Read data in file line by line

Hello,
I got a question to ask you all about reading file.
How do I read a file data line by line and than print out to the screen?
For example, my file file.txt content is:
my line 1
my line 2
the program will read the 2 line and print out to the screen.
thanks very much

Thanks for your code but the code does not work. I can
compile the following code, but the content of the
file is not printed out yet.
Why is it so?Well, in addition to simply compiling the code, you have to execute it.
Also javajunior left open certain parts of the code, which you were supposed to finish. Like the exception handling and setting the filename variable. These are things that really only you can do.

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Reading data from file in EJB

I would like to read data from files in EJBS (Stateless Session Bean I think). I've heard that the EJB sepcifications don't allow to use the java.io package to access the filesystem. How can I resolve this problem? Possible solutions I've thought of are:
* Use a webserver to store the data
* put the files in a jar and access them using the getResource() in the classloader class
Could you comment on this plesae
greetings

The specification states:
"An enterprise bean must not use the java.io package to attempt to access files and directories in the file system.
The file system APIs are not well-suited for business components to access data. Business components should use a resource manager API, such as JDBC, to store data."
From this I understand I cannot acces files directly, but it does not specifiy I can't use the java.io package at all. It specifically says not to use the java.io package to acces files and directories, they don't say anything about using the classes for other use.
however, a litle lower the specification states:
"The enterprise bean must not attempt to create a class loader; obtain the current class loader; set the context class loader; set security manager; create a new security manager; stop the JVM; or change the input, output, and error streams.
These functions are reserved for the EJB Container. Allowing the enterprise bean to use these functions could compromise security and decrease the Container�s ability to properly manage the runtime environment."
I'm not sure how to interpret this, but I believe this rule makes my solution invalid.
Please comment on this,
thanks

JSF - Read a text file and diplay lines of text data on the web page

Hello,
For one of my projects, I need to display lines of text data on the web page using Java Server Faces Technology. The raw data could be from simple text files or sockets or anything. (Getting the data is not my issue but displaying is). Could anybody send answers with sample code. In servlet, one could do this by -
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException{
PrintWriter out = response.getWriter();
out.println("<html>");
out.println(DATA);
out.println(DATA);
out.println("</html>");
I am looking for similar solution.
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Thanks mjolinor. Works great!
Two questions.
1. Could you plz suggest how this could be modified so this code would read the file in or accept it from the pipeline instead of wrapping the (@' around the data?
2. Could you plz briefly describe some of the details of the code so I can further research and understand.
Thanks for your help.
Thanks for your help! SdeDot
1. It already reads in the file. The (@' .. '@) bits are just there to create a file using your test data to demonstrate that it works.
2. Not user what kind of "details" you want. There really isn't much there, and get-help on the cmdlets used should provide information on what's going on with them in that script.
[string](0..33|%{[char][int](46+("686552495351636652556262185355647068516270555358646562655775 0645570").substring(($_*2),2))})-replace " "

How to read *.dat type file

Hallo!
Can anyone help me with reading *.dat file using labview functions. Previously I've read them via matlab script, but after compiling to executable I could not read *.dat files. It might be because I'm working on LV 6i and in order to be able to read via matlab 6.5 I've paste matlabscript.dll from LV 7 to the main 6i place. However now I want to load this dats by using LV function and I can not achieve it.
I've already tried to use some examples from the help base and it doesn't work. There are slightly more then 2 milion samples in one coloumn in tis file.
Can anyone show me how to do that? I will appraciate
thanks
michal m
Attachments:
260701-1405V1.zip ‏1 KB

LabVIEw is always big endian (on any platform), but most other programs are little endian on intel machines (windows). See also the link Donald posted.
Your particular code still has a few bugs. Since you are reading U16, the number of data points is half the number of bytes in the file. You are trying to read twice as many and always get Error 4 (EOF encountered). To avoid this error, you need to divide the bytes by two for reading. Also watch out for correct representations, your record(s) indicator is I32 instead of U16, causing unecessary extra memory usage. ... and don't forget to close your file when done reading.
Message Edited by altenbach on 05-30-2005 09:19 AM
Message Edited by Support on 05-31-2005 08:59 AM
LabVIEW Champion . Do more with less code and in less time .
Attachments:
ReadU16Dat.png ‏6 KB

Reading data flow files

Hello,
I like to know if its posible to read dfd files, Dataflow files. I include an example of the file format.
Thanks in advance
B Bakels
Labview CLD , Engineer/Manager
Promedes and DSM
using LV 7.1, 8.0, 8.2, 8.5 and 2009 SP1
http://www.promedes.nl
Attachments:
04062008TW3001mm20mms.zip ‏353 KB

