Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

Disambiguating multiple formatted files when writing to standard output

Open
  • Is something wrong?
#994 0 comments 0 reactions 0 assignees View on GitHub

Maintainers usually reply within 1 day

Nobody has claimed this yet.

Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
38/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Stale
Tech stack
java
Domain
cli

Research direction

Start with the google-java-format CLI invocation shown in the issue, focusing on multi-file formatting sent to standard output. Determine a clear way to associate each formatted result with its source path, then verify the behavior with the four-file example and equivalent batched input.

Written by the indexing model from the issue text.

Description

When using google-java-format to format multiple files and print their formatted results to standard-out, it's unclear how I'm supposed to disambiguate between the results in the output. For performance reasons, I am running google-java-format against my codebase in batches of 100 files at a time, and for various other reasons, formatting in-place is not preferred.

For example, running this:

java -jar $HOME/bin/google-java-format --aosp path/to/file1.java path/to/file2.java path/to/file3.java path/to/file4.java

results in output like this:

/* my file 1 */

public class File1 {
    // ...
}
/* my file 2 */

public class File2 {
    // ...
}
/* my file 3 */

public class File3 {
    // ...
}
/* my file 4 */

public class File4 {
    // ...
}

This example is kind of contrived, but the main point is that the end of file1.java and the start of file2.java, and so on, are not delimited in a clear way. What can I do here to clearly associate the output for each formatted file with its source path?

Dominant language
Java
Stars
6.2k
Forks
936
Avg merge
6m
Merged PRs (30d)
3

Getting set up

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from google/google-java-format

All issues in google/google-java-format

Similar issues

More Java issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.