问题
I have an application that does the following: directory listing, download file, download all.
I have an issue with getting the file names from WebRequestMethods.Ftp.ListDirectoryDetails. It seems that it is not possible to do so for every scenario.
WebRequestMethods.Ftp.ListDirectoryDetails returns a lineItem in the following manner:
"-rw-r--r-- 1 ftp ftp 39979 Aug 01 16:02 db to pc 2014-08-05 07-30-00.csv"
I am using the first character to determine if it is a file or directory. Then I split the file on space and get the file name after a fixed index amount within the split. The issue in my implementation is that if a file has multiple spaces then it would be incorrectly referenced with less spaces and the file would not be found when attempting to download it.
I am not able use the split.last() since a file name can have spaces nor WebRequestMethods.Ftp.ListDirectory since it does not allow us to distinguish between a Directory and a file without an extension. Nor a regex since a file name can have a date in it. Any assistance in finding a solution that completely covers all cases would be great.
bool isDirectory = line.Substring(0,1).Equals("d", System.StringComparison.OrdinalIgnoreCase);
string[] itemNames = line.Split(new[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries).Select((value, index) => new { value, index }).Where(i => i.index > 7).Select(i => i.value).ToArray();
string val = string.Join(" ", itemNames);
回答1:
The final solution was to use regex and split it using groups. This resolved all issues and allowed me to get the file / directory name and whether it was a directory or file.
string regex =
@"^" + //# Start of line
@"(?<dir>[\-ld])" + //# File size
@"(?<permission>[\-rwx]{9})" + //# Whitespace \n
@"\s+" + //# Whitespace \n
@"(?<filecode>\d+)" +
@"\s+" + //# Whitespace \n
@"(?<owner>\w+)" +
@"\s+" + //# Whitespace \n
@"(?<group>\w+)" +
@"\s+" + //# Whitespace \n
@"(?<size>\d+)" +
@"\s+" + //# Whitespace \n
@"(?<month>\w{3})" + //# Month (3 letters) \n
@"\s+" + //# Whitespace \n
@"(?<day>\d{1,2})" + //# Day (1 or 2 digits) \n
@"\s+" + //# Whitespace \n
@"(?<timeyear>[\d:]{4,5})" + //# Time or year \n
@"\s+" + //# Whitespace \n
@"(?<filename>(.*))" + //# Filename \n
@"$"; //# End of line
var split = new Regex(regex).Match(line);
string dir = split.Groups["dir"].ToString();
string filename = split.Groups["filename"].ToString();
bool isDirectory = !string.IsNullOrWhiteSpace(dir) && dir.Equals("d", StringComparison.OrdinalIgnoreCase);
Thanks to: http://blogs.msdn.com/b/adarshk/archive/2004/09/15/sample-code-for-parsing-ftpwebrequest-response-for-listdirectorydetails.aspx for providing the regex.
回答2:
Simpler solution could be:
isDirectory=line[0]=='d';
filename = line.Split(new char[] {' '}, 9,StringSplitOptions.RemoveEmptyEntries)[8]
回答3:
Based on Sasa's suggestion, the following code can be used to get a list of files.
List<string> availableFiles = new List<string>();
string line = string.Empty;
ftpRequest.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
using (FtpWebResponse response = (FtpWebResponse)ftpRequest.GetResponse())
{
using (StreamReader streamReader = new StreamReader(response.GetResponseStream()))
{
line = streamReader.ReadLine();
while (!string.IsNullOrEmpty(line))
{
if (line[0] != 'd')
{
availableFiles.Add(line.Split(new char[] { ' ' }, 9, StringSplitOptions.RemoveEmptyEntries)[8]);
}
line = streamReader.ReadLine();
}
}
}
来源:https://stackoverflow.com/questions/25246426/extracting-file-names-from-webrequestmethods-ftp-listdirectorydetails