uutils/coreutils · error · io::Error

Is a directory

Error message

Is a directory

What it means

While validating a checksum file line, get_file_to_check opened the named path successfully but stat shows it is a directory, so no digest can be computed. The code prints an 'Is a directory' io error, counts it as a failed open, and returns LineCheckError::FileIsDirectory — the line is treated as a verification failure.

Solutions

1. Remove or skip directory entries from the checksum file — checksums apply to regular files only.
2. Generate the manifest correctly: find . -type f -exec sha256sum {} + > file.sha256
3. Run find with -type d filtering or exclude directories when creating/verifying the list.
4. Check the path in the checksum file relative to your cwd; cd to the manifest's root directory before `sha256sum -c`.

Example fix

# before: checksum file contains a directory line -> "Is a directory"
grep -v '/$' checksums.sha256 > checksums.files.sha256
# after: regenerate from files only
find . -type f -exec sha256sum {} + > checksums.sha256
sha256sum -c checksums.sha256

# Filter directory entries out of a checksum manifest before -c
awk '$1 !~ /^[0-9a-fA-F]{32,}$/ {next} {print}' checksums.sha256 > clean.sha256
# or generate correctly in the first place:
find . -type f -exec sha256sum {} + > checksums.sha256

// Node: skip directories listed in a manifest
const st = fs.statSync(line.path, { throwIfNoEntry: false });
if (!st || !st.isFile()) return; // skip dirs/missing entries

match compute_and_check_digest_from_file(...) {
  Err(LineCheckError::FileIsDirectory) => {
    eprintln!("skipping {}: it is a directory, not a file", path);
  }
  Err(e) => return Err(e),
  Ok(digest) => verify(digest),
}

When it happens

Trigger: Running `sha256sum -c` (or md5sum -c) where the checksum file lists a path that is actually a directory, e.g. a manually written checksum file or a generated one containing 'dir/' entries; also nested directories with a checksum file per directory (check mode) encountering directory names.

Common situations: Hand-maintained .sha256 files with directory names pasted in; tools generating manifest entries for directories by mistake; running checksum verification from the wrong working directory where the same name maps to a directory; with `--check` inside recursive setups.

Related errors

• mv-error-directory-not-empty
• realpath-invalid-empty-operand

AI-assisted analysis of uutils/coreutils@92995feca2 (2026-09-20). Data as JSON: /api/errors/f661ca636c1c0101. Report an issue: GitHub.

Appendix: source

Thrown at src/uucore/src/lib/features/checksum/validate.rs:570

                FileChecksumResult::CantOpen,
                opts.verbose,
            );
        };
        let print_error = |err: io::Error| {
            show!(err.map_err_context(|| {
                locale_aware_escape_name(filename, QuotingStyle::SHELL_ESCAPE)
                    // This is non destructive thanks to the escaping
                    .to_string_lossy()
                    .to_string()
            }));
        };
        match File::open(filename) {
            Ok(f) => {
                if f.metadata()
                    .map_err(|_| LineCheckError::CantOpenFile)?
                    .is_dir()
                {
                    print_error(io::Error::new(
                        io::ErrorKind::IsADirectory,
                        "Is a directory",
                    ));
                    // also regarded as a failed open
                    failed_open();
                    Err(LineCheckError::FileIsDirectory)
                } else {
                    Ok(Box::new(f))
                }
            }
            Err(err) => {
                if !opts.ignore_missing {
                    // yes, we have both stderr and stdout here
                    print_error(err);
                    failed_open();
                }
                // we could not open the file but we want to continue
                Err(LineCheckError::FileNotFound)

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