How To Read The Last Few Lines Of A File In VB
Oct 21, 2011
We have a file to be read each time a code is run. Every 15minutes this file keeps growing by adding lines to its end.(Somebody does this beyond my control)
(My job:) Each hour I run the code, I need to read the new lines that are added to this file and store it into a database.
Usage:I am using the StringReader class in VB in which I am force to read the entire file atleast once(ReadLine) to reach the end.
Question:Is there a way in which I can Navigate to the end of the file and just read the last few lines each time?
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Aug 3, 2009
I am trying to make a script to spit command lines to a bat file to compress a bunch of files singly and then delete the original ones. I am sure that is easy to most of you, but I living a ____ trying to do this. A have a file list like this one belo, which was created with a command -- Dir /b /s /a-D N: > filelist.txt
[Code]...
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Oct 20, 2009
read lines in a file, split the lines and spit the result to another file
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Mar 17, 2012
below are a few lines from my text file(10929 lines)I need to read each line and insert into MS Access. each line is a column in my table and the record changes on every 8th line or to be more specific(on every 8th line you will see a number [1,2,3,4,5,6,7,8,9.....] this is where another record starts,
[Code]...
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Sep 15, 2009
I have a text file containing lines of data (File 1). I need to delete all the lines in another text file (File 2), which are found in file 1.So I could read file 2 line by line. And then once the line has been read, read file 1 line by line to search for a match. But that's going to be painfully slow.Or I could read file 2 into memory. And then read file 1 line by line and REPLACE the lines in file 2 with nothing, therefore deleting them. File 2 could be 100 mb, so I'm not sure about reading it all into memory.
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Mar 14, 2008
For the moment i use this code wich is reading only one line at time:
[Code]...
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Jan 13, 2012
I want to be able to read a certain line from a DAT file and have a return of only what is in that line.[code]...
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Oct 7, 2009
I a very large text document, I need to read some lines and at the end of each line, insert a text from the header of each page to he preceding lines.I have the following code the reads the file and displays it on a list box.Public Class Dialogs..[code]
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Mar 17, 2011
I have only been able to write data into the csv file.
[Code]...
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Jul 28, 2009
I want to use a FileStream and seek from the beginning of the file while moving forward in the file .01% of the file size at a time.
So I want to seek to a position in the file, read the entire line, if it matches my criteria I am done. If not, I seek ahead another .01.
C# is OK but VB.NET preferred.
I used to do it something like this in VB6...
FileOpen(1, CurrentFullPath, OpenMode.Input, OpenAccess.Read, OpenShare.Shared)
Dim FileLength As Long = LOF(1)
For x As Single = 0.99 To 0 Step -0.01
[Code].....
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Mar 24, 2011
I have this code now doing and that is creating my chart from data off a text file. The final task I need to be able to do, to complete my program is have a way to select how many days of data to populate my chats with via a Text Box input. I am thinking I will need to read the complete text file first to count how many lines are in it, then what ever is put in the text box it will take that many lines of data from the text file and populate the chart. For this to work correctly it would have to read the lines of the file back wards.(last line of file would be the first line..) e.g. textbox1.text = "7" then the chart would show only the last 7 lines of my data.
I was looking up examples of Counting the lines in the file, I think I am close here...
Dim fso As New FileSystemObject
Dim txt As TextStream
Set txt = fso.OpenTextFile(ReadChart, ForReading)
txt.ReadAll
Textbox2.text & txt.Line & " line(s)."
[Code] .....
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May 1, 2009
I want to make a program that reads the line of a file, and puts it into a text box, then reads the second line in that file, putting it in another text box... Say i only have a file with two lines, how can i do this?I have written a code, but it only works for the first line. Is there a preset function in Visual Basic that will allow me to read a certain line?
Imports System.IO.StreamReader
Dim AllText As String = vbNull, Lineoftext As String = vbNull
Dim Open_File As New OpenFileDialog ' Dim Open_File as a Open File Dialog
[code]....
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Feb 25, 2011
How can I read every eight lines of a text file, store it in arrays to load into a datagrid?
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Apr 13, 2012
i m using readallbyte method to read my log file. How to get first five bytes in every lines to do the comparison?
Dim data() As Byte = System.IO.File.ReadAllBytes("c:1.txt") 'read log file in bytes
Dim lines() As String = System.IO.File.ReadAllLines("c:1.txt") 'read log file in lines
Let's say:
For i=0 to 100
If lines(i).startwith("212330") Then
'code
End If
Next
The value 22330 is read from the file in byte. But i not sure whether can find the byte value by using readalllines method.
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Mar 4, 2012
I am using vb 2010 and a windows form in my Web Browser project. In my favorites bar I need to be able to import my users favorites (that he may add) through a .txt file. I realize one way of doing this is creating multiple files stored in one master folder and reading the whole file of each which would contain the URL, but I would much rather have them all in one .txt file, but for that to happen i must read line by line from that file to import the favorites. Therefore, my question is how can I code my project to read through a .txt file line by line and return each line in possibly an array? "We are what we repeatedly do. Excellence, therefore, is not an act but a habit."
