<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
    <title>Target Communication Framework Services - File System</title>
</head>

<body lang='EN-US'>

<h1>Target Communication Framework Services - File System</h1>

<ul>
    <li><a href='#VersionHistory'>Version History</a>
    <li><a href='#Overview'>Overview</a>
    <li><a href='#ReqSync'>Request Synchronization and Reordering</a>
    <li><a href='#FileNames'>File Names</a>
    <li><a href='#FileModes'>File Open Modes</a>
    <li><a href='#FileAttributes'>File Attributes</a>
    <li><a href='#ErrorCodes'>Error Codes</a>
    <li><a href='#Cmds'>Commands</a>
    <ul>
        <li><a href='#CmdOpen'>open</a>
        <li><a href='#CmdClose'>close</a>
        <li><a href='#CmdRead'>read</a>
        <li><a href='#CmdWrite'>write</a>
        <li><a href='#CmdStat'>stat</a>
        <li><a href='#CmdLStat'>lstat</a>
        <li><a href='#CmdFStat'>fstat</a>
        <li><a href='#CmdSetStat'>setstat</a>
        <li><a href='#CmdFSetStat'>fsetstat</a>
        <li><a href='#CmdOpenDir'>opendir</a>
        <li><a href='#CmdReadDir'>readdir</a>
        <li><a href='#CmdMkDir'>mkdir</a>
        <li><a href='#CmdRmDir'>rmdir</a>
        <li><a href='#CmdRoots'>roots</a>
        <li><a href='#CmdRemove'>remove</a>
        <li><a href='#CmdRealPath'>realpath</a>
        <li><a href='#CmdRename'>rename</a>
        <li><a href='#CmdReadLink'>readlink</a>
        <li><a href='#CmdSymLink'>symlink</a>
        <li><a href='#CmdSymLink'>copy</a>
        <li><a href='#CmdSymLink'>user</a>
    </ul>
    <li><a href='#API'>API</a>
</ul>

<h1>File System Service</h1>

<h2><a name='VersionHistory'>Version History</a></h2>

<table border=1 cellpadding=8>
    <tr>
        <th>Version
        <th>Date
        <th>Change
    <tr>
        <td>0.1
        <td>2008-01-10
        <td>Initial contribution
</table>

<h2><a name='Overview'>Overview</a></h2>

<p>File System service provides file transfer (and more generally file
system access) functionality in TCF. The service design is
derived from SSH File Transfer Protocol specifications.</p>

<h2><a name='ReqSync'>Request Synchronization and Reordering</a></h2>

<p>The protocol and implementations MUST process requests relating to
the same file in the order in which they are received.  In other
words, if an application submits multiple requests to the server, the
results in the responses will be the same as if it had sent the
requests one at a time and waited for the response in each case.  For
example, the server may process non-overlapping read/write requests
to the same file in parallel, but overlapping reads and writes cannot
be reordered or parallelized.  However, there are no ordering
restrictions on the server for processing requests from two different
file transfer connections.  The server may interleave and parallelize
them at will.</p>

<p>There are no restrictions on the order in which responses to
outstanding requests are delivered to the client, except that the
server must ensure fairness in the sense that processing of no
request will be indefinitely delayed even if the client is sending
other requests so that there are multiple outstanding requests all
the time.</p>

<p>There is no limit on the number of outstanding (non-acknowledged)
requests that the client may send to the server.  In practice this is
limited by the buffering available on the data stream and the queuing
performed by the server.  If the server's queues are full, it should
not read any more data from the stream, and flow control will prevent
the client from sending more requests.</p>

<h2><a name='FileNames'>File Names</a></h2>

<p>This protocol represents file names as strings.  File names are
assumed to use the slash ('/') character as a directory separator.</p>

<p>File names starting with a slash are "absolute", and are relative to
the root of the file system.  Names starting with any other character
are relative to the user's default directory (home directory). Client
can use 'user()' command to retrieve current user home directory.</p>

<p>Servers SHOULD interpret a path name component ".." as referring to
the parent directory, and "." as referring to the current directory.
If the server implementation limits access to certain parts of the
file system, it must be extra careful in parsing file names when
enforcing such restrictions.  There have been numerous reported
security bugs where a ".." in a path name has allowed access outside
the intended area.</p>

<p>An empty path name is valid, and it refers to the user's default
directory (usually the user's home directory).</p>

<p>Otherwise, no syntax is defined for file names by this specification.
Clients should not make any other assumptions; however, they can
splice path name components returned by readdir() together
using a slash ('/') as the separator, and that will work as expected.</p>

<h2><a name='FileModes'>File Open Modes</a></h2>

<p>File open mode is bitwise OR of mode flags:</p>

<dl>
    <dt><code>TCF_O_READ = 0x00000001</code>
    <dd>Open the file for reading.

    <dt><code>TCF_O_WRITE = 0x00000002</code>
    <dd>Open the file for writing. If both this and TCF_O_READ are
    specified, the file is opened for both reading and writing.

    <dt><code>TCF_O_APPEND = 0x00000004</code>
    <dd>Force all writes to append data at the end of the file.

