/// <summary>
/// Gets a file listing from the server asynchronously. Each <see cref="FtpListItem"/> object returned
/// contains information about the file that was able to be retrieved.
/// </summary>
/// <remarks>
/// If a <see cref="DateTime"/> property is equal to <see cref="DateTime.MinValue"/> then it means the
/// date in question was not able to be retrieved. If the <see cref="FtpListItem.Size"/> property
/// is equal to 0, then it means the size of the object could also not
/// be retrieved.
/// </remarks>
/// <param name="path">The path to list</param>
/// <param name="options">Options that dictate how the list operation is performed</param>
/// <param name="token">Cancellation Token</param>
/// <returns>An array of items retrieved in the listing</returns>
public async Task <FtpListItem[]> GetListingAsync(string path, FtpListOption options, CancellationToken token = default(CancellationToken))
{
// start recursive process if needed and unsupported by the server
if ((options & FtpListOption.Recursive) == FtpListOption.Recursive && !RecursiveList)
{
return(await GetListingRecursiveAsync(GetAbsolutePath(path), options));
}
this.LogFunc(nameof(GetListingAsync), new object[] { path, options });
FtpListItem item = null;
List <FtpListItem> lst = new List <FtpListItem>();
List <string> rawlisting = new List <string>();
string listcmd = null;
string buf = null;
// read flags
bool isIncludeSelf = (options & FtpListOption.IncludeSelfAndParent) == FtpListOption.IncludeSelfAndParent;
bool isForceList = (options & FtpListOption.ForceList) == FtpListOption.ForceList;
bool isNoPath = (options & FtpListOption.NoPath) == FtpListOption.NoPath;
bool isNameList = (options & FtpListOption.NameList) == FtpListOption.NameList;
bool isUseLS = (options & FtpListOption.UseLS) == FtpListOption.UseLS;
bool isAllFiles = (options & FtpListOption.AllFiles) == FtpListOption.AllFiles;
bool isRecursive = (options & FtpListOption.Recursive) == FtpListOption.Recursive && RecursiveList;
bool isDerefLinks = (options & FtpListOption.DerefLinks) == FtpListOption.DerefLinks;
bool isGetModified = (options & FtpListOption.Modify) == FtpListOption.Modify;
bool isGetSize = (options & FtpListOption.Size) == FtpListOption.Size;
// calc path to request
path = await GetAbsolutePathAsync(path, token);
// MLSD provides a machine readable format with 100% accurate information
// so always prefer MLSD over LIST unless the caller of this method overrides it with the ForceList option
bool machineList = false;
if ((!isForceList || m_parser == FtpParser.Machine) && HasFeature(FtpCapability.MLSD))
{
listcmd = "MLSD";
machineList = true;
}
else
{
if (isUseLS)
{
listcmd = "LS";
}
else if (isNameList)
{
listcmd = "NLST";
}
else
{
string listopts = "";
listcmd = "LIST";
if (isAllFiles)
{
listopts += "a";
}
if (isRecursive)
{
listopts += "R";
}
if (listopts.Length > 0)
{
listcmd += " -" + listopts;
}
}
}
if (!isNoPath)
{
listcmd = (listcmd + " " + path.GetFtpPath());
}
await ExecuteAsync("TYPE I", token);
// read in raw file listing
try
{
using (FtpDataStream stream = await OpenDataStreamAsync(listcmd, 0, token))
{
try
{
this.LogLine(FtpTraceLevel.Verbose, "+---------------------------------------+");
if (this.BulkListing)
{
// increases performance of GetListing by reading multiple lines of the file listing at once
foreach (var line in await stream.ReadAllLinesAsync(Encoding, this.BulkListingLength, token))
{
if (!FtpExtensions.IsNullOrWhiteSpace(line))
{
rawlisting.Add(line);
this.LogLine(FtpTraceLevel.Verbose, "Listing: " + line);
}
}
}
else
{
// GetListing will read file listings line-by-line (actually byte-by-byte)
while ((buf = await stream.ReadLineAsync(Encoding, token)) != null)
{
if (buf.Length > 0)
{
rawlisting.Add(buf);
this.LogLine(FtpTraceLevel.Verbose, "Listing: " + buf);
}
}
}
this.LogLine(FtpTraceLevel.Verbose, "-----------------------------------------");
}
finally
{
stream.Close();
}
}
}
catch (FtpMissingSocketException)
{
// Some FTP server does not send any response when listing an empty directory
// and the authentication fails, if no communication socket is provided by the server
}
for (int i = 0; i < rawlisting.Count; i++)
{
buf = rawlisting[i];
if (isNameList)
{
// if NLST was used we only have a file name so
// there is nothing to parse.
