I was wondering if there is a more efficient way of modifying the text in the console. For example: if I am keeping track of the number of events that have occurred, I'll print
0 events have occurred
and as events occur I want to increment that 0.
Currently I am doing that in a very ugly way:
Keep track of everything printed to the console using a String or Stringbuilder and if I need to make any changes, change the string, clear the console, print the string to the console. Aside from probably not being very efficient, it displays in an ugly way resulting in the console's "blinking" when too many changes are made in a short period of time.
Thanks in advance.
The trick is to use the carriage return code. This basically returns the cursor to the beginning of the same line. This is different from the carriage return + line feed (vbCrLf), which puts the cursor at the beginning of the next line.
There are slightly different ways to do this in VB vs. C#.
VB: Use the vbCr code.
C#: Use the \r code.
Here's some sample code:
VB:
For i = 1 To 100
Console.Write("Processing...{0}% complete " & vbCr, i)
System.Threading.Thread.Sleep(100)
Next
C#:
for (int i = 1; i <= 100; i++)
{
Console.Write("Processing... {0}% complete\r", i);
System.Threading.Thread.Sleep(100);
}
Related
So.
I am making a bruteforcer in visual basic.
It has a charset as shown below:
Dim charset as string
charset = "abcdefghijklmnopqrstuvwxyz1234567890."
There is 37 different chars right? The program is made to search for all the different combinations made with this charset, with a maximum of 3 different letters. For example
This is a combination that can be made: ac6
So since there is 37 letters and 3 slots the possible combinations are 37^3
But I wanted my program not to try the same combination twice.
So it saves every single combination tried in this location (Desktop)
Dim filex As System.IO.StreamWriter
filex = My.Computer.FileSystem.OpenTextFileWriter("c:\Users\" + Environment.UserName + "\desktop\alreadytested.txt", True)
filex.WriteLine(combination)
filex.Close()
And, at the start of the Sub that checks for new combinations, I have this
text = File.ReadAllText("c:\Users\" + Environment.UserName + "\desktop\alreadytested.txt")
index = text.IndexOf(combination) 'checks if it has been generated already
If index >= 0 Then
keyword() 'The sub
End If
But after some combinations (in this case the max 37^3 ~= 50.000 and I the program tried around 5200 times) I get this error
An unhandled exception of type 'System.StackOverflowException' occurred in mscorlib.dll
And this error points in this line of code
filex = My.Computer.FileSystem.OpenTextFileWriter("c:\Users\" + Environment.UserName + "\desktop\alreadytested.txt", True)
But why? at 5200 there is still 44800 possible random combinations, why do I get an overflow?
It would make sense if I got it when I had 50000 combinations out of 50000 possible tested, but now I have 10% only, so why do I get an overflow?
You keep on recursively calling the keyword() method. Every time you call a method its return address and possibly its arguments is/are added to the call stack. The callstack can only take a certain amount of calls before it overflows, and for your computer and that specific method of yours, that amount seems to be about 5200.
You should switch to using for example a While-loop instead, and whenever you want to block the rest of the execution and go back to the beginning of the loop you'd just call Continue While.
A little side note is also that you shouldn't open and close the file every time you read/write to it. Store the contents of the file in a long string (or even better, in a HashSet(Of T)) instead and check that every time you need to, then at the end of the loop you may write all the contents to a file.
If you still wish to write to the file during the process then do so. But instead open a stream before your loop which you keep writing to until the loop is finished, then close the stream.
I want my program to read a certain part of a huge txt file, change one value and save the file again.
The file that needs editing looks like this:
168575 = {
name="Hidda"
female=yes
dynasty=9601
religion="catholic"
culture="german"
father=168573
960.1.1 = {
birth=yes
}
1030.1.1 = {
death=yes
}
}
My VB program takes the IDs from the blocks it has to change from another textbox like this.