    <dt><code>TCF_O_CREAT = 0x00000008</code>
    <dd>If this flag is specified, then a new file will be created if one
    does not already exist (if TCF_O_TRUNC is specified, the new file will
    be truncated to zero length if it previously exists).

    <dt><code>TCF_O_TRUNC = 0x00000010</code>
    <dd>Forces an existing file with the same name to be truncated to zero
    length when creating a file by specifying TCF_O_CREAT.
    TCF_O_CREAT MUST also be specified if this flag is used.

    <dt><code>TCF_O_EXCL = 0x00000020</code>
    <dd>Causes the request to fail if the named file already exists.
    TCF_O_CREAT MUST also be specified if this flag is used.
</dl>

<h2><a name='FileAttributes'>File Attributes</a></h2>

<pre><b><font face="Courier New" size=2 color=#333399>
<i>&lt;file attributes&gt;</i>
    &rArr; <i>&lt;object&gt;</i>
</font></b></pre>

<p>All attributes are optional.
Tools and targets can define additional attributes. Predefined attributes are:</p>
<ul>
    <li><code><b><font face="Courier New" size=2 color=#333399>"Size" : <i>&lt;int&gt;</i></font></b></code>
    - file size in bytes
    <li><code><b><font face="Courier New" size=2 color=#333399>"UID" : <i>&lt;int&gt;</i></font></b></code>
    - file owner user ID
    <li><code><b><font face="Courier New" size=2 color=#333399>"GID" : <i>&lt;int&gt;</i></font></b></code>
    - file owner group ID
    <li><code><b><font face="Courier New" size=2 color=#333399>"Permissions" : <i>&lt;int&gt;</i></font></b></code>
    - file access permissions
    <li><code><b><font face="Courier New" size=2 color=#333399>"ATime" : <i>&lt;int&gt;</i></font></b></code>
    - file last access time
    <li><code><b><font face="Courier New" size=2 color=#333399>"MTime" : <i>&lt;int&gt;</i></font></b></code>
    - file last modification time
</ul>

<h2><a name='ErrorCodes'>Error codes</a></h2>

<p>The service uses standard format for error reports,
see <a href='TCF Services.html#ErrorFormat'>Error Report Format</a>.</p>

<p>Currently, the following values are defined for service specific error codes (other values may be
defined by future versions of this protocol):</p>

<dl>
    <dt><code>STATUS_EOF = 0x10001</code>
    <dd>Indicates end-of-file condition; for 'read' it means that no
    more data is available in the file, and for 'readdir' it
    indicates that no more files are contained in the directory.

    <dt><code>STATUS_NO_SUCH_FILE = 0x10002</code>
    <dd>This code is returned when a reference is made to a file which
    should exist but doesn't.

    <dt><code>STATUS_PERMISSION_DENIED = 0x10003</code>
    <dd>is returned when the authenticated user does not have sufficient
    permissions to perform the operation.
</dl>

<h2><a name='Cmds'>Commands</a></h2>

<h3><a name='CmdOpen'>open</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; open &bull; <i>&lt;string: file name&gt;</i> &bull; <i>&lt;int: mode&gt;</i> &bull; <i>&lt;file attributes&gt;</i> &bull;
</font></b></pre>

<p>The command opens or creates a file on a remote system. If mode contains TCF_O_CREAT then new file is created, otherwise exsting
file is opened. If the file is created, file attributes is looked up for UID, GID and permissions. If no attribute value is found in
the command parameters, a default value is used.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull; <i>&lt;file handle&gt;</i> &bull;

<i>&lt;file handle&gt;</i>
    &rArr; null
    &rArr; <i>&lt;string&gt;</i>
</font></b></pre>

<p>On success, the replay contains open file handle. The handle is encoded as a string of characters. Client should never try
to decode the string, but should use it as is to issue further file access commands. Client should close the file when it is
not needed any more. Server should close all files that were left open after client connection was closed ot terminated.</p>

<h3><a name='CmdClose'>close</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; close &bull; <i>&lt;string: file handle&gt;</i> &bull;
</font></b></pre>

<p>The command closes a handle, which was open by 'open' or 'opendir' commands.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdRead'>read</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; read &bull; <i>&lt;string: file handle&gt;</i> &bull; <i>&lt;int: offset&gt;</i> &bull; <i>&lt;int: size&gt;</i> &bull;
</font></b></pre>

<p>The command reads bytes from an open file.
In response to this request, the server will read as many bytes as it
can from the file (up to `size'), and return them in a byte array.
If an error occurs or EOF is encountered, the server may return
fewer bytes then requested. Replay argument 'error report'
will be not null in case of error, and argument 'eof' will be
true in case of EOF. For normal disk files, it is guaranteed
that this will read the specified number of bytes, or up to end of file
or error. For e.g. device files this may return fewer bytes than requested.</p>

<p>If 'offset' < 0 then reading will start from current position in the file.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;string: data&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull; <i>&lt;boolean: eof&gt;</i> &bull;
</font></b></pre>

<p><i>&lt;string: data&gt;</i> is Base64 encoded byte array of file data. Number of bytes is determined by the string length.
'eof' is true when 'data' contains all available bytes up to the end of the file.</p>

