initial connection to the FTP server.
verbose Toggle verbose mode. In verbose mode, all responses from the
FTP server are displayed to the user. In addition, if
verbose is on, when a file transfer completes, statistics
regarding the efficiency of the transfer are reported. By
default, verbose is on.
? [command]
A synonym for help.
The following command can be used with ftpsec-aware servers.
prot clear | safe | confidential | private
Set the data protection level to the requested level.
The following command can be used with ftp servers that has implemented
the KAUTH site command.
kauth [principal]
Obtain remote tickets.
Command arguments which have embedded spaces may be quoted with quote ‘"’
marks.
ABORTING A FILE TRANSFER
To abort a file transfer, use the terminal interrupt key (usually Ctrl-
C). Sending transfers will be immediately halted. Receiving transfers
will be halted by sending a ftp protocol ABOR command to the remote
server, and discarding any further data received. The speed at which
this is accomplished depends upon the remote server’s support for ABOR
processing. If the remote server does not support the ABOR command, an
‘ftp>’ prompt will not appear until the remote server has completed
sending the requested file.
The terminal interrupt key sequence will be ignored when ftp has
completed any local processing and is awaiting a reply from the remote
server. A long delay in this mode may result from the ABOR processing
described above, or from unexpected behavior by the remote server,
including violations of the ftp protocol. If the delay results from
unexpected remote server behavior, the local ftp program must be killed
by hand.
FILE NAMING CONVENTIONS
Files specified as arguments to ftp commands are processed according to
the following rules.
1. If the file name ‘-’ is specified, the stdin (for reading) or stdout
(for writing) is used.
2. If the first character of the file name is ‘|’, the remainder of the
argument is interpreted as a shell command. Ftp then forks a shell,
using popen(3) with the argument supplied, and reads (writes) from
the stdout (stdin). If the shell command includes spaces, the
argument must be quoted; e.g. “" ls -lt"”. A particularly useful
example of this mechanism is: “dir more”.
3. Failing the above checks, if ‘‘globbing’’ is enabled, local file
names are expanded according to the rules used in the csh(1); c.f.
the glob command. If the ftp command expects a single local file
(.e.g. put), only the first filename generated by the "globbing"
operation is used.
4. For mget commands and get commands with unspecified local file
names, the local filename is the remote filename, which may be
altered by a case, ntrans, or nmap setting. The resulting filename
may then be altered if runique is on.
5. For mput commands and put commands with unspecified remote file
names, the remote filename is the local filename, which may be
altered by a ntrans or nmap setting. The resulting filename may
then be altered by the remote server if sunique is on.
FILE TRANSFER PARAMETERS
The FTP specification specifies many parameters which may affect a file
transfer. The type may be one of “ascii”, “image” (binary), “ebcdic”,
and “local byte size” (for PDP-10’s and PDP-20’s mostly). Ftp supports
the ascii and image types of file transfer, plus local byte size 8 for
tenex mode transfers.
Ftp supports only the default values for the remaining file transfer
parameters: mode, form, and struct.
THE .netrc FILE
The .netrc file contains login and initialization information used by the
auto-login process. It resides in the user’s home directory. The
following tokens are recognized; they may be separated by spaces, tabs,
or new-lines:
machine name
Identify a remote machine name. The auto-login process
searches the .netrc file for a machine token that matches the
remote machine specified on the ftp command line or as an open
command argument. Once a match is made, the subsequent .netrc
tokens are processed, stopping when the end of file is reached
or another machine or a default token is encountered.
default This is the same as machine name except that default matches
any name. There can be only one default token, and it must be
after all machine tokens. This is normally used as:
default login anonymous password user@site
thereby giving the user automatic anonymous ftp login to
machines not specified in .netrc. This can be overridden by
using the -n flag to disable auto-login.
login name
Identify a user on the remote machine. If this token is
present, the auto-login process will initiate a login using the
specified name.
password string
Supply a password. If this token is present, the auto-login
process will supply the specified string if the remote server
requires a password as part of the login process. Note that if
this token is present in the .netrc file for any user other
than anonymous, ftp will abort the auto-login process if the
.netrc is readable by anyone besides the user.
account string
Supply an additional account password. If this token is
present, the auto-login process will supply the specified
string if the remote server requires an additional account
password, or the auto-login process will initiate an ACCT
command if it does not.
macdef name
Define a macro. This token functions like the ftp macdef
command functions. A macro is defined with the specified name;
its contents begin with the next .netrc line and continue until
a null line (consecutive new-line characters) is encountered.
If a macro named init is defined, it is automatically executed
as the last step in the auto-login process.
ENVIRONMENT
Ftp uses the following environment variables.
HOME For default location of a .netrc file, if one exists.
SHELL For default shell.
SEE ALSO
ftpd(8)
RFC2228.
HISTORY
The ftp command appeared in 4.2BSD.
BUGS
Correct execution of many commands depends upon proper behavior by the
remote server.
An error in the treatment of carriage returns in the 4.2BSD ascii-mode
transfer code has been corrected. This correction may result in
incorrect transfers of binary files to and from 4.2BSD servers using the
ascii type. Avoid this problem by using the binary image type.