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.TH FTPFS 4

.SH NAME

ftpfs  \- file transfer protocol (FTP) file system

.SH SYNOPSIS

.B ftpfs

[

.B -/dqnt

]

[

.B -m

.I mountpoint

]

[

.B -a

.I password

]

[

.B -e

.I ext

]

[

.B -k

.I keyspec

]

[

.B -o

.I os

]

[

.B -r

remoteroot

]

.I system

.SH DESCRIPTION

.I Ftpfs

dials the TCP file transfer protocol (FTP) port, 21, on

.I system

and mounts itself (see

.IR bind (2))

on

.I mountpoint

(default

.BR /n/ftp )

to provide access via FTP to files on the remote machine.

.I Ftpfs

attempts to use FTP's `passive' mode

but falls back to using `active' mode if that fails.

If required by the remote machine,

.I ftpfs

will ask

.IR factotum (4)

for a key matching the pattern

.IP

.EX

proto=pass service=ftp server=\fIsystem\fP user? !password? \fIkeyspec\fP

.EE

.PP

(If

.I factotum

does not have such a key,

.I factotum

will prompt the user for one.)

.PP

The user names

.B ftp

and

.B anonymous

conventionally offer guest/read-only access to

machines.

Anonymous FTP may be called without using factotum

by using the

.B -a

option and specifying the

.IR password .

.PP

By default the file seen at the mount point is the user's

remote home directory if he has one.

The option

.B -/

forces the mount point to correspond to the

remote root.

The option

.B -r

forces the mount point to correspond to the

remote directory

.IR remoteroot .

.PP

To avoid seeing startup messages from the server use option

.BR -q .

To see all messages from the server use option

.BR -d .

.PP

Some systems will hangup an ftp connection that has no activity

for a given period.  The

.BR -K

option causes ftp to send a NOP command every 15 seconds to attempt

to keep the connection open.  This command can cause some servers to

hangup, so you'll have to feel your way.

.PP

The

.B -t

option causes

.I ftpfs

to negotiate TLS encryption with the server.

.PP

To terminate the connection,

.B unmount

(see

.IR bind (1))

the mount point.

.PP

Since there is no specified format for metadata retrieved

in response to an FTP directory request,

.I ftpfs

has to apply heuristics to steer the interpretation.  Sometimes,

though rarely, these heuristics fail.  The following options are

meant as last resorts to try to steer interpretation.

.PP

A major clue to the heuristics is the operating system at the other

end.  Normally this can be determined automatically using the

FTP SYST command.  However, in some cases the server doesn't implement

the SYST command.  The

.B -o

option will force the case by specifying the name of the operating

system.  Known system types are:

.BR UNIX ,

.BR SUN ,

.BR TOPS ,

.BR Plan9 ,

.BR VM ,

.BR VMS ,

.BR MVS ,

.BR NetWare ,

.BR OS/2 ,

.BR TSO ,

and

.BR WINDOWS_NT .

.PP

Some systems and/or FTP servers return directory listings that don't

include the file extension.  The

.B -e

option allows the user to specify an extension to append to all

remote files (other than directories).

.PP

Finally, there are two FTP commands to retrieve the contents of a

directory, LIST and NLST.  LIST is approximately equivalent to

.L ls -l

and NLST to

.LR ls .

.I Ftpfs

normally uses LIST.  However, some FTP servers interpret LIST

to mean, give a wordy description of the file.

.I Ftpfs

normally notices this and switches to using NLST.  However, in

some rare cases, the user must force the use of NLST with the

.B -n

option.

.SH EXAMPLE

You want anonymous FTP access to the system

.BR export.lcs.mit.edu .

The first

.IR import (4)

command is only necessary if your machine does not have access to the

desired system, but another, called

.B gateway

in this example, does.

.IP

.EX

import gateway /net

ftpfs -a yourname@yourmachine export.lcs.mit.edu

.EE

.SH SOURCE

.B /sys/src/cmd/ip/ftpfs

.SH "SEE ALSO"

.IR bind (2)

.SH BUGS

Symbolic links on remote Unix systems will always have mode 0777

and a length of 8.

.PP

After connecting to a TOPS-20 system, the mount point will contain

only one directory, usually

.BR /n/ftp/PS:<ANONYMOUS> .

However, walking to any valid directory on that machine will succeed

and cause that directory entry to appear under the mount point.

.PP

.I Ftpfs

caches files and directories.  A directory will fall from the cache

after 5 quiescent minutes or if the local user changes the

directory by writing or removing a file.

Otherwise, remote

changes to the directory that occur after the directory has

been cached might not be immediately visible.

Attempting to walk to

.IB directory /.flush.ftpfs

will flush

.I directory

from the cache, thus forcing

.I ftpfs

to re-read it.

.PP

There is no way to issue the appropriate commands to handle special synthetic

FTP file types such as directories

that automatically return a

.B tar

of their contents.

.PP

.I Ftpfs

makes copies in

.B /tmp

of files being transferred,

so its effects might not be immediate.

If there is enough main memory, you might want to run

.IR ramfs (4)

first.

.PP

Filenames containing spaces will confuse

.I ftpfs

(and other FTP clients).