31060
106551
106550
168575
40713
106523
106522
106555
As you can see, the number I want changed is in the middle of the textbox, the code I use to get the number from the line and look for it in the huge file is
Dim strText() As String
strText = Split(chars.Text, vbCrLf)
and later
If line.Contains(strText(0) & " = {") Then
TextBox1.AppendText(line & Environment.NewLine)
To form a code like:
Dim strText() As String
strText = Split(chars.Text, vbCrLf)
Label4.Text = strText(0)
Dim line As String = Nothing
Dim lines2 As Integer = 0
Using reader2 As New StreamReader("c:/dutch.txt")
While (reader2.Peek() <> -1)
line = reader2.ReadLine()
If line.Contains(strText(0) & " = {") Then
TextBox1.AppendText(line & Environment.NewLine)
End If
lines2 = lines2 + 1
Label2.Text = lines2
End While
End Using
Naturally, this only writes in a textbox the line that it found, how do I get the whole code with that IDs I take from 1 textbox, change the culture to another value and save it again? And repeat this for all the IDs in a textbox? Im not a coding legend but this has been bothering me for ages now :(
There are a few issues to consider here. If you're dealing with a large text file as a "database" and you wish to edit only parts of it without affecting the other parts, then you may wish to investigate editing it as a binary file instead of as a text stream. This has several downsides, however, since it means that you have to be aware of how big your records are and deal with things like padding.
If you can spare the disk IO and RAM (I don't know how huge you mean when you say huge) it would probably be vastly easier to simply load the entire file into an array or List(Of String), find the line representing the person, seek a few lines below that for the field you want (you said culture), change that field in the array or List, and then just resave the entire array or List back to a text file. This would make it fairly easy to do inserts and you wouldn't have to worry about padding, mostly you'd just have to worry about the line endings and the file encoding (and the amount of disk IO and RAM).
Finally, I would suggest that using a custom format text file as a database is generally a "bad" idea in 2014 unless you have a really good reason to be doing that. Your format looks very similar to JSON - perhaps you could consider using that instead of your existing format. Then there would be libraries such as JSON.Net to help you do the right thing and you wouldn't need to do any custom IO code.
So I looked through other user's question but couldn't find on specifically upon what I am looking for. What I am trying to do is very simple. I am writing a Visual Studio Macro and am trying to obtain the number of the current line that the TextSelection is on. So that's it really, my question is quite simple. How do you get the number of the line that the selection is currently at? Any help is greatly appreciated!
Just so it's clear to anybody reading this, I am using VB and am writing Visual Studio Macro.
Keep in mind that a TextSelection can span multiple lines, so there's potentially a range of lines.
Looking at the docs for TextSelection (i.e. I haven't tested this), you should be able to do something like this:
Dim mySelection As EnvDTE.TextSelection = ' however you get the active selection
mySelection.TopPoint.Line ' gets the line of the top of the selection
If you want to get it based on where the cursor is (top or bottom of the selection) you can try this:
mySelection.ActivePoint.Line
It looks like the TextRanges might also be useful, but it sounds like it's for box selection only, so it might not apply.
mySelection.TextRanges.Item(0).Line
There is probably a better way than this, but the first way that comes to my mind is something like this.
First, make sure that the last line in your file is "xyz"
Dim linenumber As Integer = 1
dim mystring as string = ""
Using myfile As New IO.StreamReader("C:/myfile")
mystring = myfile.readline()
while mystring <> "xyz"
linenumber += 1
messagebox.Show(mystring & " is on line " & linenumber)
end while
End Using
So if the contents of C:/myfile looked like this....
I
Love
Pie
Then you would get as output....
"I is on line 1"
"Love is on line 2"
"Pie is on line 3"
I have a text file that has multiple blank lines and Im trying to return all the lines between two of them specifically
so if I have a file that looks like this:
____________________________
1########################
2##########################
3
4########################
5##########################
6#######################
7
8#########################
9##########################
10#######################
11####################
12########################
13#########################
14
15##########################
----------------------------
I would like to grab lines 8-13. Unfortunately, it might not always be 8-13 as it could be 9-20 or 7-8, but it will however always be between the 2nd and 3rd line break.