<h3><a name='CmdWrite'>write</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; write &bull; <i>&lt;string: file handle&gt;</i> &bull; <i>&lt;int: offset&gt;</i> &bull; <i>&lt;string: data&gt;</i> &bull;
</font></b></pre>

<p>The command writes bytes into an open file.
The write will extend the file if writing beyond the end of the file.
It is legal to write way beyond the end of the file; the semantics
are to write zeroes from the end of the file to the specified offset
and then the data. <i>&lt;string: data&gt;</i> is Base64 encoded array of data bytes.</p>

<p>If 'offset' < 0 then writing will start from current position in the file.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdStat'>stat</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; stat &bull; <i>&lt;string: file name&gt;</i> &bull;
</font></b></pre>

<p>The command retrieves file attributes.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull; <i>&lt;file attributes&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdLStat'>lstat</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; lstat &bull; <i>&lt;string: file name&gt;</i> &bull;
</font></b></pre>

<p>The command retrieves file attributes.
Unlike 'stat', 'lstat' does not follow symbolic links.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull; <i>&lt;file attributes&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdFStat'>fstat</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; fstat &bull; <i>&lt;string: file handle&gt;</i> &bull;
</font></b></pre>

<p>The command retrieves file attributes for an open file (identified by the file handle).</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull; <i>&lt;file attributes&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdSetStat'>setstat</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; setstat &bull; <i>&lt;string: file name&gt;</i> &bull; <i>&lt;file attributes&gt;</i> &bull;
</font></b></pre>

<p>The command sets file attributes.
This request is used for operations such as changing the ownership,
permissions or access times, as well as for truncating a file.
An error will be returned if the specified file system object does
not exist or the user does not have sufficient rights to modify the
specified attributes.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdFSetStat'>fsetstat</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; fsetstat &bull; <i>&lt;string: file handle&gt;</i> &bull; <i>&lt;file attributes&gt;</i> &bull;
</font></b></pre>

<p>The command sets file attributes for an open file (identified by the file handle).
This request is used for operations such as changing the ownership,
permissions or access times, as well as for truncating a file.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdOpenDir'>opendir</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; opendir &bull; <i>&lt;string: path&gt;</i> &bull;
</font></b></pre>

<p>The command opens a directory for reading.
Once the directory has been successfully opened, files (and
directories) contained in it can be listed using 'readdir' requests.
When the client no longer wishes to read more names from the
directory, it SHOULD call 'close' for the handle.  The handle
should be closed regardless of whether a read errors have occurred or not.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull; <i>&lt;file handle&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdReadDir'>readdir</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; readdir &bull; <i>&lt;string: file handle&gt;</i> &bull;
</font></b></pre>

<p>The command returns one
or more file names with full file attributes for each file.  The
client should call 'readdir' repeatedly until it has found the
file it is looking for or until the server responds with a
message indicating an error or end of file. The client should then
close the handle using the 'close' request.
Note: directory entries "." and ".." are NOT included into readdir()
response.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;array of directory entries&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull; <i>&lt;boolean: eof&gt;</i> &bull;

<i>&lt;array of directory entries&gt;</i>
    &rArr; null
    &rArr; [ ]
    &rArr; [ <i>&lt;directory entry list&gt;</i> ]

<i>&lt;directory entry list&gt;</i>
    &rArr; <i>&lt;directory entry&gt;</i>
    &rArr; <i>&ltdirectory entry list&gt;</i> , <i>&lt;directory entry&gt;</i>

<i>&lt;directory entry&gt;</i>
    &rArr; <i>&lt;object&gt;</i>
</font></b></pre>

<p>Directory entry attributes are:</p>
<ul>
    <li><code><b><font face="Courier New" size=2 color=#333399>"FileName" : <i>&lt;string&gt;</i></font></b></code>
    - a file name being returned, it will be a relative name within the directory,
    without any path components.
    <li><code><b><font face="Courier New" size=2 color=#333399>"LongName" : <i>&lt;string&gt;</i></font></b></code>
    - a human readable, expanded format for the file name, similar to what
    is returned by "ls -l" on Unix systems
    <li><code><b><font face="Courier New" size=2 color=#333399>"Attrs" : <i>&lt;file attributes&gt;</i></font></b></code>
    - the attributes of the file as described in Section <a href='#FileAttributes'>File Attributes</a>.
</ul>

<h3><a name='CmdMkDir'>mkdir</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; mkdir &bull; <i>&lt;string: directory path&gt;</i> &bull; <i>&lt;file attributes&gt;</i> &bull;
</font></b></pre>

<p>The command creates a directory on the server.
<i>&lt;string: directory path&gt;</i> specifies the directory to be created.
<i>&lt;file attributes&gt;</i> specifies new directory attributes.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdRmDir'>rmdir</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; rmdir &bull; <i>&lt;string: directory path&gt;</i> &bull;
</font></b></pre>

