tac: -r regex flavor incompatibility

[sylvestre]

Component

tac

Description

Regex::new(separator) is not compatible with \|, example here https://www.gnu.org/software/coreutils/manual/html_node/tac-invocation.html

    let maybe_pattern = if regex {
        match regex::bytes::Regex::new(separator) {
            Ok(p) => Some(p),
            Err(e) => return Err(TacError::InvalidRegex(e).into()),
        }
    } else {
        None
    };

Test / Reproduction Steps

core_sbx$ echo abc > t
core_sbx$ tac -r -s 'x\|[^x]' t

cbacore_sbx$ ../target/release/tac -r -s 'x\|[^x]' t
abc

Impact

Scripts relying on GNU coreutils documentation and examples will get incorrect output without error.

[cakebaker]

Fixed by #10416