I know how to trim characters and pull out singular lines, but I have no idea how to trim entire sections.
Any help would be appreciated, even if you just point me to a tutorial.
Thanks in advance.
The basic idea here is to get the entire thing as a string, split it into groups at the double line breaks, and then reference the group you want (in your case, the third one).
Dim value As String = File.ReadAllText("C:\test.txt")
Dim breakString As String = Environment.NewLine & Environment.NewLine
Dim groups As String() = value.Split({breakString}, StringSplitOptions.None)
Dim desiredString As String = groups(2)
MsgBox(desiredString)
Edit:
In response to the question in your comment -
Environment.NewLine is a more dynamic way of specifying a line break. Assuming you're running on windows - you could use VbCrLf as well. The idea is that if you were to compile the same code on Linux, it Environment.NewLine would generate a Lf instead. You can see here for more information: http://en.wikipedia.org/wiki/Newline
The reason I used Environment.NewLine & Environment.NewLine is because you want to break your information where there are two line breaks (one at the end of the last line of a paragraph, and one for the blank line before the next paragraph)
What I ended up doing was trimming the last part and searching for what I needed in the first part (I know I didnt include the searching part in the question, but I was just trying to figure out a way to narrow down the search results as it would have had repeated results). Im posting this incase anyone else stumbles upon this looking for some answers.
Dim applist() = System.IO.File.ReadAllLines("C:\applist.txt")
Dim findICSName As String = "pid"
Dim ICSName As New Regex("\:.*?\(")
Dim x = 0
Do Until applist(x).Contains("Total PSS by OOM adjustment:")
If applist(x).Contains(findICSName) Then
app = ICSName.Match(applist(x)).Value
app = app.TrimStart(CChar(": "))
app = app.TrimEnd(CChar("("))
ListBox1.Items.Add(app)
End If
x = x + 1
Loop
End If
How this works is that it looks through each line for the regex until it reaches first word in the breakpoint "Total PSS by OOM adjustment:"
If I have a string like input = "AA["
If Right(input, 1) = "[" Then Do stuff
The If statement returns false, even if I try converting things around to chars, etc etc. But if I do this is returns true:
Dim temp As String = Right(input, 1)
If temp = "[" Then Do Stuff
I like knowing little semantics like this, any idea why it comes out this way?
Or don't use Right at all since this is .Net
Dim s As String = "AAAAAAA]"
If s.Substring(s.Length - 1, 1) = "]" Then
Stop
End If
'or
If s(s.Length - 1) = "]" Then
Stop
End If
I've seen weird behavior like that when debugging.
In fact, today I had something simlar
Dim records As Integer
records = If(o.dr Is Nothing, o.ADO.rs.RecordCount, o.ADO.DS.Tables("tbl").Rows.Count)
That should work, using the rs.RecordCount when dr is nothing, otherwise using the Rows.Count. It didn't, records was ending up as zero. Rewrote it as a full if then/else block and it works.
It's never my first thought that the compiler/debugger/ide is messing things up, but you should keep it in the back of your mind for consideration: the programmers that wrote those programs are just as human and fallible as you or me.
It shouldn't. Are you sure you didn't have a typo? The result of RIGHT is a string, and if the input was truly "AA[" the IF will have passed.
I've never had VB act wonky on something like this.
If the code appears in a form, then the .Right property of the form overrides the string manipulation function. You need to specify the parent namespace - e.g. VisualBasic.Right - to ensure that you get the correct method.
I think you may have some kind of strange overload confusion occuring here.
You are specifiing "Right" (which could be calling a local "Right" function).
The function your implying is "Microsoft.VisualBasic.Strings.Right" in most of my code ends up being "Strings.Right" due to the global import.
I would try changing you code to the below and see if it still happens, in order to rule out some overload/scope confusion. (and/or the reduced "Strings.Right")
If Micosoft.VisualBasic.Strings.Right(input, 1) = "[" Then Do stuff