<p>The command removes a directory.
An error will be returned if no directory
with the specified path exists, or if the specified directory is not
empty, or if the path specified a file system object other than a
directory. <i>&lt;string: directory path&gt;</i> - specifies the directory to be removed.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdRoots'>roots</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; roots &bull;
</font></b></pre>

<p>The command retrieves file system roots - top level file system objects.
UNIX file system can report just one root with path "/". Other types of systems
can have more the one root. For example, Windows server can return multiple roots:
one per disc (e.g. "/C:/", "/D:/", etc.). Note: even Windows implementation of
the service must use forward slash as directory separator, and must start
absolute path with "/". Server should implement proper translation of
protocol file names to OS native names and back.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;array of directory entries&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdRemove'>remove</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; remove &bull; <i>&lt;string: path&gt;</i> &bull;
</font></b></pre>

<p>The command removes a file or symbolic link.
This request cannot be used to remove directories.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdRealPath'>realpath</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; realpath &bull; <i>&lt;string: path&gt;</i> &bull;
</font></b></pre>

<p>The command canonicalizes any given path name to an absolute path.
This is useful for converting path names containing ".." components or
relative pathnames without a leading slash into absolute paths.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull; <i>&lt;string: path&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdRename'>rename</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; rename &bull; <i>&lt;string: old path&gt;</i> &bull; <i>&lt;string: new path&gt;</i> &bull;
</font></b></pre>

<p>The command renames a file.
It is an error if there already exists a file
with the name specified by <i>&lt;string: new path&gt;</i>.  The server may also fail rename
requests in other situations, for example if <i>&lt;string: old path&gt;</i> and <i>&lt;string: new path&gt;</i>
point to different file systems on the server.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdReadLink'>readlink</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; readlink &bull; <i>&lt;string: link path&gt;</i> &bull;
</font></b></pre>

<p>The command reads the target of a symbolic link.
<i>&lt;string: link path&gt;</i> specifies the path name of the symbolic link to be read.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull; <i>&lt;string: path&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdSymLink'>symlink</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; symlink &bull; <i>&lt;string: link path&gt;</i> &bull; <i>&lt;string: target path&gt;</i> &bull;
</font></b></pre>

<p>The command creates a symbolic link on the server.
<i>&lt;string: link path&gt;</i> specifies the path name of the symbolic link to be created.
<i>&lt;string: target path&gt;</i> specifies the target of the symbolic link.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdCopy'>copy</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; copy &bull; <i>&lt;string: source path&gt;</i> &bull; <i>&lt;string: destination path&gt;</i> &bull;
    <i>&lt;boolean: copy permissions&gt;</i> &bull; <i>&lt;boolean: copy ownership&gt;</i> &bull;
</font></b></pre>

<p>The command copies a file on remote system.
<i>&lt;string: source path&gt;</i> specifies the path name of the file to be copied.
<i>&lt;string: destination path&gt;</i> specifies destination file name.
If <i>&lt;boolean: copy permissions&gt;</i> is true then copy source file permissions.
If <i>&lt;boolean: copy ownership&gt;</i> is true then copy source file UID and GID.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;error report&gt;</i> &bull;
</font></b></pre>

<h3><a name='CmdUser'>user</a></h3>

<pre><b><font face="Courier New" size=2 color=#333399>
C &bull; <i>&lt;token&gt;</i> &bull; FileSystem &bull; user &bull;
</font></b></pre>

<p>The command retrieves information about user account, which is used by server
to access file system on behalf of the client.</p>

<p>Reply:</p>

<pre><b><font face="Courier New" size=2 color=#333399>
R &bull; <i>&lt;token&gt;</i> &bull; <i>&lt;int: real UID&gt;</i> &bull; <i>&lt;int: effective UID&gt;</i> &bull;
    <i>&lt;int: real GID&gt;</i> &bull; <i>&lt;int: effective GID&gt;</i> &bull; <i>&lt;string: home directory&gt;</i> &bull;
</font></b></pre>

<h2><a name='API'>API</a></h2>

<pre>
<font color=#3F5FBF>/**
 * File System service provides file transfer (and more generally file
 * system access) functionality in TCF. The service design is
 * derived from SSH File Transfer Protocol specifications.
 */</font>
<font color=#7F0055>public interface</font> IFileSystem <font color=#7F0055>extends</font> IService {

    <font color=#3F5FBF>/**
     * Service name.
     */</font>
    <font color=#7F0055>static final</font> String NAME = "FileSystem";

    <font color=#3F5FBF>/**
     * Flags to be used with open() method.
     */</font>
    <font color=#7F0055>static final int</font>

        <font color=#3F5FBF>/**
         * Open the file for reading.
         */</font>
        TCF_O_READ              = 0x00000001,

        <font color=#3F5FBF>/**
         * Open the file for writing. If both this and TCF_O_READ are
         * specified, the file is opened for both reading and writing.
         */</font>
        TCF_O_WRITE             = 0x00000002,

        <font color=#3F5FBF>/**
         * Force all writes to append data at the end of the file.
         */</font>
        TCF_O_APPEND            = 0x00000004,

