ssh_sftp
SFTP client.
This module implements an SFTP (SSH FTP) client. SFTP is a secure, encrypted file transfer service available for SSH.
DATA TYPES
Type definitions that are used more than once in this module and/or abstractions to indicate the intended use of the data type:
ssh_connection_ref() - opaque to the user
returned by ssh:connect/3
timeout() = infinity | integer() - in milliseconds.
TIMEOUTS
If the request functions for the SFTP channel return {error, timeout} it does not guarantee that the request did not reach the server and was not performed, it only means that we did not receive an answer from the server within the time that was expected.
Functions
start_channel(ConnectionRef) ->
start_channel(ConnectionRef, Options) ->
start_channel(Host, Options) ->
start_channel(Host, Port, Options) -> {ok, Pid} | {ok, Pid, ConnectionRef} | {error, Reason}
Host = string()
ConnectionRef = ssh_connection_ref()
Port = integer()
Options = [{Option, Value}]
Reason = term()
If no connection reference is provided, a connection is set up and the new connection is returned. An SSH channel process is started to handle the communication with the SFTP server. The returned pid for this process should be used as input to all other API functions in this module.
Options are:
{timeout, timeout()}
The timeout is passed to the ssh_channel start function, and defaults to infinity.
All other options are directly passed to ssh:connect/3 or ignored if a connection is already provided.
stop_channel(ChannelPid) -> ok
ChannelPid = pid()
Stops an SFTP channel. Does not close the SSH connetion. Use ssh:close/1 to close it.
read_file(ChannelPid, File) ->
read_file(ChannelPid, File, Timeout) -> {ok, Data} | {error, Reason}
ChannelPid = pid()
File = string()
Data = binary()
Timeout = timeout()
Reason = term()
Reads a file from the server, and returns the data in a binary,
like file:read_file/1
.
write_file(ChannelPid, File, Iolist) ->
write_file(ChannelPid, File, Iolist, Timeout) -> ok | {error, Reason}
ChannelPid = pid()
File = string()
Iolist = iolist()
Timeout = timeout()
Reason = term()
Writes a file to the server, like
file:write_file/2
. The file is created if
it does not exist or is owerwritten if it does.
list_dir(ChannelPid, Path) ->
list_dir(ChannelPid, Path, Timeout) -> {ok, Filenames} | {error, Reason}
ChannelPid = pid()
Path = string()
Filenames = [Filename]
Filename = string()
Timeout = timeout()
Reason = term()
Lists the given directory on the server, returning the filenames as a list of strings.
open(ChannelPid, File, Mode) ->
open(ChannelPid, File, Mode, Timeout) -> {ok, Handle} | {error, Reason}
ChannelPid = pid()
File = string()
Mode = [Modeflag]
Modeflag = read | write | creat | trunc | append | binary
Timeout = timeout()
Handle = term()
Reason = term()
Opens a file on the server, and returns a handle that can be used for reading or writing.
opendir(ChannelPid, Path) ->
opendir(ChannelPid, Path, Timeout) -> {ok, Handle} | {error, Reason}
ChannelPid = pid()
Path = string()
Timeout = timeout()
Reason = term()
Opens a handle to a directory on the server, the handle can be used for reading directory contents.
close(ChannelPid, Handle) ->
close(ChannelPid, Handle, Timeout) -> ok | {error, Reason}
ChannelPid = pid()
Handle = term()
Timeout = timeout()
Reason = term()
Closes a handle to an open file or directory on the server.
read(ChannelPid, Handle, Len) ->
read(ChannelPid, Handle, Len, Timeout) -> {ok, Data} | eof | {error, Error}
pread(ChannelPid, Handle, Position, Len) ->
pread(ChannelPid, Handle, Position, Len, Timeout) -> {ok, Data} | eof | {error, Error}
ChannelPid = pid()
Handle = term()
Position = integer()
Len = integer()
Timeout = timeout()
Data = string() | binary()
Reason = term()
Reads Len
bytes from the file referenced by
Handle
. Returns {ok, Data}
, eof
, or
{error, Reason}
. If the file is opened with binary
,
Data
is a binary, otherwise it is a string.
If the file is read past eof, only the remaining bytes
will be read and returned. If no bytes are read, eof
is returned.
The pread
function reads from a specified position,
combining the position
and read
functions.
aread(ChannelPid, Handle, Len) -> {async, N} | {error, Error}
apread(ChannelPid, Handle, Position, Len) -> {async, N} | {error, Error}
ChannelPid = pid()
Handle = term()
Position = integer()
Len = integer()
N = term()
Reason = term()
Reads from an open file, without waiting for the result. If the
handle is valid, the function returns {async, N}
, where N
is a term guaranteed to be unique between calls of aread
.
The actual data is sent as a message to the calling process. This
message has the form {async_reply, N, Result}
, where
Result
is the result from the read, either {ok, Data}
,
or eof
, or {error, Error}
.
