I'm working on a program in pike and looking for a method like the endswith() in python- a method that gives me the extension of a given file.
Can someone help me with that?
thank you
Python's endswith() is something like Pike's has_suffix(string s, string suffix):
has_suffix("index.html", ".html");
Reference:
http://pike.lysator.liu.se/generated/manual/modref/ex/predef_3A_3A/has_suffix.html
extract the end of the string, and compare it with the desired extension:
"hello.html"[<4..] == ".html"
(<4 counts from the end of the string/array)
If you want to see what the extension of a file is, just find the last dot and get the substring after it, e.g. (str/".")[-1]
If you just want to check if the file is of a certain extension, using has_suffix() is a good way, e.g. has_suffix(str, ".html")
I want to make program that read file name in current directory and sort file name by added date in C programming.
I learned how to print file name by using DIR.
But I can't find any answer how to sort file name from it.(DIR)
Could you please teach me how to solve?
Best regards,
you can get the file names. Refer to this, https://msdn.microsoft.com/en-us/library/kda16keh.aspx
sort the string array.
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.
just had a general question about how to approach a certain problem I'm facing. I'm fairly new to C so bear with me here. Say I have a folder with 1000+ text files, the files are not named in any kind of numbered order, but they are alphabetical. For my problem I have files of stock data, each file is named after the company's respective ticker. I want to write a program that will open each file, read the data find the historical low and compare it to the current price and calculate the percent change, and then print it. Searching and calculating are not a problem, the problem is getting the program to go through and open each file. The only way I can see to attack this is to create a text file containing all of the ticker symbols, having the program read that into an array and then run a loop that first opens the first filename in the array, perform the calculations, print the output, close the file, then loop back around moving to the second element (the next ticker symbol) in the array. This would be fairly simple to set up (I think) but I'd really like to avoid typing out over a thousand file names into a text file. Is there a better way to approach this? Not really asking for code ( unless there is some amazing function in c that will do this for me ;) ), just some advice from more experienced C programmers.
Thanks :)
Edit: This is on Linux, sorry I forgot to metion that!
Under Linux/Unix (BSD, OS X, POSIX, etc.) you can use opendir / readdir to go through the directory structure. No need to generate static files that need to be updated, when the file system has the information you want. If you only want a sub-set of stocks at a given time, then using glob would be quicker, there is also scandir.
I don't know what Win32 (Windows / Platform SDK) functions are called, if you are developing using Visual C++ as your C compiler. Searching MSDN Library should help you.
Assuming you're running on linux...
ls /path/to/text/files > names.txt
is exactly what you want.
opendir(); on linux.
http://linux.die.net/man/3/opendir
Exemple :
http://snippets.dzone.com/posts/show/5734
In pseudo code it would look like this, I cannot define the code as I'm not 100% sure if this is the correct approach...
for each directory entry
scan the filename
extract the ticker name from the filename
open the file
read the data
create a record consisting of the filename, data.....
close the file
add the record to a list/array...
> sort the list/array into alphabetical order based on
the ticker name in the filename...
You could vary it slightly if you wish, scan the filenames in the directory entries and sort them first by building a record with the filenames first, then go back to the start of the list/array and open each one individually reading the data and putting it into the record then....
Hope this helps,
best regards,
Tom.
There are no functions in standard C that have any notion of a "directory". You will need to use some kind of platform-specific function to do this. For some examples, take a look at this post from Cprogrammnig.com.
Personally, I prefer using the opendir()/readdir() approach as shown in the second example. It works natively under Linux and also on Windows if you are using Cygwin.
Approach 1) I would just have a specific directory in which I have ONLY these files containing the ticker data and nothing else. I would then use the C readdir API to list all files in the directory and iterate over each one performing the data processing that you require. Which ticker the file applies to is determined only by the filename.
Pros: Easy to code
Cons: It really depends where the files are stored and where they come from.
Approach 2) Change the file format so the ticker files start with a magic code identifying that this is a ticker file, and a string containing the name. As before use readdir to iterate through all files in the folder and open each file, ensure that the magic number is set and read the ticker name from the file, and process the data as before
Pros: More flexible than before. Filename needn't reflect name of ticker
Cons: Harder to code, file format may be fixed.
but I'd really like to avoid typing out over a thousand file names into a text file. Is there a better way to approach this?
I have solved the exact same problem a while back, albeit for personal uses :)
What I did was to use the OS shell commands to generate a list of those files and redirected the output to a text file and had my program run through them.
On UNIX, there's the handy glob function:
glob_t results;
memset(&results, 0, sizeof(results));
glob("*.txt", 0, NULL, &results);
for (i = 0; i < results.gl_pathc; i++)
printf("%s\n", results.gl_pathv[i]);
globfree(&results);
On Linux or a related system, you could use the fts library. It's designed for traversing file hierarchies: man fts,
or even something as simple as readdir
If on Windows, you can use their Directory Management API's. More specifically, the FindFirstFile function, used with wildcards, in conjunction with FindNextFile
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.