NAME¶
ftp —
Internet file transfer
program
SYNOPSIS¶
ftp |
[-46pinegvd]
[host
[port]] |
pftp |
[-46inegvd]
[host
[port]] |
DESCRIPTION¶
Ftp is the user interface to the Internet standard File
Transfer Protocol. The program allows a user to transfer files to and from a
remote network site.
Options may be specified at the command line, or to the command interpreter.
- -4
- Use only IPv4 to contact any host.
- -6
- Use IPv6 only.
- -p
- Use passive mode for data transfers. Allows use of ftp in
environments where a firewall prevents connections from the outside world
back to the client machine. Requires that the ftp server support the PASV
command. This is the default if invoked as pftp.
- -i
- Turns off interactive prompting during multiple file
transfers.
- -n
- Restrains ftp from attempting
“auto-login” upon initial connection. If auto-login is
enabled, ftp will check the .netrc
(see netrc(5)) 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.
- -e
- Disables command editing and history support, if it was
compiled into the ftp executable. Otherwise, does
nothing.
- -g
- Disables file name globbing.
- -v
- Verbose option forces ftp to show all
responses from the remote server, as well as report on data transfer
statistics.
- -d
- Enables debugging.
The client host and an optional port number 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.
- qc
- Toggle the printing of control characters in the output of
ASCII type commands. When this is turned on, control characters are
replaced with a question mark if the output file is the standard output.
This is the default when the standard output is a tty.
- 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 -
’ 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.
- ipany
- Allow the address resolver to return any address
family.
- ipv4
- Restrict the address resolver to look only for IPv4
addresses.
- ipv6
- Restrict host adressing to IPv6 only.
- 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
[local-file]
- 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).
- 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. If local-file does not
exist ftp won't fetch the file. 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.
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.
- If the file name ‘-’ is
specified, the stdin (for reading) or
stdout (for writing) is used.
- 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”.
- 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.
- 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.
- 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.
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),
netrc(5), RFC 959
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.