Reading few files at a time

I want to be able to read just few files at a time in a given directory. File Class provides .list() but it gets all the files or if I use FileNameFilter then based on file name - still it will try to read all the file names. But what I want is to read few files. We have 3 million files in a directory, how can I read 100 or say 1000 files at a time. File.list() is going to try to load all the file names at once.

How to do that without reading the entiredirectory?
JVM doesn't have to load the entire list to do this.
It could be implemented using native OS calls. I
don't know if they exist or not or if JVM has
bindings to them, etc. But I was hoping there was
something there. I guess not."...getting a list of files that match some search criteria?" (as you said) requires something (Java or an underlying native OS) to acquire the entire directory listing and then select from the listing, in some manner. And this is what the OP didn't want to do.

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Reading one file at a time using File Adapter

I am using a File Adapter which polls every minute to read files from a Folder. This process picks up all the files in that folder. What I want to achieve is that the File Adapter should read one file at a time. Is it possible to force it to wait for a few seconds before reading the Next file in the Folder. Or is there a solution to what I am trying to achieve? Any help would be appreciated.

public static char readChar() {
int ch;
char r = '\0';
boolean done = false;
while (!done) {
try {
ch = System.in.read();
r = (char) ch;
if (r == '\r') {
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Try this as an method and then use it..
This code will read will be in response untill you hit the return key but will take only the first character....

Reading two files at a time

Hi,
My sender system sends two files
1.Header
2.Item
I need to read both the files at a time.
If only both the files are present in the directory,i want pick the files otherwise not.
How can i do this validation in XI??
Thanks.
Rushikesh

Hi Rushikesh,
YOu can do this in two ways,
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BPM:
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Edited by: VenkataPrabhakar Teegavarapu on Oct 21, 2008 11:32 AM

Reading excel files in real time

Hello,
I would like to have a labVIEW program which permits to read several excel files, and collect all data in a single excel file.
I know that it is possible to write a program which can read multiple files.
But I would like to know that if its possible to read files in a real time:
for ex. each time there is a new excel file to read, the LabVIEW program read it automatically and add its data to the final file?
Thank you and bests regards

As Sam notes, it is certainly possible to merge Excel Files (I've done it, myself). An oft-repeated Best Practice for Program Development, which I didn't understand nor start following until quite recently, is "Write the Documentation First". In this case, you want to think carefully (and specify in a Document, which tends to "clarify your thinking") a number of issues:
Where will you look for the Excel Files to be merged? [Hint -- it's much easier if they are all in the same Folder).
Where will you save the Merged File? Will it be in the same Folder as the Source Files?
How will the Merged File be named? This can have an interaction effect with the previous points.
What is the structure of the Source, and of the Merged, File? Is it "obvious" how the Merge is to take place?
Related to #4, are there Headers? Multiple WorkSheets?
How do you know when it is time to Merge? Are you checking for new files periodically? How often?
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Write yourself a Document, show it to us, and if you have ideas on how to do this, give it a try and show us your code -- we'll try to provide assistance if you "get stuck".
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Why does my quicktime player verson 10.2 somtimes read avi files and other times it wont recognize them?

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Whats up with that ??? Any help will be most appreciated!

AVI is a container just like MKV, WMV, MOV, and MPEG. It is possible to use many different compression formats aka. codecs in an AVI container.
Think of the container - AVI as being an envelope, and the compressed video in it as a letter. The letter may be in a language you cannot read even though you know how to open the envelope.
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Can only copy few files at a time from DVD

