FTP(1)FTP(1)NAMEftp - file transfer program
SYNOPSISftp [-adfginpstvx] [-m GSS Mech] [-T timeout]
[hostname [port]]
DESCRIPTION
The ftp command is the user interface to the Internet standard File
Transfer Protocol (FTP). ftp transfers files to and from a remote net‐
work site.
The host and optional port with which ftp is to communicate can be
specified on the command line. If this is done, ftp immediately
attempts to establish a connection to an FTP server on that host. Oth‐
erwise, ftp enters its command interpreter and awaits instructions from
the user. When ftp is awaiting commands from the user, it displays the
prompt ftp>.
OPTIONS
The following options can be specified at the command line, or to the
command interpreter:
-a
Uses GSSAPI authentication only. If the authentication
fails, this option closes the connection.
-d
Enables debugging.
-f
Forwards local security credentials to the remote server.
-g
Disables filename "globbing".
-i
Turns off interactive prompting during multiple file
transfers.
-m
Specifies the GSS-API mechanism to use. The default is to
use the kerberos_v5 mechanism. Supported alternatives are
defined in /etc/gss/mech (see mech(4)).
-n
Does not attempt "auto-login" upon initial connection. If
auto-login is not disabled, ftp checks the .netrc file in
the user's home directory for an entry describing an
account on the remote machine. If no entry exists, ftp
prompts for the login name of the account on the remote
machine (the default is the login name on the local
machine), and, if necessary, prompts for a password and
an account with which to login.
-p
Enables passive mode for data transfers. This command is
useful when connecting to a remote host from behind a
connection filtering firewall.
-s
Skips the SYST command that is sent by default to all
remote servers upon connection. The system command is
what enables the automatic use of binary mode rather than
the protocol default ascii mode.
As some older servers cannot handle the ftp command, this
directive is provided to allow inter-operability with
these servers.
-t
Enables packet tracing (unimplemented).
-T timeout
Enables global connection timer, specified in seconds
(decimal). There is a timer for the control connection
that is reset when anything is sent to the server and
disabled while the client is prompting for user input.
Another independent timer is used to monitor incoming or
outgoing data connections.
-v
Shows all responses from the remote server, as well as
report on data transfer statistics. This is turned on by
default if ftp is running interactively with its input
coming from the user's terminal.
-x
Attempts to use GSSAPI for authentication and encryption.
Data and Command channel protection is set to "private".
The following commands can be specified to the command interpreter:
!
[ command ] Runs command as a shell command on the local machine.
If no command is given, invokes an interactive shell.
$ macro-name [ args ]
Executes the macro macro-name that was defined with the macdef com‐
mand. Arguments are passed to the macro unglobbed.
account [ passwd ]
Supplies a supplemental password required by a remote system for
access to resources once a login has been successfully completed.
If no argument is included, the user is prompted for an account
password in a non-echoing input mode.
append local-file [ remote-file ]
Appends a local file to a file on the remote machine. If remote-
file is not specified, the local file name is used, subject to
alteration by any ntrans or nmap settings. File transfer uses the
current settings for "representation type", "file structure", and
"transfer mode".
ascii
Sets the "representation type" to "network ASCII". This is the
default type.
bell
Sounds a bell after each file transfer command is completed.
binary
Sets the "representation type" to "image".
bye
Terminates the FTP session with the remote server and exit ftp. An
EOF also terminates the session and exit.
case
Toggles remote computer file name case mapping during mget com‐
mands. 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
Changes the working directory on the remote machine to remote-
directory.
cdup
Changes the remote machine working directory to the parent of the
current remote machine working directory.
clear
Sets the protection level on data transfers to "clear". If no ADAT
command succeeded, then this is the default protection level.
close
Terminates the FTP session with the remote server, and return to
the command interpreter. Any defined macros are erased.
cr
Toggles RETURN stripping during "network ASCII" type file
retrieval. Records are denoted by a RETURN/LINEFEED sequence dur‐
ing "network ASCII" type file transfer. When cr is on (the
default), RETURN characters are stripped from this sequence to con‐
form with the UNIX system single LINEFEED record delimiter. Records
on non-UNIX-system remote hosts can contain single LINEFEED charac‐
ters; when an "network ASCII" type transfer is made, these LINEFEED
characters can be distinguished from a record delimiter only when
cr is off.
delete remote-file
Deletes the file remote-file on the remote machine.
debug
Toggles debugging mode. When debugging is on, ftp prints each com‐
mand sent to the remote machine, preceded by the string ->.
dir [ remote-directory [ local-file ]]
Prints a listing of the directory contents in the directory,
remote-directory, and, optionally, placing the output in local-
file. 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 is sent to the terminal.
disconnect
A synonym for close.
form [ format-name ]
Sets the carriage control format subtype of the "representation
type" to format-name. The only valid format-name is non-print,
which corresponds to the default "non-print" subtype.
get remote-file [ local-file ]
Retrieves 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 "representation
type", "file structure", and "transfer mode" are used while trans‐
ferring the file.
glob
Toggles filename expansion, or "globbing", for mdelete, mget and
mput. If globbing is turned off, filenames are taken literally.
