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Hi all!
Is there a way of checking overflow, carry, etc on integer arithmetic in C#?
I'm an old assembler programmer and I sometimes would like this funtionality when performing bitwise operations on integer variables.
Also, I would like to see ROL and ROR (rotate left, rotate right). Do these exist in C#?
For performance reasons, implementing a class realizing this is not an option.
Thank you.
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See Arithmetic Exceptions[^]. ROL and ROR are not part of the language, you would need to write your own versions.
hanzibal2 wrote: For performance reasons, implementing a class realizing this is not an option.
If you are worried about performance then you should not be using C#.
Use the best guess
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Quote: ROL and ROR are not part of the language
Although << and >> (as well as <<= and >>=) are equivalent to SHL and SHR if I remember my aseembly language correctly...
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You are, of course, correct. I have only once or twice in 20+ years of C/C++/C# programming felt the need for rotation shift operators. But in my assembler days I probably used them all the time.
Use the best guess
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Thank you for your answer.
There are so many advantages with C# over almost any other language that I just can't live without and since C# is the language I chose for my project, why not write repetitive sections as effective as possible?
You are correct, but you answered a question that I didn't ask 
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hanzibal2 wrote: You are correct, but you answered a question that I didn't ask
Where exactly did I do that?
Use the best guess
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Did you consider the checked[^] keyword?
"It was when I found out I could make mistakes that I knew I was on to something."
-Ornette Coleman
"Philosophy is a study that lets us be unhappy more intelligently."
-Anon.
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Great, that's exactly what I was looking for. Thanks!
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checked is horribly slow. If you're working with the carry as a performance optimization, you're better off calculating it manually. See Hacker's Delight chapter 2.12, Overflow Detection.
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Hello all, got myself a confusing mess here. I am going to provide as much information as possible, just let me know if something doesn't make sense.
On load, I have a file check and backup that is executed. The backup, doesn't work at all (the Move) and the create, only creates for the first item in the cluster. Here is the code.
string instText = comboInst.GetItemText(comboInst.SelectedItem);
string folder = instText.Substring(0, 4);
string path = @"C:\Nightly\Institutions\" + folder + "\\";
string email = folder + "Email.txt";
string sourceFile = @"C:\Nightly\Institutions\" + folder + "\\" + folder + "Email.txt";
string destinationFile = @"C:\Nightly\Institutions\" + folder + @"\Archive\";
foreach (string file in settingsFiles)
{
if (File.Exists(path + email))
{
File.Move(sourceFile, destinationFile);
}
if (!File.Exists(path + email))
{
Directory.CreateDirectory(path);
using (File.Create(path + email)) { }
}
What happens is, the file does NOT get moved if the file exists, and when it creates the file if a file doesn't exist, it only does it for the first item in the list, not each as you would expect a foreach statement to process.
If anyone could offer some insight on the wrongdoings of my ways I would appreciate it. Thanks!
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If you run the code you've shown it will throw exceptions at the points where it is failing - examine those exceptions and you will see some of where you're going wrong.
Other points -
You need to check the archive directory exists and doesn't contain a file with that name before calling Move
I would append the filename to your destinationFile string - not just the path
Your loop is going to keep creating/moving the same file
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Put your code in a try-catch block or step through your code to find the exact location of your error.
Once you fix it, your files should move from one location to the other.
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What is in settingsFiles and why do you have a loop which uses the same file name each time through? There is also a bit of duplication in your paths in the above: sourceFile and path + email both evaluate to the same string.
Use the best guess
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settingsFile is a string of settings files, no way to know how many there will be so that is why it loops. Here is the string.
string[] settingsFiles = Directory.GetFiles(@"C:\Nightly\Institutions\", "settings.ini", SearchOption.AllDirectories);
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Yes, but why are you using it to create a loop when it has nothing to do with the file that you are trying to move?
Use the best guess
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The loop, I think, has everything to do with the file. How else would I know what email files are in each directory?
For each *email.txt file in the directories specified do this
{
If the file exists in the directory, move it
}
{
If the file does NOT exist, create it
}
^ so for each file it sees in the string, it should be doing this.
So if I have this structure:
(Folder) (Email Exists?)
1 Y
2 Y
3 N
4 N
5 Y
the intent is to move the file from folder 1 to folder 1\Archive, then create a new one, same for folder 2, then folder 3 doesn't have one so it just creates it, nothing to backup there. Repeat for 4. then backup the file in folder 5 to folder 5\Archive.
Hope that helps with my logic.
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Yes, but look at the code inside the loop. It changes nothing, but uses the same path and file names every time round, nor does it use the content of the item taken from the list.