item = new FtpListItem()
{
FullName = buf
};
if (await DirectoryExistsAsync(item.FullName, token))
{
item.Type = FtpFileSystemObjectType.Directory;
}
else
{
item.Type = FtpFileSystemObjectType.File;
}
lst.Add(item);
}
else
{
// if this is a result of LIST -R then the path will be spit out
// before each block of objects
if (listcmd.StartsWith("LIST") && isRecursive)
{
if (buf.StartsWith("/") && buf.EndsWith(":"))
{
path = buf.TrimEnd(':');
continue;
}
}
// if the next line in the listing starts with spaces
// it is assumed to be a continuation of the current line
if (i + 1 < rawlisting.Count && (rawlisting[i + 1].StartsWith("\t") || rawlisting[i + 1].StartsWith(" ")))
{
buf += rawlisting[++i];
}
try
{
item = m_listParser.ParseSingleLine(path, buf, m_caps, machineList);
}
catch (FtpListParser.CriticalListParseException)
{
this.LogStatus(FtpTraceLevel.Verbose, "Restarting parsing from first entry in list");
i = -1;
lst.Clear();
continue;
}
// FtpListItem.Parse() returns null if the line
// could not be parsed
if (item != null)
{
if (isIncludeSelf || !(item.Name == "." || item.Name == ".."))
{
lst.Add(item);
}
else
{
//this.LogStatus(FtpTraceLevel.Verbose, "Skipped self or parent item: " + item.Name);
}
}
else
{
this.LogStatus(FtpTraceLevel.Warn, "Failed to parse file listing: " + buf);
}
}
// load extended information that wasn't available if the list options flags say to do so.
if (item != null)
{
// try to dereference symbolic links if the appropriate list
// option was passed
if (item.Type == FtpFileSystemObjectType.Link && isDerefLinks)
{
item.LinkObject = await DereferenceLinkAsync(item, token);
}
// if need to get file modified date
if (isGetModified && HasFeature(FtpCapability.MDTM))
{
// if the modified date was not loaded or the modified date is more than a day in the future
// and the server supports the MDTM command, load the modified date.
// most servers do not support retrieving the modified date
// of a directory but we try any way.
if (item.Modified == DateTime.MinValue || listcmd.StartsWith("LIST"))
{
DateTime modify;
if (item.Type == FtpFileSystemObjectType.Directory)
{
this.LogStatus(FtpTraceLevel.Verbose, "Trying to retrieve modification time of a directory, some servers don't like this...");
}
if ((modify = await GetModifiedTimeAsync(item.FullName, token: token)) != DateTime.MinValue)
{
item.Modified = modify;
}
}
}
// if need to get file size
if (isGetSize && HasFeature(FtpCapability.SIZE))
{
// if no size was parsed, the object is a file and the server
// supports the SIZE command, then load the file size
if (item.Size == -1)
{
if (item.Type != FtpFileSystemObjectType.Directory)
{
item.Size = await GetFileSizeAsync(item.FullName, token);
}
else
{
item.Size = 0;
}
}
}
}
}
return(lst.ToArray());
}
/// <summary>
/// Get the records of a file listing and retry if temporary failure.
/// </summary>
private async Task <List <string> > GetListingInternalAsync(string listcmd, bool retry, CancellationToken token)
{
List <string> rawlisting = new List <string>();
// always get the file listing in binary to avoid character translation issues with ASCII.
await SetDataTypeNoLockAsync(FtpDataType.Binary, token);
try {
// read in raw file listing
using (FtpDataStream stream = await OpenDataStreamAsync(listcmd, 0, token)) {
try {
this.LogLine(FtpTraceLevel.Verbose, "+---------------------------------------+");
if (this.BulkListing)
{
// increases performance of GetListing by reading multiple lines of the file listing at once
foreach (var line in await stream.ReadAllLinesAsync(Encoding, this.BulkListingLength, token))
{
if (!FtpExtensions.IsNullOrWhiteSpace(line))
{
rawlisting.Add(line);
this.LogLine(FtpTraceLevel.Verbose, "Listing: " + line);
}
}
}
else
{
// GetListing will read file listings line-by-line (actually byte-by-byte)
string buf;
while ((buf = await stream.ReadLineAsync(Encoding, token)) != null)
{
if (buf.Length > 0)
{
rawlisting.Add(buf);
this.LogLine(FtpTraceLevel.Verbose, "Listing: " + buf);
}
}
}
this.LogLine(FtpTraceLevel.Verbose, "-----------------------------------------");
} finally {
stream.Close();
}
}
} catch (FtpMissingSocketException) {
// Some FTP server does not send any response when listing an empty directory
// and the connection fails because no communication socket is provided by the server
} catch (IOException ioEx) {
// Some FTP servers forcibly close the connection, we absorb these errors
// Fix #410: Retry if its a temporary failure ("Received an unexpected EOF or 0 bytes from the transport stream")
if (retry && ioEx.Message.IsKnownError(unexpectedEOFStrings))
{
// retry once more, but do not go into a infinite recursion loop here
return(await GetListingInternalAsync(listcmd, false, token));
}
else
{
// suppress all other types of exceptions
}
}
return(rawlisting);
}