Globbing for mput is done as in sh(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 radically different
from expansion of the name of an ordinary file: the exact result
depends on the remote operating system and FTP server, and can be
previewed with the command, mls remote-files −.
mget and mput are not meant to transfer entire directory subtrees
of files. You can do this by transferring a tar(1) archive of the
subtree (using a "representation type" of "image" as set by the
binary command).
hash
Toggles hash-sign (#) printing for each data block transferred. The
size of a data block is 8192 bytes.
help [ command ]
Prints an informative message about the meaning of command. If no
argument is given, ftp prints a list of the known commands.
lcd [ directory ]
Changes the working directory on the local machine. If no directory
is specified, the user's home directory is used.
ls [ -al | remote-directory [ local-file ]]
By default, prints an abbreviated listing of the contents of a
directory on the remote machine. This default behavior can be
changed to make ls a synonym of the dir command. This change can be
achieved by setting FTP_LS_SENDS_NLST to 'no' in /etc/default/ftp
or in the environment. See ftp(4) for details.
The -a option lists all entries, including those that begin with a
dot (.), which are normally not listed. The -l option lists files
in long format, giving mode, number of links, owner, group, size in
bytes, and time of last modification for each file. If the file is
a special file, the size field instead contains the major and minor
device numbers rather than a size. If the file is a symbolic link,
the filename is printed followed by "→" and the pathname of the
referenced file.
If remote-directory is left unspecified, the current working direc‐
tory is used.
If no local file is specified, or if local-file is −, the output is
sent to the terminal.
macdef macro-name
Defines a macro. Subsequent lines are stored as the macro macro-
name. A null line (consecutive NEWLINE characters in a file or
RETURN characters 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 exe‐
cuted.
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 spe‐
cial treatment of the $.
mdelete remote-files
Deletes the remote-files on the remote machine.
mdir remote-files local-file
Like dir, except multiple remote files can be specified. If inter‐
active prompting is on, ftp prompts the user to verify that the
last argument is indeed the target local file for receiving mdir
output.
mget remote-files
Expands 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 are 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
Makes a directory on the remote machine.
mls remote-files local-file
Like ls(1), except multiple remote files can be specified. If
interactive prompting is on, ftp prompts the user to verify that
the last argument is indeed the target local file for receiving mls
output.
mode [ mode-name ]
Sets the "transfer mode" to mode-name. The only valid mode-name is
stream, which corresponds to the default "stream" mode. This imple‐
mentation only supports stream, and requires that it be specified.
mput local-files
Expands 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 are processed
according to ntrans and nmap settings.
nlist [ -al | remote-directory [ local-file ]]
Prints an abbreviated listing of the contents of a directory on the
remote machine, listing only those files that can be retrieved by
the get command, unless the -a or -l option is used. If remote-
directory is left unspecified, the current working directory is
used.
The -a option lists all entries, including those that begin with a
dot (.), which are normally not listed. The -l option lists files
in long format the same way it does when used with the ls command.
nmap [ inpattern outpattern ]
Sets or unsets 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-system remote
host with different file naming conventions or practices. The map‐
ping follows the pattern set by inpattern and outpattern. inpattern
is a template for incoming filenames (which can have already been
processed according to the ntrans and case settings). Variable tem‐
plating 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 replaced 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. SPACE
characters can be included in outpattern, as in the example nmap $1
| sed "s/ *$//" > $1. Use the \ character to prevent special treat‐
ment of the $, [, ], and ,, characters.
ntrans [ inchars [ outchars ] ]
Sets or unsets the filename character translation mechanism. If no
arguments are specified, the filename character translation mecha‐
nism 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, and characters
in local filenames are translated during mget commands and get com‐
mands issued without a specified local target filename.
This command is useful when connecting to a non-UNIX-system remote
host with different file naming conventions or practices. Charac‐
ters 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.
Only 16 characters can be translated when using the ntrans command
under ftp. Use case (described above) if needing to convert the
entire alphabet.
open host [ port ]
Establishes a connection to the specified host FTP server. An
optional port number can be supplied, in which case, ftp attempts
to contact an FTP server at that port. If the auto-login option is
on (default setting), ftp also attempts to automatically log the
user in to the FTP server.
passive
Toggles passive mode. When passive mode is turned on, the ftp
client sends the PASV command requesting that the FTP 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 passive mode is turned off, the ftp client sends the PORT
command to the server specifying an address for the remote server
to connect back to. Passive mode is useful when the connections to
the ftp client are controlled, for example, when behind a firewall.
