I am currently a computer science student, and am trying to teach myself how to lock a folder with a password. I have the lock working, but the problem is that the file is still readable. Anyone can open the file in edit and see pass=="PASSWORD", is there anyway that i am able to make the file unreadable as well as uneditable? Thank you!
Yes you can do it all you need to do is convert the readable text file into something called binary file or byte code file which other person can't read without processing it into the software or application you can do that trick.
Related
I am making a c version of pacman and am keeping my highscores in a separate .txt file called highscores.txt. In the program, after the completion of a game, it checks to see if the highscores file should be updated and writes over it if it should. The high scores view within the program reads the scores and names from the file. The issue is that it is very easy for someone to simply edit the .txt file and say they got any score they wanted. Is there a way to make it so that the file can only be written on by the program? This is in a Linux Red Hat environment.
I'd say just encript the file, then rename it something obscure.
An easy way will be to gzip it, and name as a file called "data" or whatever, so people couldn't guess it's gzip.
This method is easy to break once you know gzip is used, so a more secure way is to encript it using an encription key internal in your code.
Your best option is probably encryption. A good, quick study on Encoding vs. Encrypting vs Hashing
You could also look at other ways of storing the data. For example, something like HSQLDB or SQLLite, where you can create databases that have usernames and passwords available.
I come to you completely stumped. I do some side work for a company that uses an old DOS based program to input and retrieve data. This is a legacy piece of software, and they have since moved to either QuickBooks or Outlook for all of their address or billing related needs. However there have been some changes made, and they work with this database fairly regularly. Since the computer that this software is on, is running XP (and none of the other computers in the office can run it) they're looking to phase this software out for when the computer inevitably explodes.
TLDR; I have an old .csv file (roughly two years) that has a good chunk of information on it, but again it's two years old. I have another file called ml.dat (I'm assuming masterlist.dat) that's in the same folder as this legacy software. I open it with notepad and excel and am presented with information like this:
S;Û).;PÃS;*p(â'a,µ,
The above chunk of text is recognized much less within notepad or excel. It's a lot more of the unrecognized squares.
Some of the information is actually readable however. I can for example read the occasional town name, or person's name but I'm unable to get all of the information since there's a lot missing. Perhaps the data isn't in unicode or something? I have no idea. Any suggestions? I'm ultimately trying to take this information and toss it into either quickbooks or outlook.
Please help!
Thanks
Edit: I'm guessing the file might be encrypted since .dat's are usually clear text? Any thoughts?
.DAT files can be anything, they are usually just application data. Since there is readable text, then it is very unlikely that this file is encrypted. Instead you are seeing ASCII representations of the bytes of other content. http://www.asciitable.com/ Assuming single byte values, the number 77 might appear in the file somewhere as M.
Your options:
Search for some utility to load and translate the dat file for that application.
Set up an appropriate dos emulator so you can run this application on another box, or even a virtual machine running freedos or something.
Figure out the file format and then write a program to translate the data.
For #3, you can attach a debugger to the application to trace how the file is read and written. Alternatively you can try to figure out record boundaries (if all the records are the same size, then things are a little bit easier.) Then you can use known values to try to find field boundaries. If you can find (or reverse compile) the source code, then that could also give you insight into the file format.
1 is your best bet, and #2 will buy you some time so that you don't need that original machine anymore. #3 would likely be something to outsource.
If you can find the source or file format, then you just recreate whatever data structure was dumped to the file and read the file into it.
To find which exe opens it, you can do something like:
for %f in (*.exe) do find "ml.dat" %f -c
Assuming the original application was written in C then there would be code something like this to read the first record from the file:
struct SecretData
{
int first;
double money;
char city[10];
};
FILE* input;
struct SecretData secretdata;
input = fopen("ml.dat", "rb");
fread(&data, sizeof(data), 1, input);
fclose(input);
(The file would have been written with fwrite.) Basically you need to figure out the innards of the SecretData structure to be able to read the file.
There likely wasn't a separate utility used to make the file, dumping data and reading it back from a file is relatively easy in most languages.
After doing tons of research and nor being able to find a solution to my problem i decided to post here on stackoverflow.
Well my problem is kind of unusual so I guess that's why I wasn't able to find any answer:
I have a program that is recording stuff to a file. Then I have another one that is responsible for transferring that file. Finally I have a third one that gets the file and processes it.
My problem is:
The file transfer program needs to send the file while it's still being recorded. The problem is that when the file transfer program reaches end of file on the file doesn't mean that the file actually is complete as it is still being recorded.
