When a stream is opened for both reading and writing, you are not allowed to directly switch between reading and writing. §7.21.5.3 ¶7 of the ISO C11 standard states the following: When a file is opened with update mode (‘+’ as the second or third character in the above list of mode argument values), both … Read more
Looks like the answer is no: http://download.oracle.com/javase/1.4.2/docs/api/java/io/FileOutputStream.html http://docs.oracle.com/javase/7/docs/api/index.html?java/io/FileOutputStream.html There are no public methods that return the File or String used in construction of the stream. EDIT: The same holds for FileInputStream.
I want to add an example: #include <unistd.h> #include <fcntl.h> #include <stdio.h> int main(int argc, char const *argv[]) { char buf[20]; fcntl(0, F_SETFL, fcntl(0, F_GETFL) | O_NONBLOCK); sleep(4); int numRead = read(0, buf, 4); if (numRead > 0) { printf(“You said: %s”, buf); } } When you run this program you have 4 seconds to … Read more
1) I am sure there is no difference speedwise, both use FileInputStream internally and buffering 2) You can take measurements and see for yourself 3) Though there’s no performance benefits I like the 1.7 approach try (BufferedReader br = Files.newBufferedReader(Paths.get(“test.txt”), StandardCharsets.UTF_8)) { for (String line = null; (line = br.readLine()) != null;) { // } … Read more
Windows file caching is very effective, especially if you are using Vista or later. TFileStream is a loose wrapper around the Windows ReadFile() and WriteFile() API functions and for many use cases the only thing faster is a memory mapped file. However, there is one common scenario where TFileStream becomes a performance bottleneck. That is … Read more
There are no universal standards, but there are reasons to prefer one or another. My preferred form is this: open( my $input_fh, “<“, $input_file ) || die “Can’t open $input_file: $!”; The reasons are: You report errors immediately. (Replace “die” with “warn” if that’s what you want.) Your filehandle is now reference-counted, so once you’re … Read more
In bash, read can do it: read -n1 ans
It could well be a permission problem. From the documentation: The Exists method returns false if any error occurs while trying to determine if the specified file exists. This can occur in situations that raise exceptions such as passing a file name with invalid characters or too many characters, a failing or missing disk, or … Read more
I advise you to go with Scanner instead of DataInputStream. Scanner is specifically designed for this purpose and introduced in Java 5. See the following links to know how to use Scanner. Java Documentation Java Tutorial Example Scanner s = new Scanner(System.in); System.out.println(s.nextInt()); System.out.println(s.nextInt()); System.out.println(s.next()); System.out.println(s.next());
do notation in Haskell desugars in a pretty simple way. do x <- foo e1 e2 … turns into foo >>= \x -> do e1 e2 and do x e1 e2 … into x >> do e1 e2 …. This means you can really write any monadic computation with >>= and return. The only reason … Read more