When connecting to an IPv6-enabled FTP server, EPSV can be used in
place of PASV and EPRT in place of PORT.
private
Sets the protection level on data transfers to "private". Data
transmissions are confidentiality— and integrity—protected by
encryption. If no ADAT command succeeded, then the only possible
level is "clear".
prompt
Toggles interactive prompting. Interactive prompting occurs during
multiple file transfers to allow the user to selectively retrieve
or store files. By default, prompting is turned on. If prompting is
turned off, any mget or mput transfers all files, and any mdelete
deletes all files.
protect protection-level
Sets the protection level on data transfers to protection-level.
The valid protection levels are "clear" for unprotected data trans‐
missions, "safe" for data transmissions that are integrity-pro‐
tected by cryptographic checksum, and "private" for data transmis‐
sions that are confidentiality— and integrity— protected by encryp‐
tion. If no ADAT command succeeded, then the only possible level is
"clear". If no level is specified, the current level is printed.
The default protection level is "clear".
proxy ftp-command
Executes 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 con‐
nection. Enter the command proxy ? to see other FTP commands exe‐
cutable on the secondary connection.
The following commands behave differently when prefaced by proxy:
open does not define new macros during the auto-login process,
close does 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, mputd, and
append transfer files from the host on the secondary control con‐
nection to the host on the primary control connection.
Third party file transfers depend upon support of the PASV command
by the server on the secondary control connection.
put local-file [ remote-file ]
Stores 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 "representation type", "file
structure", and "transfer mode".
pwd
Prints the name of the current working directory on the remote
machine.
quit
A synonym for bye.
quote arg1 arg2 ...
Sends the arguments specified, verbatim, to the remote FTP server.
A single FTP reply code is expected in return. (The remotehelp com‐
mand displays a list of valid arguments.)
quote should be used only by experienced users who are familiar
with the FTP protocol.
recv remote-file [ local-file ]
A synonym for get.
reget remote-file [ local-file ]
The reget command 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 con‐
tinued from the apparent point of failure. This command is useful
when transferring large files over networks that are prone to drop‐
ping connections.
remotehelp [ command-name ]
Requests help from the remote FTP server. If a command-name is
specified it is supplied to the server as well.
rename from to
Renames the file from on the remote machine to have the name to.
reset
Clears reply queue. This command re-synchronizes command/reply
sequencing with the remote FTP server. Resynchronization can be
necessary following a violation of the FTP protocol by the remote
server.
restart [ marker ]
Restarts the immediately following get or put at the indicated
marker. On UNIX systems, marker is usually a byte offset into the
file. When followed by an mget, the restart applies to the first
get performed. Specifying a marker of 0 clears the restart marker.
If no argument is specified, the current restart status is dis‐
played.
rmdir directory-name
Deletes a directory on the remote machine.
runique
Toggles 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 is reported. runique does not affect
local files generated from a shell command. The default value is
off.
safe
Sets the protection level on data transfers to "safe". Data trans‐
missions are integrity-protected by cryptographic checksum. If no
ADAT command succeeded, then the only possible level is "clear".
send local-file [ remote-file ]
A synonym for put.
sendport
Toggles the use of PORT commands. By default, ftp attempts to use a
PORT command when establishing a connection for each data transfer.
The use of PORT commands can prevent delays when performing multi‐
ple file transfers. If the PORT command fails, ftp uses the default
data port. When the use of PORT commands is disabled, no attempt is
made to use PORT commands for each data transfer. This is useful
when connected to certain FTP implementations that ignore PORT com‐
mands but incorrectly indicate they have been accepted.
site arg1 [ arg2 ] ...
Sends the arguments specified, verbatim, to the remote FTP server
as a SITE command.
status
Show the current status of ftp.
struct [ struct-name ]
Sets the file structure to struct-name. The only valid struct-name
is file, which corresponds to the default "file" structure. The
implementation only supports file, and requires that it be speci‐
fied.
sunique
Toggles storing of files on remote machine under unique file names.
