mode
FTP(1)
NAME
ftp - ARPANET file transfer program
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 Protocol. 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 interpreter.
-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 ââauto-loginââ upon initial connection. If auto-login is enabled, ftp will check the .netrc (see below) file in the
userâs 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 ââauto-authenticationââ upon initial 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 supported. Once an authentication type is accepted,
an authentication 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.
-k realm
When using Kerberos v4 authentication, gets tickets in realm.
-f Causes credentials to be forwarded to the remote host.
-x Causes the client to attempt to negotiate encryption (data and command protection levels ââprivateââ) immediately after successfully authenticat-
ing.
-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 con-
nection to an FTP server on that host; otherwise, ftp will enter its command interpreter and await instructions from the user. When ftp is awaiting com-
mands from the user the prompt ââftp>ââ 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 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 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.
ccc Turn off integrity protection on the command channel. This command must be sent integrity protected, and must be proceeded by a successful ADAT
command. Since turning off integrity protection potentially allows an attacker to insert commands onto the command channel, some FTP servers may
refuse to honor this command.
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 ââclearââ. 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]
Set the protection level on commands to protection-level. The valid protection levels are ââclearââ for unprotected commands, ââsafeââ for com-
mands integrity protected by cryptographic checksum, and ââprivateââ for commands confidentiality and integrity protected by encryption. If an
ADAT command succeeded, then the default command protection level is ââsafeââ, otherwise the only possible level is ââclearââ. If no level is
specified, the current level is printed. cprotect clear is equivalent to the ccc command.
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 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 com-
mand sent to the remote machine, preceded by the string â-->â
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 direc-
tory is specified, the current working directory on the remote machine is used. If no local file is specified, or local-file is â-â, output comes
to the terminal.
disconnect
A synonym for close.
form format
Set the file transfer form to format. The default format is ââfileââ.
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 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 âmls remote-files -â 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 (ââ#ââ) 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 userâs 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 âls -lâ. (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 â-â, 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 â$â and â\â as special characters. A â$â followed by a number (or num-
bers) is replaced by the corresponding argument on the macro invocation command line. A â$â followed by an âiâ signals that macro processor that
the executing macro is to be looped. On the first pass â$iâ 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 â\â followed by any character is replaced by that character. Use the â\â to prevent
special treatment of the â$â.
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 argu-
ment 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 âlcd directoryâ; new local directories can be created with â! mkdir directoryâ.
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 ââstreamââ 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 file-
name 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 out-
put. If no local file is specified, or if local-file is â-â, 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 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 â$1â, â$2â, ..., â$9â in inpattern. Use â\â to prevent this special treatment of
the â$â 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 outpat-
tern determines the resulting mapped filename. The sequences â$1â, â$2â, inpattern template. The sequence â$0â is replace by the original file-
name. Additionally, the sequence â[seq1, seq2]â is replaced by [seq1] if seq1 is not a null string; otherwise it is replaced by seq2. For exam-
ple, 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: ânmap $1 sed "s/ *$//" >
$1â. Use the â\â character to prevent special treatment of the â$â,â[â,â]â, and â,â 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 charac-
terâs 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 authenticate 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 protocol
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 userâs Kerberos tickets to the remote host.
passive
Toggle passive data transfer mode off. In passive mode, the client initiates the data connection by connecting to the data port. Passive mode is
often necessary for operation from behind firewalls which do not permit incoming connections, but may need to be disabled if you connect to an FTP
server which does not support passive operation.
private
Set the protection level on data transfers to ââprivateââ. Data transmissions are confidentiality and integrity protected by encryption. If no
ADAT command succeeded, then the only possible level is ââclearââ.
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.
protect [protection-level]
Set the protection level on data transfers to protection-level. The valid protection levels are ââclearââ for unprotected data transmissions,
ââsafeââ for data transmissions integrity protected by cryptographic checksum, and ââprivateââ for data transmissions confidentiality and
integrity protected by encryption. If no ADAT command succeeded, then the only possible level is ââclearââ. If no level is specified, the cur-
rent level is printed. The default protection level is ââclearââ.
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 pro-
tocol 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 follow-
ing 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.
safe Set the protection level on data transfers to ââsafeââ. Data transmissions are integrity-protected by cryptographic checksum. If no ADAT command
succeeded, then the only possible level is ââclearââ.
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 theyâve 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 ââstreamââ 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 com-
pletion. 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 ââauto-loginââ 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.
Command arguments which have embedded spaces may be quoted with quote â"â 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 serverâs support for ABOR processing. If the remote server does not support the ABOR command, an âftp>â 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 â-â is specified, stdin (for reading) or stdout (for writing) is used.
2. If the first character of the file name is â|â, 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. ââ" ls -lt"ââ. A particularly useful example of this mechanism is: ââdir moreââ.
3. Failing the above checks, if ââglobbingââ 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 ââglobbingââ 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 ââasciiââ, ââimageââ (binary), ââebcdicââ, and
ââlocal byte sizeââ (mostly for PDP-10âs and PDP-20âs). 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 userâs 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 utilizes the following environment variables.
HOME For default location of a .netrc file, if one exists.
SHELL For default shell.
SEE ALSO
ftpd(8)
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 incorrect trans-
fers of binary files to and from 4.2BSD servers using the ascii type. Avoid this problem by using the binary image type.