Read A Very Large File Line By Line Instead Of Loading It All?
Feb 25, 2009
the best method to read a huge file? I'm guessing its with "stream"?It's like a 200mb file.I need to read each line and do something if the line contains a search string.
Code:Imports System.IO
Public Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim strFile As String = "c:
[code].....
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Oct 7, 2011
I need to read the second-to-last line of a very large log file.
I can't read the entire thing into memory, count lines, etc etc. I can't use Filestream.Setlength because that needs readwrite access and the log will be opened by another application. And it has to be fast. However, the line ends in a cr/lf meaning the last line is actually empty. Been struggling with this all day, and its hurting my head! Not good on a Friday!
I have a function that can read the last line but can't get it to go one line up. I can get it to read characters from the end of the line, but that's not much of a help with a variable length line!
Maybe fs SeekOrigin would work as it could run backwards looking at an example from MSDN - need to get the data before the last cr/lf and end at the next one... hmmm... problem is that that example also writes the text backwards as well.
I'm monitoring the log for particular entries for issues that are causing us grief at the moment.
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Oct 14, 2011
what i need to do is open a txt file, read line by line, decode each line into an array and display. Now all works ok apart from one line.
sTextLine = objReader.ReadLine() <-- Value of string cannot be converted.
full code here
-------------
Dim objReader As New System.IO.StreamReader(sOpenFile.Text)
Dim sTextLine As New ArrayList()
Dim sText As String = ""
Dim i As Integer = 0
[code]....
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Aug 15, 2011
I have a data file which I am de-compressing and then reading line by line.This includes data which is then read by my function which is split into sperate bits then inserted into a database.My reader is currently taking ages. (largest file being 1.8GB)I am using:
Code:
' File exists, read file.
Dim objReader As New System.IO.StreamReader(fileName)[code]....
Is there a quicker way to do this? And possibly a progress bar to show how far it is through the file?
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Mar 17, 2010
I'm trying to read a file line by line into an array but It skips the item at index:3 I have it msgboxing just to make sure and it wont even touch it.
Dim Btn As Button = DirectCast(sender, Button)
Dim path As String = Application.StartupPath & "Libraries" & Btn.Text.Replace(" ", "_") & ".ipt"
Dim i As Integer = 0
Dim lines As String() = IO.File.ReadAllLines(path)
[code]....
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Aug 30, 2010
I like search a file TXT with this contains:
Name "Paul"
Age "11"
City "Chicago"
my question is: Its possible get a string "Name" and give me the value "Paul"? I have this function for get strings:
[code]...
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Feb 20, 2012
Why can I only see the first line split in the listboxes repeated 4 times? I can not see all the lines of the Dictionary.[code]...
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Jun 22, 2009
I have code that reads the whole file, not line by line.
Here is the code:
FileOpen(1, filename, OpenMode.Input)
Do While Not EOF(1)
datatodisplay = LineInput(1)
Loop
FileClose(1)
I would like to know how I can read the file line by line and then add all results into an array list.
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Dec 26, 2009
I need to read a xls/xlsx/ods/txt file line by line,to get a column name of file .how to read a file line by line in vb.net?
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Sep 19, 2010
Ok, I saw this code on the net
Dim sFileName As String
Dim srFileReader As System.IO.StreamReader
Dim sInputLine As String
sFileName = "D:UsersArbenDesktopSerieA.txt"
srFileReader = System.IO.File.OpenText(sFileName)
[Code]...
under the code I pasted at the top, but I get the text on line1 in all labels, like all labels become 1, while the text should be 1, 2, 3 and so on. So anyone can help me do that, each label gets the value of the next line in the txt file
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Jan 16, 2011
how to read text from a listbox line by line and put current line in a label?
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Mar 25, 2011
I have a text file like below;
606;16
101 GAZ MET.MED. - VIC.BRANESTI 2011-01-11T11:00:00
102 BRASOV - TARGU MURES 2011-01-11T10:30:00
[code].....
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May 4, 2009
I am trying to read a PDF file line by line using PDFBox.This is the first time I have ever attempted to do this with a PDF so I am not sure what I was expecting but I thought I would end up with some "mark up", which I could use to parse the lines I was looking for out of the file.
Anyway it didn't work out the way I had planned and I am not sure if that is because I am using the wrong tool or not using the right tool correctly.I managed to extract the text but I didn't really see any mark up that would be usefull to parse the file. Does anybody have any experiece with extracting test from PDFs. What tool(s) do you recomend?
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Mar 29, 2012
I am quite new in VB NET, after VB. and unfortuantely I had to copy paste and merge the code fragments from some tutorials.
I have a folder including 200 eng files which can be opened by notepad. And each file has around 4000 row; with 60 field seperated by coma. I need to read specific row-field value at each files.
