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tail: Handle missing/dir paths via metadata() #10220

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8763bed
tail: handle missing/dir paths via metadata()
Xylphy Jan 13, 2026
23e6d96
tail: add regression test for EACCES metadata errors
Xylphy Jan 13, 2026
0ba66d4
Merge branch 'main' of github.com:uutils/coreutils into tail-metadata…
Xylphy Jan 18, 2026
fdf95f9
tail: ignored words
Xylphy Jan 18, 2026
050e9d0
tail: extract success-path open handling into helper
Xylphy Jan 19, 2026
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191 changes: 119 additions & 72 deletions src/uu/tail/src/tail.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -120,92 +120,139 @@ fn uu_tail(settings: &Settings) -> UResult<()> {
Ok(())
}

fn tail_file(
fn tail_opened_file(
mut file: File,
settings: &Settings,
header_printer: &mut HeaderPrinter,
input: &Input,
path: &Path,
observer: &mut Observer,
offset: u64,
) -> UResult<()> {
if !path.exists() {
set_exit_code(1);
show_error!(
"{}",
translate!("tail-error-cannot-open-no-such-file", "file" => input.display_name.clone(), "error" => translate!("tail-no-such-file-or-directory"))
);
let st = file.metadata()?;
let blksize_limit = uucore::fs::sane_blksize::sane_blksize_from_metadata(&st);
header_printer.print_input(input);

let mut reader;
if !settings.presume_input_pipe
&& file.is_seekable(if input.is_stdin() { offset } else { 0 })
&& (!st.is_file() || st.len() > blksize_limit)
{
bounded_tail(&mut file, settings);
reader = BufReader::new(file);
} else {
reader = BufReader::new(file);
unbounded_tail(&mut reader, settings)?;
}

if input.is_tailable() {
observer.add_path(
path,
input.display_name.as_str(),
Some(Box::new(reader)),
true,
)?;
} else {
observer.add_bad_path(path, input.display_name.as_str(), false)?;
} else if path.is_dir() {
set_exit_code(1);

header_printer.print_input(input);
let err_msg = translate!("tail-is-a-directory");

show_error!(
"{}",
translate!("tail-error-reading-file", "file" => input.display_name.clone(), "error" => err_msg)
);
if settings.follow.is_some() {
let msg = if settings.retry {
""
} else {
&translate!("tail-giving-up-on-this-name")
};
}

Ok(())
}

fn tail_file(
settings: &Settings,
header_printer: &mut HeaderPrinter,
input: &Input,
path: &Path,
observer: &mut Observer,
offset: u64,
) -> UResult<()> {
match path.metadata() {
Ok(md) if md.is_dir() => {
set_exit_code(1);

header_printer.print_input(input);
let err_msg = translate!("tail-is-a-directory");

show_error!(
"{}",
translate!("tail-error-cannot-follow-file-type", "file" => input.display_name.clone(), "msg" => msg)
translate!(
"tail-error-reading-file",
"file" => input.display_name.clone(),
"error" => err_msg
)
);
}
if !observer.follow_name_retry() {
// skip directory if not retry
return Ok(());
}
observer.add_bad_path(path, input.display_name.as_str(), false)?;
} else {
#[cfg(unix)]
let open_result = open_file(path, settings.pid != 0);
#[cfg(not(unix))]
let open_result = File::open(path);

match open_result {
Ok(mut file) => {
let st = file.metadata()?;
let blksize_limit = uucore::fs::sane_blksize::sane_blksize_from_metadata(&st);
header_printer.print_input(input);
let mut reader;
if !settings.presume_input_pipe
&& file.is_seekable(if input.is_stdin() { offset } else { 0 })
&& (!st.is_file() || st.len() > blksize_limit)
{
bounded_tail(&mut file, settings);
reader = BufReader::new(file);
} else {
reader = BufReader::new(file);
unbounded_tail(&mut reader, settings)?;
}
if input.is_tailable() {
observer.add_path(
path,
input.display_name.as_str(),
Some(Box::new(reader)),
true,
)?;
if settings.follow.is_some() {
let msg = if settings.retry {
""
} else {
observer.add_bad_path(path, input.display_name.as_str(), false)?;
}
}
Err(e) if e.kind() == ErrorKind::PermissionDenied => {
observer.add_bad_path(path, input.display_name.as_str(), false)?;
show!(e.map_err_context(|| {
translate!("tail-error-cannot-open-for-reading", "file" => input.display_name.clone())
}));
&translate!("tail-giving-up-on-this-name")
};
show_error!(
"{}",
translate!(
"tail-error-cannot-follow-file-type",
"file" => input.display_name.clone(),
"msg" => msg
)
);
}
Err(e) => {
observer.add_bad_path(path, input.display_name.as_str(), false)?;
return Err(e.map_err_context(|| {
translate!("tail-error-cannot-open-for-reading", "file" => input.display_name.clone())
}));
if !observer.follow_name_retry() {
return Ok(());
}
observer.add_bad_path(path, input.display_name.as_str(), false)?;
return Ok(());
}
Err(e) if e.kind() == ErrorKind::NotFound => {
set_exit_code(1);
show_error!(
"{}",
translate!(
"tail-error-cannot-open-no-such-file",
"file" => input.display_name.clone(),
"error" => translate!("tail-no-such-file-or-directory")
)
);
observer.add_bad_path(path, input.display_name.as_str(), false)?;
return Ok(());
}
_ => {}
}