        <font color=#3F5FBF>/**
         * If this flag is specified, then a new file will be created if one
         * does not already exist (if TCF_O_TRUNC is specified, the new file will
         * be truncated to zero length if it previously exists).
         */</font>
        TCF_O_CREAT             = 0x00000008,

        <font color=#3F5FBF>/**
         * Forces an existing file with the same name to be truncated to zero
         * length when creating a file by specifying TCF_O_CREAT.
         * TCF_O_CREAT MUST also be specified if this flag is used.
         */</font>
        TCF_O_TRUNC             = 0x00000010,

        <font color=#3F5FBF>/**
         * Causes the request to fail if the named file already exists.
         * TCF_O_CREAT MUST also be specified if this flag is used.
         */</font>
        TCF_O_EXCL              = 0x00000020;

    <font color=#3F5FBF>/**
     * Flags to be used together with FileAttrs.
     * The flags specify which of the fields are present.  Those fields
     * for which the corresponding flag is not set are not present (not
     * included in the message).
     */</font>
    <font color=#7F0055>static final int</font>
        ATTR_SIZE               = 0x00000001,
        ATTR_UIDGID             = 0x00000002,
        ATTR_PERMISSIONS        = 0x00000004,
        ATTR_ACMODTIME          = 0x00000008;

    <font color=#3F5FBF>/**
     * FileAttrs is used both when returning file attributes from
     * the server and when sending file attributes to the server.  When
     * sending it to the server, the flags field specifies which attributes
     * are included, and the server will use default values for the
     * remaining attributes (or will not modify the values of remaining
     * attributes).  When receiving attributes from the server, the flags
     * specify which attributes are included in the returned data.  The
     * server normally returns all attributes it knows about.
     */</font>
    <font color=#7F0055>final static class</font> FileAttrs {

        <font color=#3F5FBF>/**
         * The `flags' specify which of the fields are present.
         */</font>
        <font color=#7F0055>public final int</font> flags;

        <font color=#3F5FBF>/**
         * The `size' field specifies the size of the file in bytes.
         */</font>
        <font color=#7F0055>public final long</font> size;

        <font color=#3F5FBF>/**
         * The `uid' and `gid' fields contain numeric Unix-like user and group
         * identifiers, respectively.
         */</font>
        <font color=#7F0055>public final int</font> uid;
        <font color=#7F0055>public final int</font> gid;

        <font color=#3F5FBF>/**
         * The `permissions' field contains a bit mask of file permissions as
         * defined by posix [1].
         */</font>
        <font color=#7F0055>public final int</font> permissions;

        <font color=#3F5FBF>/**
         * The `atime' and `mtime' contain the access and modification times of
         * the files, respectively. They are represented as milliseconds from
         * midnight Jan 1, 1970 in UTC.
         */</font>
        <font color=#7F0055>public final long</font> atime;
        <font color=#7F0055>public final long</font> mtime;

        <font color=#3F5FBF>/**
         * Additional (non-standard) attributes.
         */</font>
        <font color=#7F0055>public final</font> Map&lt;String,Object&gt; attributes;

        <font color=#7F0055>public</font> FileAttrs(<font color=#7F0055>int</font> flags, <font color=#7F0055>long</font> size, <font color=#7F0055>int</font> uid, <font color=#7F0055>int</font> gid,
                <font color=#7F0055>int</font> permissions, <font color=#7F0055>long</font> atime, <font color=#7F0055>long</font> mtime, Map&lt;String,Object&gt; attributes);

        <font color=#3F5FBF>/**
         * Determines if the file system object is a file on the remote file system.
         *
         * @return true if and only if the object on the remote system can be considered to have "contents" that
         * have the potential to be read and written as a byte stream.
         */</font>
        <font color=#7F0055>public boolean</font> isFile();

        <font color=#3F5FBF>/**
         * Determines if the file system object is a directory on the remote file system.
         *
         * @return true if and only if the object on the remote system is a directory.
         * That is, it contains entries that can be interpreted as other files.
         */</font>
        <font color=#7F0055>public boolean</font> isDirectory();
    }

    <font color=#3F5FBF>/**
     * The following flags are defined for the 'permissions' field:
     */</font>
    <font color=#7F0055>static final int</font>
        S_IFMT     = 0170000,   // bitmask for the file type bitfields
        S_IFSOCK   = 0140000,   // socket
        S_IFLNK    = 0120000,   // symbolic link
        S_IFREG    = 0100000,   // regular file
        S_IFBLK    = 0060000,   // block device
        S_IFDIR    = 0040000,   // directory
        S_IFCHR    = 0020000,   // character device
        S_IFIFO    = 0010000,   // fifo
        S_ISUID    = 0004000,   // set UID bit
        S_ISGID    = 0002000,   // set GID bit (see below)
        S_ISVTX    = 0001000,   // sticky bit (see below)
        S_IRWXU    = 00700,     // mask for file owner permissions
        S_IRUSR    = 00400,     // owner has read permission
        S_IWUSR    = 00200,     // owner has write permission
        S_IXUSR    = 00100,     // owner has execute permission
        S_IRWXG    = 00070,     // mask for group permissions
        S_IRGRP    = 00040,     // group has read permission
        S_IWGRP    = 00020,     // group has write permission
        S_IXGRP    = 00010,     // group has execute permission
        S_IRWXO    = 00007,     // mask for permissions for others (not in group)
        S_IROTH    = 00004,     // others have read permission
        S_IWOTH    = 00002,     // others have write permisson
        S_IXOTH    = 00001;     // others have execute permission