I received two DVDs from our wedding photographer and when trying to copy a DVD with about 400 images to my Mac it always fails somewhere in the process, with the drive making a disconcerting scratching noise just before it stops. Once it fails the only option is to force quit Finder and then force restart. Tried copying all the files at once from the second DVD and same result.
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MATSHITA DVD-R UJ-867:
Firmware Revision: HA13
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Burn Support: Yes (Apple Shipping Drive)
Cache: 2048 KB
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Thank you for the replies. After using both my laptop and another laptop to copy the files we finally got them all copied. Both laptops exhibited similar behavior on both DVDs so it probably is the type of DVDr (. The scratching was not the laser motor seeking to read the disk, rather it was relative to the spinning speed of the dvd, as if it were warped or had a piece sticking off of it, and it scratched more the faster the DVD spun, but the DVD looked to be fine. I have since tried other DVDs and they work fine so still not sure what the problem was but the files are on my HD now so that problem is solved.
-Lewis

Read txt file 1 char @ time cnvrt to uppercase problem

I am trying to get the following 2 problems solved. My input file is below and my output is below along with the code.
Can anyone fix this and explain what I am doing wrong? Thank You in advance!
(1) Any string of two or more blanks symbols is replaced by a single blanks.
(2) All sentences start with an upper case letter.
Input A://DataIn.txt = How me? you good.
Output A://DataOut.txt = H o w m e Y U G O . ��
import java.io.*;
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*(1) Any string of two or more blanks symbols is replaced by a single blanks.
(2) All sentences start with an upper case letter.
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twoTimer.connectToOutputFile();
twoTimer.readInput();
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String inputFileName = getFileName("Enter input file name: A://DataIn.txt");
try
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new DataInputStream(
new FileInputStream(inputFileName));
catch(FileNotFoundException e)
System.out.println("File " + inputFileName
+ " not found.");
System.exit(0);
public void connectToOutputFile()
String outputFileName = getFileName("Enter output file name: A://DataOut.txt");
try
outputStream = new DataOutputStream(
new FileOutputStream(outputFileName));
catch(FileNotFoundException e)
System.out.println("Error opening output file "
+ outputFileName);
System.out.println(e.getMessage());
System.exit(0);
private String getFileName(String prompt)
String fileName = null;
System.out.println(prompt);
fileName = SavitchIn.readLineWord();
return fileName;
//===========================================================================
public void readInput()
char prevChar = ' ';
try
char nextChar;
String result = "";
boolean done1 = false;
boolean done2 = false;
char next;
do
next = (char) (inputStream.read()); // <== Read input 1 Character @ time
if (next == '\n')
done1 = true;
if (next == ' ' && next == prevChar)
prevChar = next;
else
if (next == '.' || next == '!' || next == '?')// <== Capitalize next input Character
do
next = ' ';
outputStream.writeChar(next);
next = (char) (inputStream.read());
if (next == '\n')
done2 = true;
next = (char) (inputStream.read());
// next = (char) (inputStream.readNonwhiteChar()); ?????????????
if (next == '\n')// <== never gets to end of file
done2 = true;
outputStream.writeChar(Character.toUpperCase (next));
prevChar = next;
while (!done2);
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outputStream.writeChar(next);
prevChar = next;
while (!done1);
catch(EOFException e)
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System.out.println("Do Nothing Here");
catch(IOException e)
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inputStream.close();
outputStream.close();
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System.out.println("Error closing files "
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This line looks fishy:
if (next == ' ' && next == prevChar)
prevChar = next;Try:
if (next == ' ' && next == prevChar)
next = "";That should take care of the extra blanks, though I didn't test it myself, and could very well be wrong.
Not sure about the uppercase, though I imagine it must be reading the ToUpperCase every time after the first period.

Reading log file and calculating time between

If someone could help me with this one, I would be very grateful.
I have a log file and I need to search a string that contains a start time and end time (eg. <time="11:10:58.000+000">). When I have these two values, I need to measure the time that has been elapsed between these two (from start to end).