The apread
function reads from a specified position,
combining the position
and aread
functions.
write(ChannelPid, Handle, Data) ->
write(ChannelPid, Handle, Data, Timeout) -> ok | {error, Error}
pwrite(ChannelPid, Handle, Position, Data) -> ok
pwrite(ChannelPid, Handle, Position, Data, Timeout) -> ok | {error, Error}
ChannelPid = pid()
Handle = term()
Position = integer()
Data = iolist()
Timeout = timeout()
Reason = term()
Writesdata
to the file referenced by Handle
.
The file should be opened with write
or append
flag. Returns ok
if successful or S{error, Reason}
otherwise.
Typical error reasons are:
ebadf
The file is not opened for writing.
enospc
There is a no space left on the device.
awrite(ChannelPid, Handle, Data) -> ok | {error, Reason}
apwrite(ChannelPid, Handle, Position, Data) -> ok | {error, Reason}
ChannelPid = pid()
Handle = term()
Position = integer()
Len = integer()
Data = binary()
Timeout = timeout()
Reason = term()
Writes to an open file, without waiting for the result. If the
handle is valid, the function returns {async, N}
, where N
is a term guaranteed to be unique between calls of
awrite
. The result of the write
operation is sent
as a message to the calling process. This message has the form
{async_reply, N, Result}
, where Result
is the result
from the write, either ok
, or {error, Error}
.
The apwrite
writes on a specified position, combining
the position
and awrite
operations.
position(ChannelPid, Handle, Location) ->
position(ChannelPid, Handle, Location, Timeout) -> {ok, NewPosition | {error, Error}
ChannelPid = pid()
Handle = term()
Location = Offset | {bof, Offset} | {cur, Offset} | {eof, Offset} | bof | cur | eof
Offset = integer()
Timeout = timeout()
NewPosition = integer()
Reason = term()
Sets the file position of the file referenced by Handle
.
Returns {ok, NewPosition}
(as an absolute offset) if
successful, otherwise {error, Reason}
. Location
is
one of the following:
Offset
The same as {bof, Offset}
.
{bof, Offset}
Absolute offset.
{cur, Offset}
Offset from the current position.
{eof, Offset}
Offset from the end of file.
bof | cur | eof
The same as above with Offset
0.
read_file_info(ChannelPid, Name) ->
read_file_info(ChannelPid, Name, Timeout) -> {ok, FileInfo} | {error, Reason}
ChannelPid = pid()
Name = string()
Handle = term()
Timeout = timeout()
FileInfo = record()
Reason = term()
Returns a file_info
record from the file specified by
Name
or Handle
, like file:read_file_info/2
.
read_link_info(ChannelPid, Name) -> {ok, FileInfo} | {error, Reason}
read_link_info(ChannelPid, Name, Timeout) -> {ok, FileInfo} | {error, Reason}
ChannelPid = pid()
Name = string()
Handle = term()
Timeout = timeout()
FileInfo = record()
Reason = term()
Returns a file_info
record from the symbolic
link specified by Name
or Handle
, like
file:read_link_info/2
.
write_file_info(ChannelPid, Name, Info) ->
write_file_info(ChannelPid, Name, Info, Timeout) -> ok | {error, Reason}
ChannelPid = pid()
Name = string()
Info = record()
Timeout = timeout()
Reason = term()
Writes file information from a file_info
record to the
file specified by Name
, like file:write_file_info
.
read_link(ChannelPid, Name) ->
read_link(ChannelPid, Name, Timeout) -> {ok, Target} | {error, Reason}
ChannelPid = pid()
Name = string()
Target = string()
Reason = term()
Reads the link target from the symbolic link specified
by name
, like file:read_link/1
.
make_symlink(ChannelPid, Name, Target) ->
make_symlink(ChannelPid, Name, Target, Timeout) -> ok | {error, Reason}
ChannelPid = pid()
Name = string()
Target = string()
Reason = term()
Creates a symbolic link pointing to Target
with the
name Name
, like file:make_symlink/2
.
rename(ChannelPid, OldName, NewName) ->
rename(ChannelPid, OldName, NewName, Timeout) -> ok | {error, Reason}
ChannelPid = pid()
OldName = string()
NewName = string()
Timeout = timeout()
Reason = term()
Renames a file named OldName
, and gives it the name
NewName
, like file:rename/2
delete(ChannelPid, Name) ->
delete(ChannelPid, Name, Timeout) -> ok | {error, Reason}
ChannelPid = pid()
Name = string()
Timeout = timeout()
Reason = term()
Deletes the file specified by Name
, like
file:delete/1
make_dir(ChannelPid, Name) ->
make_dir(ChannelPid, Name, Timeout) -> ok | {error, Reason}
ChannelPid = pid()
Name = string()
Timeout = timeout()
Reason = term()
Creates a directory specified by Name
. Name
should
be a full path to a new directory. The directory can only be
created in an existing directory.
del_dir(ChannelPid, Name) ->
del_dir(ChannelPid, Name, Timeout) -> ok | {error, Reason}
ChannelPid = pid()
Name = string()
Timeout = timeout()
Reason = term()
Deletes a directory specified by Name
.
Note that the directory must be empty before it can be successfully deleted