Get content of a file in Java

Question

I want to get the version of Linux using Java code. In different Linux distributions I have file with diffrent name.

/etc/*-release

How I can get every file content which ends with -release?

The latest version != current version. Do you like to know the current running linux version? — Grim, Apr 28 '14 at 11:52

score 6 · Accepted Answer · answered Apr 28 '14 at 11:31

6

You can use File.listFiles(FilenameFilter)

    File f = new File("/etc/");
    File[] allReleaseFiles = f.listFiles(new FilenameFilter() {

        @Override
        public boolean accept(File dir, String name) {
            return name.endsWith("-release");
        }
    });

answered Apr 28 '14 at 11:31

sanbhat

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Is this the best solution? Can I optimize this code? – Peter Penzov Apr 28 '14 at 11:33
What do you want to optimize here? The code is short, precise and readable. You apply a filter to a list of files, the resulting ``File[]`` contains exactly the files you ask for. – f1sh Apr 28 '14 at 11:35
@PeterPenzov Did you try it out? Was it too slow? Don't optimize too soon – Absurd-Mind Apr 28 '14 at 11:35
@PeterPenzov This is just a convenience given by API. If you want to do it yourself, you can list all files within `etc` folder and add only those which ends with `release`, in a `for loop`. I don't think you can further optimize this. – sanbhat Apr 28 '14 at 11:36

score 2 · Answer 2 · answered Apr 28 '14 at 11:32

2

Use Java java.io.File#listFiles and then simply iterate over the array that it returns to open the files.

answered Apr 28 '14 at 11:32

Loic Duros

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score 1 · Answer 3 · answered Apr 28 '14 at 11:53

1

System.getProperty("os.version")

answered Apr 28 '14 at 11:53

Grim

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score 0 · Answer 4 · edited May 23 '17 at 11:59

0

You can get files by getting output after executing ls -d /etc/*-release.

And then work with them via Java File.

See also:

edited May 23 '17 at 11:59

Community

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answered Apr 28 '14 at 11:39

Rong Nguyen

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I think, it's incorrect to run platform-dependent commands instead of using language abilities. – Dmitry Ginzburg Apr 28 '14 at 14:30

score 0 · Answer 5 · answered Apr 28 '14 at 14:29

0

Surely, you should use nio nowadays for this type of action:

Path dir = Paths.get("/etc");
for (Path file : Files.newDirectoryStream(dir, "*-release"))
    System.out.println (new String(Files.readAllBytes(file), "UTF-8"));

answered Apr 28 '14 at 14:29

Dmitry Ginzburg

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Get content of a file in Java

5 Answers5