SYNOPSIS
ftp [-v] [-d] [-i] [-n] [-g] [-k realm] [-f] [-x] [-u] [-t] [host]
DESCRIPTION
FTP is the user interface to the ARPANET standard File Transfer Proto-
col. The program allows a user to transfer files to and from a remote
network site.
OPTIONS
Options may be specified at the command line, or to the command inter-
preter.
-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 con-
nection. 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.
-u Restrains ftp from attempting ``auto-authentication'' upon ini-
tial connection. If auto-authentication is enabled, ftp
attempts to authenticate to the FTP server by sending the AUTH
command, using whichever authentication types are locally sup-
ported. Once an authentication type is accepted, an authentica-
tion protocol will proceed by issuing ADAT commands. This
option also disables auto-login.
-i Turns off interactive prompting during multiple file transfers.
-d Enables debugging.
-g Disables file name globbing.
-f Causes credentials to be forwarded to the remote host.
-x Causes the client to attempt to negotiate encryption (data and
command protection levels ``private'') immediately after suc-
cessfully authenticating.
-t Enables packet tracing.
COMMANDS
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>''
pleted. 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 set-
ting. 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 file 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 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.
ccc Turn off integrity protection on the command channel. This com-
mand must be sent integrity protected, and must be proceeded by
a successful ADAT command. Since turning off integrity protec-
tion potentially allows an attacker to insert commands onto the
command channel, some FTP servers may refuse to honor this com-
mand.
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
system to mode.
clear Set the protection level on data transfers to ``clear''. If no
ADAT command succeeded, then this is the default protection
level.
close Terminate the FTP session with the remote server, and return to
the command interpreter. Any defined macros are erased.
cprotect [protection-level]
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 distin-
guished 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 file 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 glob-
bing 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 -' 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).
tory 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 sys-
tems 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.
macdefmacro-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 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 file-
name expansion. Resulting file names will then be processed
according to case, ntrans, and nmap settings. Files are trans-
ferred 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.
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 consid-
ered 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 tar-
get 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 non-UNIX remote computer with different file nam-
ing 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. Addi-
tionally, 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 file-
names "myfile.data" and "myfile.data.old", "myfile.file" for the
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 corre-
sponding 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] [-forward]
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-
authenticate option is on (default), ftp will attempt to authen-
ticate to the FTP server by sending the AUTH command, using
whichever authentication types which are locally supported.
Once an authentication type is accepted, an authentication pro-
tocol will proceed by issuing ADAT commands. If the auto-login
option is on (default), ftp will also attempt to automatically
log the user in to the FTP server (see below). If the -forward
option is specified, ftp will forward a copy of the user's Ker-
beros tickets to the remote host.
passive
Toggle passive data transfer mode. In passive mode, the client
initiates the data connection by listening on the data port.
Passive mode may be necessary for operation from behind fire-
walls which do not permit incoming connections.
private
Set 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 possi-
ble level is ``clear''.
prompt Toggle interactive prompting. Interactive prompting occurs dur-
ing 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.
protect [protection-level]
Set the protection level on data transfers to protection-level.
The valid protection levels are ``clear'' for unprotected data
transmissions, ``safe'' for data transmissions integrity pro-
tected by cryptographic checksum, and ``private'' for data
transmissions 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
Execute an ftp command on a secondary control connection. This
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 par-
tially transferred copy of remote-file and the transfer is con-
tinued from the apparent point of failure. This command is use-
ful 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.
If no ADAT command succeeded, then the only possible level is
``clear''.
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 com-
mands is disabled, no attempt will be made to use PORT commands
for each data transfer. This is useful for certain FTP imple-
mentations which do ignore PORT commands but, incorrectly, indi-
cate 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 speci-
fied, the current type is printed. The default type is network
ASCII.
umask [newmask]
Set the default umask on the remote server to newmask. If new-
mask is omitted, the current umask is printed.
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.
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 com-
pleted 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, 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
from (writes to) 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 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 file-
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 com-
mand functions. A macro is defined with the specified name; its
contents begin with the next .netrc line and continue until a
Lunt, S. J., FTP Security Extensions, Internet Draft, November 1993.
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 incor-
rect transfers of binary files to and from 4.2BSD servers using the
ascii type. Avoid this problem by using the binary image type.
FTP(1)
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