    <font color=#7F0055>final static class</font> DirEntry {
        <font color=#3F5FBF>/**
         * `filename' is a file name being returned. It is a relative name within
         * the directory, without any path components;
         */</font>
        <font color=#7F0055>public final</font> String filename;

        <font color=#3F5FBF>/**
         * `longname' is an expanded format for the file name, similar to what
         * is returned by "ls -l" on Unix systems.
         * The format of the `longname' field is unspecified by this protocol.
         * It MUST be suitable for use in the output of a directory listing
         * command (in fact, the recommended operation for a directory listing
         * command is to simply display this data).  However, clients SHOULD NOT
         * attempt to parse the longname field for file attributes; they SHOULD
         * use the attrs field instead.
         */</font>
        <font color=#7F0055>public final</font> String longname;

        <font color=#3F5FBF>/**
         * `attrs' is the attributes of the file.
         */</font>
        <font color=#7F0055>public final</font> FileAttrs attrs;

        <font color=#7F0055>public</font> DirEntry(String filename, String longname, FileAttrs attrs);
    }

    <font color=#3F5FBF>/**
     * Opaque representation of open file handle.
     * Note: open file handle can be used only with service instance that
     * created the handle.
     */</font>
    <font color=#7F0055>interface</font> IFileHandle {
        IFileSystem getService();
    }

    <font color=#3F5FBF>/**
     * Service specific error codes.
     */</font>
    <font color=#7F0055>static final int</font>

        <font color=#3F5FBF>/**
         * Indicates end-of-file condition; for read() it means that no
         * more data is available in the file, and for readdir() it
         * indicates that no more files are contained in the directory.
         */</font>
        STATUS_EOF = 0x10001,

        <font color=#3F5FBF>/**
         * This code is returned when a reference is made to a file which
         * should exist but doesn't.
         */</font>
        STATUS_NO_SUCH_FILE = 0x10002,

        <font color=#3F5FBF>/**
         * is returned when the authenticated user does not have sufficient
         * permissions to perform the operation.
         */</font>
        STATUS_PERMISSION_DENIED = 0x10003;


    <font color=#3F5FBF>/**
     * The class to represent File System error reports.
     */</font>
    <font color=#7F0055>abstract static class</font> FileSystemException extends IOException {

        <font color=#7F0055>protected</font> FileSystemException(String message);

        <font color=#7F0055>protected</font> FileSystemException(Exception x)

        <font color=#3F5FBF>/**
         * Get error code. The code can be standard TCF error code or
         * one of service specific codes, see STATUS_*.
         * @return error code.
         */</font>
        <font color=#7F0055>public abstract int</font> getStatus();
    }

    <font color=#3F5FBF>/**
     * Open or create a file on a remote system.
     *
     * @param file_name specifies the file name.  See 'File Names' for more information.
     * @param flags is a bit mask of TCF_O_* flags.
     * @param attrs specifies the initial attributes for the file.
     *  Default values will be used for those attributes that are not specified.
     * @param done is call back object.
     * @return pending command handle.
     */</font>
    IToken open(String file_name, <font color=#7F0055>int</font> flags, FileAttrs attrs, DoneOpen done);

    <font color=#7F0055>interface</font> DoneOpen {
        <font color=#7F0055>void</font> doneOpen(IToken token, FileSystemException error, IFileHandle handle);
    }

    <font color=#3F5FBF>/**
     * Close a file on a remote system.
     *
     * @param handle is a handle previously returned in the response to
     * open() or opendir().
     * @param done is call back object.
     * @return pending command handle.
     */</font>
    IToken close(IFileHandle handle, DoneClose done);

    <font color=#7F0055>interface</font> DoneClose {
        <font color=#7F0055>void</font> doneClose(IToken token, FileSystemException error);
    }

    <font color=#3F5FBF>/**
     * Read bytes from an open file.
     * In response to this request, the server will read as many bytes as it
     * can from the file (up to `len'), and return them in a byte array.
     * If an error occurs or EOF is encountered, the server may return
     * fewer bytes then requested. Call back method doneRead() argument 'error'
     * will be not null in case of error, and argument 'eof' will be
     * true in case of EOF. For normal disk files, it is guaranteed
     * that this will read the specified number of bytes, or up to end of file
     * or error. For e.g. device files this may return fewer bytes than requested.
     *
     * @param handle is an open file handle returned by open().
     * @param offset is the offset (in bytes) relative
     * to the beginning of the file from where to start reading.
     * @param len is the maximum number of bytes to read.
     * @param done is call back object.
     * @return pending command handle.
     */</font>
    IToken read(IFileHandle handle, long offset, <font color=#7F0055>int</font> len, DoneRead done);

    <font color=#7F0055>interface</font> DoneRead {
        <font color=#7F0055>void</font> doneRead(IToken token, FileSystemException error, byte[] data, boolean eof);
    }