$Path="C:\Times.log"
remove-item $Path
Add-Content $Path '<time="11:10:58.000+000">'
Add-Content $Path '<time="12:10:58.000+000">'
Add-Content $Path '<time="13:10:58.000+000">'
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Add-Content $Path '<time="16:10:58.000+000">'
Add-Content $Path '<time="17:08:28.000+000">'
$File=Get-Content $Path
$StartTime=$Null
$EndTime=$Null
$ElapsedTime = $Null
ForEach ($Line in $File)
If ($Line.Contains("time="))
$Position = $Line.IndexOf("time=")
$TimeStr =$Line.SubString($Position+6,8)
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$StartTime = $TimeStr -As [System.TimeSpan]
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$EndTime = $TimeStr -As [System.TimeSpan]
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"StartTime=$StartTime EndTime=$EndTime ElapsedTime=$ElapsedTime"
$StartTime = $Null
Gives this output
StartTime=11:10:58 EndTime=12:10:58 ElapsedTime=01:00:00
StartTime=13:10:58 EndTime=15:13:38 ElapsedTime=02:02:40
StartTime=16:10:58 EndTime=17:08:28 ElapsedTime=00:57:30

CSV file reading using UTL_FILE at run time

Hi,
I have to read CSV file using UTL_FILE.
but Folder contains Many CSV files.
I dont know there name.So i have to read csv file at run time.
Please let me know how should we achieve this?
Thanks

place the following in a shell script, say "list_my_files.ksh"
ls -l > my_file_list.datthen run the shell script using dbms_scheduler;
begin
dbms_scheduler.create_program (program_name   => 'a_test_proc'
                              ,program_type   => 'EXECUTABLE'
                              ,program_action => '/home/bluefrog/list_my_files.ksh'
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/then open "my_file_list.dat" using UTL_FILE, read all file names and choose the one you require.
P;

Design for reading mutiple files

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hi , my problem statement is i have to read multiple files at same time and send the content to a C++ system Make a class called TaskFileReader which implements Future; this class is specializing in reading a file.
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Trying to use a new, larger external hard drive for my Time Machine backup. However, every time I start the backup, it gets started then fails. And, I can't delete the few files that did save on the external. Sort of a catch 22. Any ideas?

Trying to use a new, larger external hard drive for my Time Machine backup. However, every time I start the backup, it gets started then fails. And, I can't delete the few files that did save on the external. Sort of a catch 22. Any ideas?

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My Time machine has stopped backing up saying there are some read only files.

My Time machine has stopped backing up and says that ther are some read only files preventing this. What steps do I need to take to fix it?

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Post the log text, please, not a screenshot. If there are runs of repeated messages, post only one example of each. Don't post many repetitions of the same message.
When posting a log extract, be selective. Don't post more than is requested.
Please do not indiscriminately dump thousands of lines from the log into a message.
Some personal information, such as the names of your files, may be included — edit that out, too, but don’t remove the context.

How to read several text files at a time

Dear all
Read and write one text file is not a problem, but what confusies me is how to read several text files at one time, in the meanwhile,
is it possible to display the name of the text file?
For example, assuming I want to load file" cha 1, cha 2 , cha 3, " at one time and show their names, how to hadle with it
I have reviewed some files and it is not helpful

Either with a 'for' loop like in the lib you have attached, or like this attached VI
that's it
Message Edited by devchander on 05-30-2006 05:11 AM
Attachments:
MULTIPLE READ.vi ‏44 KB

Read a file at a fixed time of day using PS in OSB

I have a proxy service which read a file, now I want to read that file at a fixed time in a day(suppose 12pm every day).
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Pls suggest!

Re: How to implement in OSB: Scheduling, Timers and Custom properties
Regards,
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Read one word at a time from a text file

I want to read one word at a time from a text file as it is done by "scanf &s" function in text based programme. It is not possible by " read from text" function. Suggest me function or method to solve this.

The simplest way is to use the spreadsheet string to array function with the space character as the delimiter.
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If you need something more sophisticated that splits based on whitespace (e.g. tab, new line) then you'll probably need to do something with searching the string for these characters (e.g. using a regular expression) and then splitting them yourself into an array.
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Certified LabVIEW Architect, Certified TestStand Developer
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Reading few files at a time

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