It would be nice to have something to check if the recorder has that file still open or if it already closed it to be able to judge if the end of file actually is a real end of file or if there simply aren't further data to be read yet.
Hope you can help me out with this one. Maybe you have another idea on how to solve this problem.
Thank you in advance.
GeKod
Simply put - you can't without using filesystem notification mechanisms, windows, linux and osx all have flavors of this. I forget how Windows does it off the top of my head, but linux has 'inotify' and osx has 'knotify'.
The easy way to handle this is, record to a tmp file, when the recording is done then move the file into the 'ready-to-transfer-the-file' directory, if you do this so that the files are on the same filesystem when you do the move it will be atomic and instant ensuring that any time your transfer utility 'sees' a new file, it'll be wholly formed and ready to go.
Or, just have your tmp files have no extension, then when it's done rename the file to an extension that the transfer agent is polling for.
Have you considered using stream interface between the recorder program and the one that grabs the recorded data/file? If you have access to a stream interface (say an OS/stack service) which also provides a reliable end of stream signal/primitive you could consider that to replace the file interface.
There is no functions/libraries available in C to do this. But a simple alternative is to rename the file once an activity is over. For example, recorder can open the file with name - file.record and once done with recording, it can rename the file.record to file.transfer and the transfer program should look for file.transfer to transfer and once the transfer is done, it can rename the file to file.read and the reader can read that and finally rename it to file.done!
you can check if file is open or not as following
FILE_NAME="filename"
FILE_OPEN=`lsof | grep $FILE_NAME`
// if [ -z $FILE_NAME ] ;then
// "File NOT open"
// else
// "File Open"
refer http://linux.about.com/library/cmd/blcmdl8_lsof.htm
I think an advisory lock will help. Since if one using the file which another program is working on it, the one will get blocked or get an error. but if you access it in force,the action is Okey, but the result is unpredictable, In order to maintain the consistency, all of the processes who want to access the file should obey the advisory lock rule. I think that will work.
When the file is closed then the lock is freed too.Other processes can try to hold the file.
I have a number of files that contain data in a format I am not familiar with. All of the data files begin with the same byte sequence, presumably a file header, and the sequence is "URES". I'm assuming that these files are some kind of resource file, perhaps a collection of data or other files all embedded into one file; that's just a guess however.
Does anyone know what format this is/might be?
If so, how would I interrogate the file? Are there applications that let me open these kind of files? Do you know of any libraries or APIs that I can use to gain programmatic access the data?
Have you tried running the unix file command on it?
I know of one file format that starts with URES. It's a data file used for Watchtower Library. I have yet to understand the format myself.
maybe its something from the Universal Resource Editor (URE) that comes with the OS/2 Toolkit? just a guess...
it is from the watchtower library files and they use meps to encode it which is thier own librarys and encryption software so to crack it would take you a long time.
I am building a basic POS app for my cousin's pharmacy store so that he can dump the software he is currently using and save on license cost.All the medicines name which he has painfully entered into the software have been stored in a file with .d01 extension.
What i want is a way to read the contents of the .d01 file programmatically so that i can import the name of the medicines into my app.
The s/w from which my cousin uses is built in Foxpro(coz i see a lot of .cdx,.idx,.dbf files) and the file which i want to import is with .d01 extension. when i open the file in notepad it is something like this
http://img192.imageshack.us/img192/5528/foxpro.jpg
So I assume its somekind of database table or something. So can anyone please help me in reading this file, as i am not at all aware of foxpro.
Thanks a lot in advance to all those who take out time to reply.
hey guys thank you very much for replying so promptly.. I tried the solution suggested by Otávio and it worked, i will now write a small utility to read the dbf.
It has a good chance of being just a regular .dbf file. Copy it somewhere safe, change the extension to dbf and see if you can open it from foxpro.
Although it may have .cdx files, the actual paste of the file does not appear to be a visually recognizable header format of a VFP table... even if part of a database container. The characters around each column name don't look right. It may be from another language that also utilized "Compound Indexes". I even saw an article about Sybase's IAnywhere too. If worst-case scenario, and it is determined to be a possible fixed-length per row and no dynamic column sizes, you might take the file, strip off what appears to be the header and leave just the data and stream read it in based on how many constant characters are determined for the length. yeah, brute force, but just an option. Again, it doesn't LOOK like a VFP table.
BTW, what is the name of the software he is using... I'd look into that to see if any other type of indication to its source.
It looks sort of like a DBF file - maybe Clipper or something.