Hi bartb,
well, we know that you attached an example.
But we don't know the file format!
We can only guess:
-First 0x1270 bytes contain header data (identifier, version numbers, date/time strings, information on used hardware, channels, etc.). You have to know the format to get it into human readable form.
-Remaining bytes (starting at offset 0x1270) seem to contain 16bit data (according to used PCM-DAS16 hardware?). The data seem saved in big endian order...
The attached vi will load the data part of the example file - you have to interpret the data as I neither know the format correctly nor do I have knowledge what those data represent...
Message Edited by GerdW on 07-10-2008 02:09 PM
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome
Attachments:
ReadDFD_LV801.vi ‏47 KB

Read Data XML Files or Xml Schema

Hi
I need load info from XML files o schemas, using JavaScript
How is the conecction a xmlshema o xml file with JavaScript?
Thanks

This product does look to be ok, however it is missing a couple features that I would like the product to have.
I would like this product to be able to insert/update data across multiple tables. Being able to do such things as generate foreign key relationships.
It doesn't seem as though the XML being generated can be customized very easily. Some XML formats I deal with are very complex (such as X12/EDI).
I would really like a graphical mapper.
Here is a note from the doc:
Storing XML Data Across Tables
Currently the XML SQL Utility (XSU) can only store data in a single table. It maps a canonical representation of an XML document into any table or view. But there is a way to store XML with XSU across tables. You can do this using XSLT to transform any document into multiple documents and insert them separately. Another way is to define views over multiple tables (using object views if needed) and then do the insertions into the view. If the view is inherently non-updatable (because of complex joins), then you can use INSTEAD OF triggers over the views to do the inserts.
This product looks really good, I was hoping that Oracle had something comparable:
http://www.hitsw.com/products_services/xml_platform/allora.html

Read an ascii file line by line

I am new with CVI, and I need to read an ascii file with multiple lines in the following format:
at_test_2_to_13=0.861000
at_testabcd_9_to_21=0.712000
at_abdgx_5_to_8=0.892000
here is the code for writing in the ascii file:
sprintf(ctResult, "%s=%f\n", TestName1,result1);
WriteFile (fileHdl,ctResult ,StringLength(ctResult) );
At a later time, I need to read the text file, find the test name (for example "at_testabcd_9_to_21") and record the value after the "=" sign (in this case 0.712000). The number of lines in the text file is not fixed.
I am writing the data to the file with no problems, but I am stack in reading the data.
I would appreciate any help on how to write this code in CVI.
Thank you in advance
Solved!
Go to Solution.

As Wolfgang already proposed, you can use the ini-file library.
With this library, you can write the results in a structured manner and access an individual measurement by its name, without the need of reading every line above.
I also attached a sample project for what you asked.
Check the ini-file library help and samples for the other option.
S. Eren BALCI
www.aselsan.com.tr
Attachments:
AsciiRead.zip ‏2 KB

How to read data from a file in OSB

hi guys,
Recently, I've got a problem with reading file from specific location. I've actually followed this post OSB 11g - Read or Poll File in OSB - Oracle Fusion Middleware Blog, and then
I know how to read a file. However, it does not as expected. Because, I've found no way to read data from the file. Therefore, no chance to manipulate the data like assigning to a variable, or extracting ....
Hence, is there any way to read data from file by using proxy service in OSB ??? No Java code ???
by the way, supposed that there is no way to read data from a file in OSB. So, What purposes will the way in the post above be used for?
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http://jakarta.apache.org/poi/hssf/index.html
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How to read and writre file into remote machine in the network

HI Experts,
   i want to write the data and read data into file in remote machine(not in application server and presentation server).is it possible in abap.
thanks in advance
With Regads
Naidu

Hi naidu,
1. We can use this type of path
computername
folder
file.ext
2. We can use this in GUI_UPLOAD
   and it will run on presentation server,
   connect to
computer
   and read the file contents.
regards,
amit m.

Read data from a text file, one line at a time.

I need to read data from a text file, and display each line in a String Indicator on Front Panel. It displays each line, but I get Error 4, End Of Line, unless I enter an extra line of data in the file that I don't need. I tried Read From Text File.vi, made by Nat Instr, and it gave the same error.