Now what I can is:
a) reading individual txt files and find specific value
b) listing all of the files in the folder
c) I can merge (a) and (b) and read all the files automatically, but since ram is continuously increasing, and at one point (sometimes 163, sometimes 169, or 170. files or something) it gives an error as "System.OutOfMemoryException". My ram is 4 GB and when I get this error the ram is increasing to more than 3 GB.
1- Could it be happen because of being eng files instead of regular txt files?[code]...
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Dec 14, 2009
how can I read data in a file line by line..for eg in my project I have to store movie information in a file and every movie's info has to be in one line..this is my code for file
Private Sub btn_Read(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
sw.Close()
fs.Close()
fs = New FileStream(filetxt.Text, FileMode.Open, FileAccess.Read)
[code]....
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Aug 21, 2011
how to read a simple text file line by line like when you're writing to a file with System.IO.StreamWriter where you write to the file line by line.
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Apr 11, 2012
if i want to read from txt file called "students" line by line and after reading each line, I want to split the information To make sure a user or not
[Code]...
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Jan 25, 2010
how to load a word document ,line by line in Microsoft vb 2008?
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Apr 4, 2012
The file is a UTF8 text files.
Each characters has varying number of bytes and each line has varying number of characters.
Does vb.net has table of line numbers to byte location function or something like that?
Also after that how to read that?
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Dec 1, 2011
How would i go about reading a file Line by Line that within that line The values are delimited by " Example of the data:
"bob" "cat" "1243"
"steve" dog" "6789"
I've started this with this code but not sure how to go about the next stage:
Using MyReader As New _
Microsoft.VisualBasic.FileIO.TextFieldParser(My.Application.Info.DirectoryPath & "Records28112011.jd")
MyReader.TextFieldType = FileIO.FieldType.Delimited
[code]....
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Jun 26, 2009
Is there an easy way to insert a line into the very beginning of a large file?I want to insert an XML header line into XML files that my program processes (These files can be very large, so reading it via bitstream and writing it out is not a good option).
File.AppendText makes it very easy to append lines to the end of a file, but I don't see anything for inserting text.I wonder how does say Access work in processing say a 50 meg access database file? There must be a similar process where you can insert data anywhere inside a large file.
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May 16, 2012
How do i read through a textfile line by line checking for and removing duplicate values?
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May 8, 2011
I am developing a program where i will download and save an xml file from a url as abc.xml. I open the abc.xml in a datagridview with a dataset without problem.I am confused how can i read raw per raw the datagridview and assign the data in a database table? i am using vb 2008 + msde2005 express.I show the whole content of the xml file in the datagridview with the following [code]I dont know how to create a loop where i can read the datagridview line by line save data in variables (ex.strings) and save it in a databese table?
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Jul 9, 2011
I have a text file with an unknown number of lines. I want to read this file line by line and send each line's text in a check list box. But how am i gonna do that when i don't know how many lines exist in text the file? [code]The code above reads only the first line. I tried to do it as in vb6 using while not eof(but here i don't know what to write cause my file isn't opened in a certain channel).
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Jul 11, 2010
i have a text file which contain 3 lines "ha 0.21, hb 0.35, hc 0.44" I want to read the file and get the second character of every line, which are "a, b and c" and assign them to array. My code below able to read the file but only able to get the last line of text. May i know how to do to get every second character and assign to array?
Dim FILE_NAME As String = "C:Test.txt"
Dim TextLine As String
If System.IO.File.Exists(FILE_NAME) = True Then
[Code]....
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Jun 6, 2011
i have an apllication that reads from a textfile. (the textfile is .sql)[code]i use streamreader the read the txt file. if i only have line the app doesnt crash but more the one line is getting stuck.so can i read each line seperate and procces that line.
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Oct 10, 2011
Im trying to create a program which can edit/read the textbox line by line.[code]...
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Nov 17, 2009
I have a multiline textbox from which I would like to read each individual line and store it in an array. I don't want to store each carriage return, I want the line itself.I have been using this, but it only records lines followed by carriage returns.
Dim arra() = txtReceipt.Text.Split(Environment.NewLine)
Here is a visual example: [URL]From that top right textbox, I would want arra(0) to be "Type some stuff here (and hit the return and" and arra(1) to be "tab keys...)"
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Sep 6, 2010
I need to load a .txt to a listbox then how to read line by line?
then import the line which is being readed to Textbox
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Jun 1, 2009
I have a string that contains many lines.It is someething like:
I
want
to
be
a
millionaire.
I need to read this string line by line, that is to assign line 1 of the string to a certain variable, line 2 to another, and so on.Do you know how that can be done?
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