The answer to this question is both database dependent and implementation dependent. Here are some examples of how data can be stored: As a single file per database. (This is the default for SQL Server.) Using a separate file system manager, which could be the operating system. (MySQL has several options, with names like InnoDB.) … Read more
I also wish Xcode automatically kept itself and the file system in sync. So much so, that I spent an hour doing so manually for a project called acani-iphone on GitHub. Basically, I just moved some of the files around using Finder, creating new folders as I pleased. Then, I switched back to Xcode and … Read more
check also GlusterFS Edit (Aug-2012): Ceph is finally getting ready. Recently the authors formed Inktank, an independent company to sell commercial support for it. According to some presentaions, the mountable POSIX-compliant filesystem is the uppermost layer and not really tested yet, but the lower layers are being used in production for some time now. The … Read more
distutils.dir_util.copy_tree does what you want. Copy an entire directory tree src to a new location dst. Both src and dst must be directory names. If src is not a directory, raise DistutilsFileError. If dst does not exist, it is created with mkpath(). The end result of the copy is that every file in src is … Read more
At least on Windows 7, it seems that attempting to open a volume handle without FILE_SHARE_WRITE sharing permissions causes the file system cache to be invalidated, even if the creation fails. Thus I made a program that simply calls CreateFile to this end. Download the program* from its Base64 version here: <!– Click “Run Snippet”, … Read more
Say you have a file with many empty bytes \x00. These many empty bytes \x00 are called holes. Storing empty bytes is just not efficient, we know there are many of them in the file, so why store them on the storage device? We could instead store metadata describing those zeros. When a process reads … Read more
A GUID would be extremely fast, since it’s implementation guarantees Windows can generate at least 16,384 GUIDS in a 100-nanosecond timespan. (As others pointed out, the spec doesn’t guarantee, only allows for. However, GUID generation is really, really fast. Really.) The likelihood of collision on any filesystem anywhere on any network is very low. It’s … Read more
Check if the first line of file is empty: BufferedReader br = new BufferedReader(new FileReader(“path_to_some_file”)); if (br.readLine() == null) { System.out.println(“No errors, and file empty”); }
In new versions of boost (starting in 1.60), you can use boost::filesystem::relative. (See the documentation here.) #include <boost/filesystem.hpp> #include <iostream> namespace fs = boost::filesystem; int main() { fs::path parentPath(“/home/user1/”); fs::path childPath(“/home/user1/Downloads/Books”); fs::path relativePath = fs::relative(childPath, parentPath); std::cout << relativePath << std::endl; }
There is a helper library for looking up MIME types: Mime var mime = require(‘mime’); mime.getType(‘/path/to/file.txt’); // => ‘text/plain’ But it still uses the extension for lookup though.