tee is supposed to exit when there is nothing left to write to. For
finite inputs, it can be hard to determine whether this functions
correctly, but for tee of infinite streams, it is very important to
exit when there is nothing more to write to.
This is part of fixing the tee tests. 'yes' is used by the GNU test
suite to identify what the SIGPIPE exit code is on the target
platform. By trapping SIGPIPE, it creates a requirement that other
utilities also trap SIGPIPE (and exit 0 after SIGPIPE). This is
sometimes at odds with their desired behaviour.
When the monitored process exits, the GNU version of timeout will
preserve its exit status, including the signal state.
This is a partial fix for timeout to enable the tee tests to pass. It
removes the default Rust trap for SIGPIPE, and kill itself with the
same signal as its child exited with to preserve the signal state.
This has the following behaviours. On Unix:
- The default is to exit on pipe errors, and warn on other errors.
- "--output-error=warn" means to warn on all errors
- "--output-error", "--output-error=warn-nopipe" and "-p" all mean
that pipe errors are suppressed, all other errors warn.
- "--output-error=exit" means to warn and exit on all errors.
- "--output-error=exit-nopipe" means to suppress pipe errors, and to
warn and exit on all other errors.
On non-Unix platforms, all pipe behaviours are ignored, so the default
is effectively "--output-error=warn" and "warn-nopipe" is identical.
The only meaningful option is "--output-error=exit" which is identical
to "--output-error=exit-nopipe" on these platforms.
Note that warnings give a non-zero exit code, but do not halt writing
to non-erroring targets.
Add a `uucore::fs::is_symlink()` function that takes in a
`std::path::Path` and decides whether the given path is a symbolic
link. This is essentially a backport of the `Path::is_symlink()`
function that appears in Rust version 1.58.0. This commit also
replaces some now-duplicate code in `chmod`, `cp`, `ln`, and `rmdir`
that checks whether a path is a symbolic link with a call to
`is_symlink()`.
Technically, this commit slightly changes the behavior of
`cp`. Previously, there was a line of code like this
if fs::symlink_metadata(&source)?.file_type().is_symlink() {
where the `?` operator propagates an error from `symlink_metadata()`
to the caller. Now the line of code is
if is_symlink(source) {
in which any error from `symlink_metadata()` has been converted to
just be a `false` value. I believe this is a satisfactory tradeoff to
make, since an error in accessing the file will likely cause an error
later in the same code path.
This change will extract a utility already present in ls to uucore.
This utility is used by dir and vdir too, which are adjusted to
look it up in uucode. No further changes to ls, dir or dirv intended.
The change here largely fiddles with the output of uu_wc to match
that of GNU wc. This is the case to the extent to make unit tests
pass, however, there are differences remaining. One specific
difference I did not tackle is that GNU wc will not align the
output columns (compute_number_width() -> 1) in the specific case
of the input for --files0-from=- being a named pipe, not real stdin.
This difference can be triggered using the following two invocations.
- wc --files0-from=- < files0 # use a named pipe, GNU does align
- cat files0- | wc --files0-from=- # use real stdin, GNU does not
align.