Use the best guess
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Richard I really appreciate you pointing me in the right direction, I took another look at my logic and you're right, it didn't make sense. It sounded good in my head, but I drew it out on paper to see what I was actually trying to accomplish and it didn't work. So here's what I did, and I am getting the looping result I am after, and I think I can go from here. Take a look.
same strings as above, plus this, different for each
foreach (string file in settingsFiles)
{
IniFile ini = new IniFile(file);
string settingNum = ini.IniReadValue("info", "settingNumber");
if (file.Contains(settingNum))
{
MessageBox.Show("This is setting number: " + settingNum);
continue;
}
}
I have a file call setting.ini and in each I have the category [info] and a generic setting called settingNumber. NOW on form load it does a message box that says "This is setting number: 1, then 2, then 3, then 4. Now to just play with it to do a check to see if the email file exists, if it does, move it, then it will create an email file for each direcotory that contains a settings file. Thanks! This is the best way to learn, being pointed in the right direction, by someone who isn't an a**hole haha. I haven't really had any experiences myself, but sometimes when I use my good friend google, you see some of the responses people give and they are just straight up buttheads. Thanks again :P
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and the finished product! It needs some cleaning up, but for functionalities sake, I am happy with it. Thanks again.
foreach (string file in settingsFiles)
{
IniFile ini = new IniFile(file);
string settingNum = ini.IniReadValue("info", "settingNumber");
if (file.Contains(settingNum))
{
if (File.Exists(@"C:\Nightly\Institutions\" + settingNum + "\\" + settingNum + email))
{
MessageBox.Show("The file Exists for: " + settingNum);
File.Move(@"C:\Nightly\Institutions\" + settingNum + "\\" + settingNum + email, @"C:\Nightly\Institutions\" + settingNum + "\\Archive\\" + Parameters.DateOrTime.fileDate.ToString(Parameters.DateOrTime.formatFileDate) + " - " + settingNum + email);
}
using (File.Create(@"C:\Nightly\Institutions\" + settingNum + "\\" + settingNum + email)) { }
}
}
so a little background on what this does - it checks to see if a file already exists, if it does it will move it to the archive folder in the directory the file is located, and renames it to today's date - email.txt. Then it recreates a blank email to be written to in the future.
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Makes a lot more sense. 
Use the best guess
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string[] files = GetFileList();
foreach (string file in files)
{
Download(file);
}
public string[] GetFileList()
{
string[] downloadFiles;
StringBuilder result = new StringBuilder();
WebResponse response = null;
StreamReader reader = null;
try
{
FtpWebRequest reqFTP;
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/"));
reqFTP.UseBinary = true;
reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
reqFTP.Method = WebRequestMethods.Ftp.ListDirectory;
reqFTP.Proxy = null;
reqFTP.KeepAlive = false;
reqFTP.UsePassive = false;
response = reqFTP.GetResponse();
reader = new StreamReader(response.GetResponseStream());
string line = reader.ReadLine();
while (line != null)
{
result.Append(line);
result.Append("\n");
line = reader.ReadLine();
}
// to remove the trailing '\n'
result.Remove(result.ToString().LastIndexOf('\n'), 1);
return result.ToString().Split('\n');
}
catch (Exception ex)
{
if (reader != null)
{
reader.Close();
}
if (response != null)
{
response.Close();
}
downloadFiles = null;
return downloadFiles;
}
}
private void Download(string file)
{
try
{
string uri = "ftp://" + ftpServerIP + "/" + remoteDir + "/" + file;
Uri serverUri = new Uri(uri);
if (serverUri.Scheme != Uri.UriSchemeFtp)
{
return;
}
FtpWebRequest reqFTP;
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/" + remoteDir + "/" + file));
reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
reqFTP.KeepAlive = false;
reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;
reqFTP.UseBinary = true;
reqFTP.Proxy = null;
reqFTP.UsePassive = false;
FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
Stream responseStream = response.GetResponseStream();
FileStream writeStream = new FileStream(localDestnDir + "\" + file, FileMode.Create);
int Length = 2048;
Byte[] buffer = new Byte[Length];
int bytesRead = responseStream.Read(buffer, 0, Length);
while (bytesRead > 0)
{
writeStream.Write(buffer, 0, bytesRead);
bytesRead = responseStream.Read(buffer, 0, Length);
}
writeStream.Close();
response.Close();
}
catch (WebException wEx)
{
MessageBox.Show(wEx.Message, "Download Error");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "Download Error");
}
}
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Have a look at my article Application Auto-update via Online Files in C#[^] where I implement a progress bar showing the progress of a file download.
“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
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can any one tell is jabber. i want to develop a chat client but i do not want to develop any server end but i want that my clients can talk to other client in same group. outer client will not be expose.
i want to develop chat client which can transfer multiple from one end to other end and also will be capable to transfer image data in form of stream. i hard the jabber client is capable of doing chat and there are already many jabber server so i do not need to maintain my own.
so guide me how i can develop chat client with jabber as a result two user can communicate each other and transfer file and send stream of data from one end to another end. thanks
tbhattacharjee
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Tridip Bhattacharjee wrote: can any one tell is jabber
I can't but this guy[^] can.
Cheers,
Peter
Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012
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