can1357/oh-my-pi · error · WcError

{path}:{idx}: invalid zero-length file name

Error message

{path}:{idx}: invalid zero-length file name

What it means

WcError::ZeroLengthFileNameCtx is the context-carrying form of the zero-length file name error: `{path}:{idx}: invalid zero-length file name` names the source of the list (path, or stdin) and the 0-based record index, so malformed --files0-from input can be located precisely. It wraps the same condition as ZeroLengthFileName.

Source

Thrown at crates/pi-builtins/src/wc.rs:791

impl TotalWhen {
	fn is_total_row_visible(self, num_inputs: usize) -> bool {
		match self {
			Self::Auto => num_inputs > 1,
			Self::Always | Self::Only => true,
			Self::Never => false,
		}
	}
}

#[derive(Debug, Error)]
enum WcError {
	#[error("extra operand {}\nfile operands cannot be combined with --files0-from", extra.quote())]
	FilesDisabled { extra: Cow<'static, OsStr> },
	#[error("when reading file names from standard input, no file name of '-' allowed")]
	StdinReprNotAllowed,
	#[error("invalid zero-length file name")]
	ZeroLengthFileName,
	#[error("{path}:{idx}: invalid zero-length file name")]
	ZeroLengthFileNameCtx { path: Cow<'static, str>, idx: usize },
	#[error("{context}: {source}")]
	Io {
		context: String,
		#[source]
		source:  io::Error,
	},
}

impl WcError {
	fn zero_len(ctx: Option<(&Input, usize)>) -> Self {
		match ctx {
			Some((input, idx)) => {
				let path = match input {
					Input::Stdin(_) => STDIN_REPR.into(),
					Input::Path(path) => escape_name_wrapper(path.as_os_str()).into(),
				};
				Self::ZeroLengthFileNameCtx { path, idx }

View on GitHub (pinned to 9690622007)

Solutions

1. Open the list file at the record index reported in the message and remove the empty entry
2. Fix the generating command to skip empty inputs before emitting NUL terminators
3. Validate the list: `tr '\0' '\n' < list | grep -n '^$'` to find all empty records
4. Regenerate the list with `find ... -print0` which never emits empty names

Example fix

// message: list.txt:42: invalid zero-length file name
// after: inspect and rebuild the list
tr '\0' '\n' < list.txt | sed '42d' | tr '\n' '\0' > list.fixed
wc --files0-from=list.fixed

fn find_empty_records(bytes: &[u8]) -> Vec<usize> {
    bytes.split(|&b| b == 0)
        .enumerate()
        .filter(|(_, s)| s.is_empty())
        .map(|(i, _)| i)
        .collect()
}
// if !find_empty_records(&list).is_empty() { fix the list before invoking wc }

When it happens

Trigger: Reading file names from a --files0-from file (or stdin) and hitting an empty record at position idx — adjacent NULs in the named list file, or an empty record streamed on stdin.

Common situations: Large generated lists where one producer bug inserted an empty entry; concatenated list files with stray NULs at joins; debugging which record in a huge list is malformed.

Related errors

• invalid zero-length file name
• {}:{}: invalid zero-length file name
• when reading file names from standard input, no file name of
• err.to_string() (timestamp parse error)
• duration is too large: {value}

AI-assisted analysis of can1357/oh-my-pi@9690622007 (2026-08-31). Data as JSON: /api/errors/fcc41c4bc507b237. Report an issue: GitHub.