I have a question about a linked list. Is it possible to create a singly linked list from text files (the information content of each node of the list to be a text file)?
I am interested if I want, for example, that a singly linked list contains the names of text files, how, for example, when entering the name of a text file in the console, the contents of that file should be printed? Is this possible?
I have a big problem when understanding this kind of implementation. So I'm asking someone of you who has more experience with this kind of thing, if he's willing to help me?
I'm not looking for any implementation, can you just explain to me in words how it would work, because it's unclear to me. Also if there is any other idea to implement this, feel free to write.
Thanks in advance!
Best regards!
Related
VERY new to Python. I was programming in RPG and COBOL professionally decades ago so I have a programming background but haven't for years and now learning Python ......
I have two simple CSV files I open and work in. Then I want to combine the results and do more but it doesn't seem to let me.
(1) Currently I have defined a function (PROFDATA) to open first file (simple file of students marks from a professor). I access data and do some calculations and manipulations. Works great!
(2) I next define another function (TADATA) open the second file which has more marks for the students. I access do stuff and when I print, it gives me what I want from that file.
I want to combine my results from both files and then do more things but I don't seem to know best method. I know keeping them as FUNCTIONS means that the variables aren't available elsewhere.
Should I be writing data that I need from each file to a 3rd file?
Not sure of the best approach. Sorry up front as I know this must be a big time beginner question.
Tami
sorry for the messy title but I can't come up with something that really describes what's happening here. So I'm making a program that fetches .cue files for Playstation 1 roms. To do this, the program creates a SHA-1 hash of the file and checks it in a database. The database can be found in the "psx.hash" file in this repo. This has been working fine but I suddenly stumbled upon a very very nasty problem. There's plenty of files that have the same hash, because they are essentially the same file.
Let me break down the problem a bit. PSX roms are essentially cd files, and they can come in tracks. These tracks usually contain audio, and the .cue file is used to tell the emulator where each audio track is located [in the disc file]. So what I do is to identify each and every track file (based on their SHA-1 hash), see if they match the database, and then construct a link based on their name (minus the track text) to get to the original cue file. Then I read the text and add it to the cue, simple as that. Well, apparently many games use the same track for some reason? Exactly 175 of them
So... what can I do to difentiate them? This leads to the problem that I fetch the wrong cue file whenever this hash comes into play. This is the hash by the way: "d9f92af296360772e62caa4cb276de3fa74f5538". I tried other algorithms to see if it was just an extremely unlikely coincidence, but nope, all gave the same results. SHA-256 gave the same result, CRC gave the same result, MD5 gave the same result (by the same result I mean the same between files, of course the results of different algorithms for the same file will be different).
So I don't know what to do. This is a giant bug in my program that I have no idea on how to fix, any insight is welcome. I'm afraid I explained myself poorly, if so, I apologize, but I have a hard time seeing where I may not be clear enough, so if you have any doubts please, do ask.
It's worth noting that the database was not constructed by myself, but by redump.org, also, here's the code I'm using to retrieve the hashes of the files:
def getSha1(file):
hashSha1 = hashlib.sha1()
with open(file, "rb") as f:
for chunk in iter(lambda: f.read(4096), b""):
hashSha1.update(chunk)
return hashSha1.hexdigest()
The correct solution would be to construct the hash file in such a way that I can differentiate between track files for each game, but I ended up doing the following:
Sort the list of Tracks to have them ordered.
Get the first track file and retrieve the hash (this one will always be unique since it contains the game)
For every next track file that isn't Track 1, assume it belongs to the game before it. So if the next file is Track 2, assume it belongs to the previous file that had Track 1.
This nicely avoids the issue, although it's circumventing the bigger problem of not having properly formatted data.
I am attempting to write a C program that searches for duplicate files, groups the files, and then returns any files that are duplicates. The user can enter either a file path or specify files to check for using from the command line (argc). I am going to use stat() to traverse the system, and I know I need to use a hash table to bin the files. However, I am a bit lost on what to do to actually check if the files are repeats.
I know there are already programs that will do this for you, but this is an academic exercise that I need to complete. I am not looking for the coding answer, just a higher level answer on how I should go about solving the problem. Any feedback is appreciated, including any suggestions other than the ones I have listed above (again, I have to write this program from scratch).
Thanks.
We have a assignment and the teacher doesn't go into depth with explaining things so I'm a bit confused since I haven't really done much programming before. We have to write a program that when it's done being executed it's able to read its source file and can make another text file which is the same as its source file but the text file has a line number. My problem is I don't understand how to begin it. Could someone give me an example how to get started and what steps to take? I'm not asking for someone to do the programming for me just give an example. Thanks in advance.
Roughly the steps you'll want to take are:
Read each line of the input text file
Prepend the line number to the beginning of each line.
Write your modified lines into a new text file.
There's a lot of good information on how to read/write to files here, and string concatenation (for how to prepend the line number) here. You may also want to look into for loops so that you can hit every line in the input file.
There are really two parts to your question: "Who am I?" (what file are you) and "Write a copy of myself with line numbers"
The part that you describe above is the first -- "Who am I?" and for that, something external to your source code has to provide the info because the language itself can reside in any file.
Often, there is information available about what's being compiled made available by the preprocessor (just like it sounds, it's something that is run before compiling your source code). In this case, "preprocessor macros" commonly give you this sort of environmental data.
Take a look at this link for GNU C: https://gcc.gnu.org/onlinedocs/cpp/Standard-Predefined-Macros.html to start researching what is available under what conditions. Your compiler, if not gcc, should have similar docs.
Does anybody have an idea on how to extract all information from a compiled, record search program?
I think the program works by using a binary search. It was compiled and the database was in the program. The only way to see the records is to make a correct search.
Is there some way that I can bruteforce the program and extract all information?
The record is searched by the ID which starts with 1 and 10 digit long [ 1xxxxxxxxx ].
If you want to try, 1112700303 will work but I don't have the other numbers.
I've tried some Decompiler but I have no idea what I'm doing.
The program can be downloaded from here:
https://docs.google.com/file/d/0B9fwDRGBsrxBT3FiSFdaTnJZcUk/edit
Your help is appreciated as it will increase my knowledge and learn something new here :D
Though question. Is there no way to get hold of the source code (ask the author, search for the program name, ...)?
On Unix/Linux, the program strings extracts printable strings from a binary file. Doing that on x86 executables gives a long list of strings that are just instructions which happen to be ASCII strings, names of functions used by the program, ans other junk. Somewhere it lists initialized text data for the program (printf(3) formats, constant strings used), which in this case shows a bunch of names that look arabic, and some directory names. Perhaps searching for those could help.
This can probably be achieved by using Snowman. It might not get the exact source code you are looking for but enough to extract all the data you need such has the constant strings.