    <font color=#3F5FBF>/**
     * Write bytes into an open file.
     * The write will extend the file if writing beyond the end of the file.
     * It is legal to write way beyond the end of the file; the semantics
     * are to write zeroes from the end of the file to the specified offset
     * and then the data.
     *
     * @param handle is an open file handle returned by open().
     * @param offset is the offset (in bytes) relative
     * to the beginning of the file from where to start writing.
     * @param data is byte array that contains data for writing.
     * @param data_pos if offset in 'data' of first byte to write.
     * @param data_size is the number of bytes to write.
     * @param done is call back object.
     * @return pending command handle.
     */</font>
    IToken write(IFileHandle handle, long offset,
            byte[] data, <font color=#7F0055>int</font> data_pos, <font color=#7F0055>int</font> data_size, DoneWrite done);

    <font color=#7F0055>interface</font> DoneWrite {
        <font color=#7F0055>void</font> doneWrite(IToken token, FileSystemException error);
    }

    <font color=#3F5FBF>/**
     * Retrieve file attributes.
     *
     * @param path - specifies the file system object for which
     * status is to be returned.
     * @param done is call back object.
     * @return pending command handle.
     */</font>
    IToken stat(String path, DoneStat done);

    <font color=#3F5FBF>/**
     * Retrieve file attributes.
     * Unlike 'stat()', 'lstat()' does not follow symbolic links.
     *
     * @param path - specifies the file system object for which
     * status is to be returned.
     * @param done is call back object.
     * @return pending command handle.
     */</font>
    IToken lstat(String path, DoneStat done);

    <font color=#3F5FBF>/**
     * Retrieve file attributes for an open file (identified by the file handle).
     *
     * @param handle is a file handle returned by 'open()'.
     * @param done is call back object.
     * @return pending command handle.
     */</font>
    IToken fstat(IFileHandle handle, DoneStat done);

    <font color=#7F0055>interface</font> DoneStat {
        <font color=#7F0055>void</font> doneStat(IToken token, FileSystemException error, FileAttrs attrs);
    }

    <font color=#3F5FBF>/**
     * Set file attributes.
     * This request is used for operations such as changing the ownership,
     * permissions or access times, as well as for truncating a file.
     * An error will be returned if the specified file system object does
     * not exist or the user does not have sufficient rights to modify the
     * specified attributes.
     *
     * @param path specifies the file system object (e.g. file or directory)
     * whose attributes are to be modified.
     * @param attrs specifies the modifications to be made to file attributes.
     * @param done is call back object.
     * @return pending command handle.
     */</font>
    IToken setstat(String path, FileAttrs attrs, DoneSetStat done);

    <font color=#3F5FBF>/**
     * Set file attributes for an open file (identified by the file handle).
     * This request is used for operations such as changing the ownership,
     * permissions or access times, as well as for truncating a file.
     *
     * @param handle is a file handle returned by 'open()'.
     * @param attrs specifies the modifications to be made to file attributes.
     * @param done is call back object.
     * @return pending command handle.
     */</font>
    IToken fsetstat(IFileHandle handle, FileAttrs attrs, DoneSetStat done);

    <font color=#7F0055>interface</font> DoneSetStat {
        <font color=#7F0055>void</font> doneSetStat(IToken token, FileSystemException error);
    }

    <font color=#3F5FBF>/**
     * The opendir() command opens a directory for reading.
     * Once the directory has been successfully opened, files (and
     * directories) contained in it can be listed using readdir() requests.
     * When the client no longer wishes to read more names from the
     * directory, it SHOULD call close() for the handle.  The handle
     * should be closed regardless of whether an error has occurred or not.

     * @param path - name of the directory to be listed (without any trailing slash).
     * @param done - result call back object.
     * @return pending command handle.
     */</font>
    IToken opendir(String path, DoneOpen done);

    <font color=#3F5FBF>/**
     * The files in a directory can be listed using the opendir() and
     * readdir() requests.  Each readdir() request returns one
     * or more file names with full file attributes for each file.  The
     * client should call readdir() repeatedly until it has found the
     * file it is looking for or until the server responds with a
     * message indicating an error or end of file. The client should then
     * close the handle using the close() request.
     * Note: directory entries "." and ".." are NOT included into readdir()
     * response.
     * @param handle - file handle created by opendir()
     * @param done - result call back object.
     * @return pending command handle.
     */</font>
    IToken readdir(IFileHandle handle, DoneReadDir done);

    <font color=#7F0055>interface</font> DoneReadDir {
        <font color=#7F0055>void</font> doneReadDir(IToken token, FileSystemException error, DirEntry[] entries, boolean eof);
    }

    <font color=#3F5FBF>/**
     * Create a directory on the server.
     *
     * @param path - specifies the directory to be created.
     * @param attrs - new directory attributes.
     * @param done - result call back object.
     * @return pending command handle.
     */</font>
    IToken mkdir(String path, FileAttrs attrs, DoneMkDir done);