The Read from Text File.vi reads data from a text file line by line until the user stops the VI manually with the Stop button on the front panel, or until an error (such as "Error 4, End of file") occurs. If an error occurs, the Simple Error Handler.vi pops up a dialog that tells you which error occurred.
The Read from Text File.vi uses a while loop, but if you knew how many lines you wanted to read, you could replace the while loop with a for loop set to read that many lines from the file.
If you need something more dynamic because the number of lines in your files vary, then you could change the code of the Read from Text File.vi to the expect "Error 4, End of file" and handle it appropriately. This would require unbundling the error cluster that comes fro
m the Read File function with the Unbundle By Name function, so that you can expose the individual error "status" and error "code" values stored in the cluster. If the value of the error "code" is 4, then you can change the error "status" from true to false, and you can rebundle the cluster with the Bundle by Name function. Setting the error "status" to false instructs the Simple Error Handler to ignore the error. Otherwise, pass the original error cluster to the Simple Error Handler.vi, so that you can see what the error is.
Of course, if you're not interested in what the errors are, you could just remove the Simple Error Handler.vi, but then you wouldn't see any error messages.
Best of Luck,
Dieter
Dieter Schweiss
Applications Engineer
National Instruments

How to read data from a specified line from a flat file

hi all
im having a filat file like as follows
(eg)
1.aaa
2.bbb
3.ccc
4.ddd
5.eee
using gui_upload i need to read the data from the flat file from the line number 2 into an internal table.
(eg)
2.bbb
3.ccc
etc
can any one help with this

Hi,
First u upload the data from flat file into the internal table.Once u uploaded read the internal table.
Read table itab index 2.
Thank u,
Manjula Devi.D

"read from measurement file" reads only first line of data

Hello,
I have a problem when trying to read a .lvm file through "Read from Measurements file" with the following block diagram
Problem: it reads only the first line of data from what I can see in the probe window,.
A part of the lvm file for reference.
I haven't used Labview in a long long time, I'm trying to figure out what I am doing wrong.
Thanks

Sorry meant to attach the lvm. Here it is. (Actually I had to put it in .txt because the forum wont let me upload a lvm file)
I unfortunately cannot share the full vi that record the data as I am not its owner/creator. I'll try to give as much info as I can with the relevant pictures attached, I hope it allows us to at least have an hint of where the problem might be.
(this is in a while loop)
In the stacked sequence, the other pannels are similar to the one shown here: value read fron a variable, converted to dynamic and a signal attribute is set. The "start recording" control operation is "switch when pressed".
Here are the properties of the set signal attributes
And here are the properties of the "write to measurement file"
Attachments:
NoTarget_full circle__Rx_-10-SAMPLE.txt ‏60 KB

I want to read the contents of a file to a text item line by line dynamical

I have created a timer
tm_id := FIND_TIMER('LOG_READING_TIMER');
If Id_Null(tm_id)
then
tm_id := create_timer('LOG_READING_TIMER', 1000, REPEAT);
else
set_timer (tm_id, 1000, REPEAT);
end if;
/* executed the shell script on application server */
host(v_command,no_screen);
and used below code for reading a file in when timer expired
DECLARE
v_file_name := '/home/log.txt' /* log created during running shell script */
BEGIN
v_infile := Text_IO.Fopen(v_file_name , 'r');
loop
Text_IO.Get_Line(v_infile,v_linebuf);
:CONTROL.item:= :CONTROL.item||v_linebuf||chr(10);
end loop;
WHEN no_data_found THEN
     Text_IO.Fclose(v_infile);
     delete_timer('LOG_TIMER');
END
I want to read a log file which is created while runnning shell script line by line
dynamically
Above code is reading the log filebut all the lines are shown at once.
I have to display
each line on the text item
and the next line line by line
Can anyone help me how to achieve this.
Thanks,
in advance

In when-button-pressed trigger
I have called a shell script on application server using host command
HOST('Path of script',NO_SCREEN);
Shell script writes some set of statements to log file on application server
Problem is to read the log file on to the multiline text item each line simultaneosly
while running the script.
Below is the procedure i have written to achieve this but below code is writing all the lines at once
after entire complete execution of shell script.
for example
shell script writes tolog file:
1. 'Loading of tables';
then loads the data
2. 'emailing data';
3. ...
4. ...
Below code writes
all the 4 lines at once
I want to see in frontend what is going on while running the script
by reading the log file data line by line
WHEN-BUTTON-PRESSED
tm_id := FIND_TIMER('LOG_READING_TIMER');
If Id_Null(tm_id)
then
tm_id := create_timer('LOG_READING_TIMER', 1000, REPEAT);
else
set_timer (tm_id, 1000, REPEAT);
end if;
/* executed the shell script on application server */
host(v_command,no_screen);
WHEN-TIMER-EXPIRED
and used below code for reading a file in when timer expired
DECLARE
v_file_name := '/home/log.txt' /* log created during running shell script */
BEGIN
v_infile := Text_IO.Fopen(v_file_name , 'r');
loop
Text_IO.Get_Line(v_infile,v_linebuf);
:CONTROL.item:= :CONTROL.item||v_linebuf||chr(10);
end loop;
WHEN no_data_found THEN
Text_IO.Fclose(v_infile);
delete_timer('LOG_TIMER');
END
While running the script on application server
I want to see the data from log file simulataneously on to the form when the data is written on to the log file
Please let me know if you need more details.
Thanks,
in advance