#[cfg(unix)]
let open_result = open_file(path, settings.pid != 0);
#[cfg(not(unix))]
let open_result = File::open(path);

match open_result {
Ok(file) => {
tail_opened_file(
file,
settings,
header_printer,
input,
path,
observer,
offset,
)?;
}
Err(e) if e.kind() == ErrorKind::PermissionDenied => {
observer.add_bad_path(path, input.display_name.as_str(), false)?;
show!(e.map_err_context(|| {
translate!(
"tail-error-cannot-open-for-reading",
"file" => input.display_name.clone()
)
}));
}
Err(e) => {
observer.add_bad_path(path, input.display_name.as_str(), false)?;
return Err(e.map_err_context(|| {
translate!(
"tail-error-cannot-open-for-reading",
"file" => input.display_name.clone()
)
}));
}
}

Expand Down
53 changes: 52 additions & 1 deletion tests/by-util/test_tail.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@
// spell-checker:ignore (ToDO) abcdefghijklmnopqrstuvwxyz efghijklmnopqrstuvwxyz vwxyz emptyfile file siette ocho nueve diez MULT
// spell-checker:ignore (libs) kqueue
// spell-checker:ignore (jargon) tailable untailable datasame runneradmin tmpi
// spell-checker:ignore (cmd) taskkill
// spell-checker:ignore (cmd) taskkill noaccess topsecret
#![allow(
clippy::unicode_not_nfc,
clippy::cast_lossless,
Expand Down Expand Up @@ -296,6 +296,57 @@ fn test_permission_denied_multiple() {
.stdout_is("==> file1 <==\n\n==> file2 <==\n");
}

// TODO: Add similar test for windows
#[test]
#[cfg(all(unix, not(target_os = "android")))]
fn test_permission_denied_from_metadata_error() {
use std::fs;
use std::os::unix::fs::PermissionsExt;

let ts = TestScenario::new(util_name!());
let at = &ts.fixtures;

at.mkdir("noaccess");
at.write("noaccess/secret", "topsecret\n");

// Make the directory non-searchable so path lookup fails with EACCES.
fs::set_permissions(at.plus("noaccess"), fs::Permissions::from_mode(0o000)).unwrap();

ts.ucmd()
.arg("noaccess/secret")
.fails_with_code(1)
.no_stdout()
.stderr_is("tail: cannot open 'noaccess/secret' for reading: Permission denied\n");

// Restore permissions so the test harness can clean up the temp directory.
fs::set_permissions(at.plus("noaccess"), fs::Permissions::from_mode(0o700)).unwrap();
}

// Same as above, but ensure we keep processing subsequent files.
// TODO: Add similar test for windows
#[test]
#[cfg(all(unix, not(target_os = "android")))]
fn test_permission_denied_from_metadata_error_multiple() {
use std::fs;
use std::os::unix::fs::PermissionsExt;

let (at, mut ucmd) = at_and_ucmd!();

at.touch("file1");
at.touch("file2");

at.mkdir("noaccess");
at.write("noaccess/secret", "topsecret\n");
fs::set_permissions(at.plus("noaccess"), fs::Permissions::from_mode(0o000)).unwrap();

ucmd.args(&["file1", "noaccess/secret", "file2"])
.fails_with_code(1)
.stdout_is("==> file1 <==\n\n==> file2 <==\n")
.stderr_is("tail: cannot open 'noaccess/secret' for reading: Permission denied\n");

fs::set_permissions(at.plus("noaccess"), fs::Permissions::from_mode(0o700)).unwrap();
}

#[test]
fn test_follow_redirect_stdin_name_retry() {
// $ touch f && tail -F - < f
Expand Down
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