    <font color=#7F0055>interface</font> DoneMkDir {
        <font color=#7F0055>void</font> doneMkDir(IToken token, FileSystemException error);
    }

    <font color=#3F5FBF>/**
     * Remove a directory.
     * An error will be returned if no directory
     * with the specified path exists, or if the specified directory is not
     * empty, or if the path specified a file system object other than a
     * directory.
     *
     * @param path - specifies the directory to be removed.
     * @param done - result call back object.
     * @return pending command handle.
     */</font>
    IToken rmdir(String path, DoneRemove done);

    <font color=#7F0055>interface</font> DoneRemove {
        <font color=#7F0055>void</font> doneRemove(IToken token, FileSystemException error);
    }

    <font color=#3F5FBF>/**
     * Retrieve file system roots - top level file system objects.
     * UNIX file system can report just one root with path "/". Other types of systems
     * can have more the one root. For example, Windows server can return multiple roots:
     * one per disc (e.g. "/C:/", "/D:/", etc.). Note: even Windows implementation of
     * the service must use forward slash as directory separator, and must start
     * absolute path with "/". Server should implement proper translation of
     * protocol file names to OS native names and back.
     *
     * @param done - result call back object.
     * @return pending command handle.
     */</font>
    IToken roots(DoneRoots done);

    <font color=#7F0055>interface</font> DoneRoots {
        <font color=#7F0055>void</font> doneRoots(IToken token, FileSystemException error, DirEntry[] entries);
    }

    <font color=#3F5FBF>/**
     * Remove a file or symbolic link.
     * This request cannot be used to remove directories.
     *
     * @param file_name is the name of the file to be removed.
     * @param done - result call back object.
     * @return pending command handle.
     */</font>
    IToken remove(String file_name, DoneRemove done);

    <font color=#3F5FBF>/**
     * Canonicalize any given path name to an absolute path.
     * This is useful for converting path names containing ".." components or
     * relative pathnames without a leading slash into absolute paths.
     *
     * @param path specifies the path name to be canonicalized.
     * @param done - result call back object.
     * @return pending command handle.
     */</font>
    IToken realpath(String path, DoneRealPath done);

    <font color=#7F0055>interface</font> DoneRealPath {
        <font color=#7F0055>void</font> doneRealPath(IToken token, FileSystemException error, String path);
    }

    <font color=#3F5FBF>/**
     * Rename a file.
     * It is an error if there already exists a file
     * with the name specified by 'new_path'.  The server may also fail rename
     * requests in other situations, for example if `old_path' and `new_path'
     * point to different file systems on the server.
     *
     * @param old_path is the name of an existing file or directory.
     * @param new_path is the new name for the file or directory.
     * @param done - result call back object.
     * @return pending command handle.
     */</font>
    IToken rename(String old_path, String new_path, DoneRename done);

    <font color=#7F0055>interface</font> DoneRename {
        <font color=#7F0055>void</font> doneRename(IToken token, FileSystemException error);
    }

    <font color=#3F5FBF>/**
     * Read the target of a symbolic link.
     *
     * @param path specifies the path name of the symbolic link to be read.
     * @param done - result call back object.
     * @return pending command handle.
     */</font>
    IToken readlink(String path, DoneReadLink done);

    <font color=#7F0055>interface</font> DoneReadLink {
        <font color=#7F0055>void</font> doneReadLink(IToken token, FileSystemException error, String path);
    }

    <font color=#3F5FBF>/**
     * Create a symbolic link on the server.
     *
     * @param link_path specifies the path name of the symbolic link to be created.
     * @param target_path specifies the target of the symbolic link.
     * @param done - result call back object.
     * @return pending command handle.
     */</font>
    IToken symlink(String link_path, String target_path, DoneSymLink done);

    <font color=#7F0055>interface</font> DoneSymLink {
        <font color=#7F0055>void</font> doneSymLink(IToken token, FileSystemException error);
    }

    <font color=#3F5FBF>/**
     * Copy a file on remote system.
     *
     * @param src_path specifies the path name of the file to be copied.
     * @param dst_path specifies destination file name.
     * @param copy_permissions - if true then copy source file permissions.
     * @param copy_ownership - if true then copy source file UID and GID.
     * @param done - result call back object.
     * @return pending command handle.
     */</font>
    IToken copy(String src_path, String dst_path,
            boolean copy_permissions, boolean copy_ownership, DoneCopy done);

    <font color=#7F0055>interface</font> DoneCopy {
        <font color=#7F0055>void</font> doneCopy(IToken token, FileSystemException error);
    }

    <font color=#3F5FBF>/**
     * Retrieve information about user account, which is used by server
     * to access file system on behalf of the client.
     *
     * @param done - result call back object.
     * @return pending command handle.
     */</font>
    IToken user(DoneUser done);

    <font color=#7F0055>interface</font> DoneUser {
        <font color=#7F0055>void</font> doneUser(IToken token, FileSystemException error,
                <font color=#7F0055>int</font> real_uid, <font color=#7F0055>int</font> effective_uid, <font color=#7F0055>int</font> real_gid, <font color=#7F0055>int</font> effective_gid,
                String home);
    }
}
</pre>

</body>
</html>