The remote FTP server must support the STOU command for successful
completion. The remote server reports the unique name. Default
value is off.
tcpwindow [ size ]
Sets the TCP window size to be used for data connections. Specify‐
ing a size of 0 stops the explicit setting of the TCP window size
on data connections. If no argument is specified, the current set‐
ting is displayed.
tenex
Sets the "representation type" to that needed to talk to TENEX
machines.
trace
Toggles packet tracing (unimplemented).
type [ type-name ]
Sets the "representation type" to type-name. The valid type-names
are ascii for "network ASCII", binary or image for "image", and
tenex for "local byte size" with a byte size of 8 (used to talk to
TENEX machines). If no type is specified, the current type is
printed. The default type is "network ASCII".
user user-name [ password [ account ]]
Identify yourself to the remote FTP server. If the password is not
specified and the server requires it, ftp prompts the user for it
(after disabling local echo). If an account field is not specified,
and the FTP server requires it, the user is prompted for it. If an
account field is specified, an account command is 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
Toggles verbose mode. In verbose mode, all responses from the FTP
server are displayed to the user. In addition, if verbose mode is
on, when a file transfer completes, statistics regarding the effi‐
ciency of the transfer are reported. By default, verbose mode is on
if ftp's commands are coming from a terminal, and off otherwise.
? [ command ]
A synonym for help.
Command arguments which have embedded spaces can be quoted with quote
(") marks.
If any command argument which is not indicated as being optional is not
specified, ftp prompts for that argument.
ABORTING A FILE TRANSFER
To abort a file transfer, use the terminal interrupt key. Sending
transfers is immediately halted. Receiving transfers are halted by
sending an FTP protocol ABOR command to the remote server, and discard‐
ing 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 does
not appear until the remote server has completed sending the requested
file.
The terminal interrupt key sequence is ignored when ftp has completed
any local processing and is awaiting a reply from the remote server. A
long delay in this mode can result from the ABOR processing described
above, or from unexpected behavior by the remote server, including vio‐
lations 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
Local files specified as arguments to ftp commands are processed
according to the following rules.
1)
If the file name − is specified, the standard input (for reading)
or standard output (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(3C) with the argument supplied, and reads
(writes) from the standard output (standard input) of that shell.
If the shell command includes SPACE characters, the argument must
be quoted; for example "| 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 sh(1); see
the glob command. If the ftp command expects a single local file
(for example, 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 can be
altered by a case, ntrans, or nmap setting. The resulting file‐
name can 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 can be
altered by a ntrans or nmap setting. The resulting filename can
then be altered by the remote server if sunique is on.
FILE TRANSFER PARAMETERS
The FTP specification specifies many parameters which can affect a file
transfer.
The "representation type" can be one of "network ASCII", "EBCDIC",
"image", or "local byte size" with a specified byte size (for PDP-10's
and PDP-20's mostly). The "network ASCII" and "EBCDIC" types have a
further subtype which specifies whether vertical format control (NEW‐
LINE characters, form feeds, and so on) are to be passed through ("non-
print"), provided in TELNET format ("TELNET format controls"), or pro‐
vided in ASA (FORTRAN) ("carriage control (ASA)") format. ftp supports
the "network ASCII" (subtype "non-print" only) and "image" types, plus
"local byte size" with a byte size of 8 for communicating with TENEX
machines.
The "file structure" can be one of file (no record structure), record,
or page. ftp supports only the default value, which is file.
The "transfer mode" can be one of stream, block, or compressed. ftp
supports only the default value, which is stream.
USAGE
See largefile(5) for the description of the behavior of ftp when
encountering files greater than or equal to 2 Gbyte (2^31 bytes).
The ftp command is IPv6-enabled. See ip6(7P).
FILES
~/.netrc
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌───────────────┬─────────────────┐
│ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├───────────────┼─────────────────┤
│CSI │ enabled │
└───────────────┴─────────────────┘
SEE ALSOls(1), rcp(1), sh(1), tar(1), in.ftpd(1M), popen(3C), ftp(4),
ftpusers(4), mech(4), netrc(4), attributes(5), largefile(5), ip6(7P)
Allman, M., Ostermann, S., and Metz, C. RFC 2428, FTP Extensions for
IPv6 and NATs. The Internet Society. September 1998.
Lunt, S. J. RFC 2228, FTP Security Extensions. Internet Draft. November
1993.
Postel, Jon, and Joyce Reynolds. RFC 959, File Transfer Protocol (FTP
). Network Information Center. October 1985.
Piscitello, D. RFC 1639, FTP Operation Over Big Address Records (FOO‐
BAR). Network Working Group. June 1994.
NOTES
Failure to log in can arise from an explicit denial by the remote FTP
server because the account is listed in /etc/ftpusers. See in.ftpd(1M)
and ftpusers(4).
Correct execution of many commands depends upon proper behavior by the
remote server.
An error in the treatment of carriage returns in the 4.2 BSD code han‐
dling transfers with a "representation type" of "network ASCII" has
been corrected. This correction can result in incorrect transfers of
binary files to and from 4.2 BSD servers using a "representation type"
of "network ASCII". Avoid this problem by using the "image" type.
Jun 6, 2006 FTP(1)