How to read from a file line by line

Hi
I am new to using LabView and was wondering how I could read data from a text file one line at a time and display this data one line at a time as well. I tried looking through the Reading from Text File . vi example but that just seems to be reading and displaying everything together.
Thanks
-Karan

Hi
My aim is to read text line by line and to then go ahead and display the last 8 reaad lines of code to give the impression of text falling down a screen. I tested the first while loop and that seemed to work fine. However, when I encounter an EOF, I would like the text already read to keep making its way down the screen and keep inputting NULL characters into the array to simulate the effect of the text falling down the screen which is why I created the second while loop. I tried to input the NULL characters using a box for ENUM constants. However, I kept getting an error saying the data types do not match. What would I need to do? For the display I plan on putting indicators next to the 8 places where the text would be stored which I have not done so far.
I am also attaching a copy of the error.
Thanks
-Karan
Attachments:
DisplayText.vi ‏40 KB
Error.JPG ‏89 KB
PictureOfBlock.JPG ‏120 KB

Read file line by line

Hi
Could somebody tell me how to read file line by line ? Namely my input file I want to read look as follow:
AAA 1, 1
12 222 12
AAA 2, 2
11 122 11
My output file should look as follow:
1, 1, 12
1, 1 222
1, 1, 12
2, 2, 11
2, 2, 122
2, 2, 11
I think the lines need to be stored in ArrayList, then I would like those lines to write to csv file, but how on read I can construct such output file? This is my code for reading file
public ArrayList readFile(String filename)
try
     BufferedReader in = new BufferedReader(new FileReader(filename));
     ArrayList list = new ArrayList();
     String lineS = null;
     while (in.ready())
      if ((lineS = in.readLine()).startsWith("")){
        String[] line = in.readLine().trim().split("\\s+");
        list.add(Integer.valueOf(line[0]));
        list.add(Integer.valueOf(line[1]));
        list.add(Integer.valueOf(line[2]));
     in.close();
     return list;
     catch (Exception e)
   e.printStackTrace();
return null;
Thanks

The rules for the conversion from input to the desired output are:
1. For each of the line with string take 2 integers for example 1, 1 from AAA 1, 1
2. Then repeat 1, 1 for each next number not containing any string, so if the line after AAA, 1, 1 has 12, 222, 12 then the output will look as follow
1, 1, 12
1, 1 222
1, 1, 12
3. Repeat the process (the pattern is the same 1 line with string 1 line with numbers)
Actually I am not sure how to perform that logic for such conversion as for now I am only able to list only the numbers but I have a problem to add numbers from the line having string in it.
STOP!
You should NOT be writing code if you are 'not sure how to perform that logic'.
You are getting ahead of yourself.
There is NOTHING to gain by trying to code a solution before you know what algorothm you need. Big mistake.
Should I use list or maybe if the patter for lines is the same array will be more sufficient?
NEITHER ONE!
Those are 'solutions' used to implelment an algorothm.
You do NOT yet know what algorithm you need to use so how can you possibly write code to implement the unknown?
How to perform logic to get the numbers from line having string and for the next lines having only numbers in order to structure it into desired output?
THAT is the question your thread subject should have.
Until you get the answer to it don't write any code,.
Do NOT try to automate what you can't do manually.
Write down, on paper or use an editor, the step by step 'logic' you need and walk through that logic from beginning to end until the 'logic' works and produces the correct result.
You just now have started to do that when you listed those rules above.
But you left some things out. Expand on that list of 'rules' and provide a little more example data. TPD has given you a good example. Reread what they said.
Did you notice they start by talking about 'tasks': what each task does and the order the tasks need to be performed.
That 'task list' has NOTHING to do with Java, C, or any other language: it is identifying the problem/algorithm. Until you have that coding is premature.

Read data in file line by line

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