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Oct 12, 2009
I need to read the text file and take only lline from 1 to 20 and writ it in another text file. Is that possible to do, How can we do this?
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May 4, 2011
I need to read lines from file. Now my code is like this:
Sub data()
Dim reader As New IO.StreamReader("log.txt")
For i = 0 To 1500
date(i) = reader.ReadLine
Next i
End Sub
Now if some user will change add or remove the data from this file, it will end up with error or sth. I also tried to write sth like this:
Open "C:in.txt" For Input As intInFile
But there appears an error, that open is not declared and IO functionality is microsoft.visualbasic namespace. I added this name space (at the top: Imports Microsoft.VisualBasic), but this error still occurs.
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Sep 24, 2010
How can I read a text file 10 lines at a time?
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Mar 11, 2010
I would like to read a file and display certain lines ( like from line 5 to 10) in a label. i know how to read the file line by line but not the specified line i want.
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Jan 11, 2011
i wanna read lines from a text file randomly until all the lines are read & wanna set a time interval in each two words apart. think a piece of code to do that in vb.net?
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Mar 26, 2009
I'm trying to do is to read the lines from a text file, and transfer them to an array.[code]...
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Jul 1, 2009
VS 2008 Read specific lines from txt file?
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Dec 16, 2010
i want 2 textboxs to read from 2 different lines in my textfile.how can this be done?
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Feb 13, 2009
I have a function that is reading a sequential file and storing it into an array by using the delimiters of
The first record appears correctly however, the second element in the array has two null lines at the beginning and at the end of the record. [code]...
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Jul 23, 2010
I got the following code to read an XML file: [Code] Obviously the count limits the amount of lines that it reads. But how do I get it to read all the lines in the file? Ive tried removing the And (count <20) but when I run the program nothing happens.
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Nov 3, 2010
I'm trying to read a text file with multiple lines and then display it in a textbox. The problem is that my program only reads one line.
Imports System.IO
Imports Microsoft.VisualBasic.FileIO
Public Class Form1
[code]....
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Nov 15, 2009
I am trying to read from a file that was created with a stream writer the names line from the text file that contains data for name, phone number, pager number, cell number, voice mail, and email.What I need to do is read and load the names from the file into a list box, and then from the list box be able to choose each name and have the information (phone, pager, cell, etc.) show up in text boxes that goes with the specific name.
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Jun 23, 2011
I'm trying to read lines from a file and split them into two words contained in a two dimensional array. The file looks something like this:
dog cat
red blue
orange green
night day
[code]....
'When I run it, it highlights the following line and says Object reference not set to an instance of an object
pos(i, 0) = value(0)
pos(i, 1) = value(1)
i = i + 1
Loop
[code]....
why I'm getting this error?
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Apr 2, 2010
I've got myself a CSV file with the following contents:
1,The Compact,1.8GHz,1024MB,160GB,440
2,The Medium,2.4GHz,1024MB,180GB,500
3,The Workhorse,2.4GHz,2048MB,220GB,650
It's a list of computer systems, basically, that the user can purchase.I need to read this file, line-by-line, into an array. Let's call this array csvline().The first line of the text file would stored in csvline(0). Line two would be stored in csvline(1). And so on. (I've started with zero because that's where VB starts its arrays). A drop-down list would then enable the user to select 1, 2 or 3 (or however many lines/systems are stored in the file). Upon selecting a number - say, 1 - csvline(0) would be displayed inside a textbox (textbox1, let's say). If 2 was selected, csvline(1) would be displayed, and so on.
It's not the formatting I need help with, though; that's the easy part. I just need someone to help teach me how to read a CSV file line-by-line, putting each line into a string array - csvlines(count) - then increment count by one so that the next line is read into another slot.So far, I've been able to paste the numbers of each system into an combobox:
Using csvfileparser As New Microsoft.VisualBasic.FileIO.TextFieldParser _
("F:folderprogramnameprogramnameinDebugsystems.csv")
Dim csvalue As String()[code]......
But this only selects individual values. I need to figure out how selecting one of these numbers in the combobox can trigger textbox1 to be appended with just that line (I can handle the formatting, using the string.format stuff). If I try to do this using csvalue = csvtranslator.ReadLine , I get the following error message:
"Error 1 Value of type 'String' cannot be converted to '1-dimensional array of String'."
If I then put it as an array, ie: csvalue() = csvtranslator.ReadLine , I then get a different error message:"Error 1 Number of indices is less than the number of dimensions of the indexed array."
Structure systemstructure
Dim number As Byte
Dim name As String[code]............
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May 12, 2009
i have 5 textboxes in a form. I have a streamwriter that writes all of their text to on text file like this:
Code:
Dim xfile As String = Application.StartupPath & "/Set.txt"
If File.Exists(xfile) = True Then
Dim writex As StreamWriter = New StreamWriter(xfile)
[code]....
I was wondering how to get the text under the each number and place it in the corresponding textbox.
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