Replace all occurrences of character in file

Question

Is there a quick way to replace all occurrences of a given character in a file (the whole file at once) for another?

I wonder if this could be done in a global way or something, without reading it line by line.

in my specific case, I want to replace pipes (|) for commas (,).

Does this have to be done in Java? It would be trivial to do `sed -i 's/|/,/g' filename`. — SimonC, Apr 19 '13 at 19:56

score 2 · Accepted Answer · edited May 23 '17 at 12:12

2

Simply retrieve the text from the file and then use string.replaceAll("\\|", ",");

Here is an example using the code from erickson's answer:

private static String readFile(String path) throws IOException {
  FileInputStream stream = new FileInputStream(new File(path));
  try {
    FileChannel fc = stream.getChannel();
    MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
    /* Instead of using default, pass in a decoder. */
    return Charset.defaultCharset().decode(bb).toString();
  }
  finally {
    stream.close();
  }
}

You can use it like this:

String replacedTxt = readFile(path).replaceAll("\\|", ",");

edited May 23 '17 at 12:12

Community

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answered Apr 19 '13 at 19:55

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You need to escape the pipe as the string is a regex: `replaceAll("\|", ",")`. – SimonC Apr 19 '13 at 19:58
@SimonC I think it will need `"\\|"` in java other wise it wont compile. – Smit Apr 19 '13 at 20:00
1

Don't forget you have to write it back to the file. – Sotirios Delimanolis Apr 19 '13 at 20:13

Replace all occurrences of character in file

1 Answers1