* tr: Fix regression causing read error with sockets
The test used for determining if a file descriptor
tested with fstat points to a directory is traditionally
done by using the S_IFMT mask[^1][^2], e.g.:
#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
In Rust, this translates to 'm & libc::S_IFMT == libc::S_IFDIR'.
is_stdin_directory() uses 'has!(mode, S_IFDIR)', which is
**not** equivalent and causes non-directory sockets to be
incorrectly recognized as directories. This causes uu-tr
to break when used with all sockets created with socketpair,
including ksh93 pipes[^3]. Below is an example Rust program
demonstrating why the current check is bogus:
fn main() {
use nix::sys::socket::{socketpair, SockFlag, AddressFamily, SockType};
use nix::sys::stat::fstat;
use libc::{S_IFDIR, S_IFMT, mode_t};
let (_fd1, fd2) = socketpair(AddressFamily::Unix, SockType::Stream, None, SockFlag::empty()).unwrap();
let mode = fstat(&fd2).unwrap().st_mode as mode_t;
if mode & S_IFMT == S_IFDIR { // Equivalent to S_ISDIR()
println!("Not reached"); // Not a dir, so unreachable
}
if mode & S_IFDIR == S_IFDIR { // Bogus check for S_IFDIR
println!("BAD");
}
}
- is_stdin_directory(): Fix the regression introduced in 3e4221a4
by replacing the bogus check with one equivalent to S_ISDIR().
- test_tr.rs: Add a regression test for this bug.
[^1]: https://sourceware.org/git/?p=glibc.git;a=blob;f=io/sys/stat.h;h=4bea9e9a#l123
[^2]: https://git.musl-libc.org/cgit/musl/tree/include/sys/stat.h?id=047a1639#n51
[^3]: https://github.com/ksh93/ksh/blob/cc5e0692/src/cmd/ksh93/sh/io.c#L98-L102
Fixes https://github.com/uutils/coreutils/issues/7658
* Add comment explaining rationale
Also fix cargo clippy lint.
(In case it isn't obvious, I'm fairly new to Rust)
* Fix more lint
Specifically:
- check_against_gnu_tr_tests_e: Yes, the test is about octal interpretation.
- check_against_gnu_tr_tests_ross_0a: Yes, the [Y*] generates multiple Y's, which causes conflicting replacements, which is why the operation is rejected.
- check_against_gnu_tr_tests_ross_0b: Same, plus a newline character was accidentally forgotten.
- check_against_gnu_tr_tests_fowler_1: Apparently the problem was fixed at some point.
Sylvestre LedruandGitHub
can1357andSylvestre Ledru
AnthonyandGitHub
David CARLIERandGitHub
Johnothan KingandGitHub
yuankunzhang
Dorian Peron
Jan Verbeek
Daniel Hofstetter
Dorian PeronandDorian Peron
Peng ZijunandGitHub
Andrew Liebenow
Ben Wiederhake