cut: add comments about handling multiple cutting mode args

This commit is contained in:
wolimst 2024-02-09 22:15:18 +09:00
parent cb0ce0e1cb
commit 0ac8606577

View file

@ -359,6 +359,9 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
let complement = matches.get_flag(options::COMPLEMENT);
// Only one, and only one of cutting mode arguments, i.e. `-b`, `-c`, `-f`,
// is expected. The number of those arguments is used for parsing a cutting
// mode and handling the error cases.
let mode_args_count = [
matches.indices_of(options::BYTES),
matches.indices_of(options::CHARACTERS),
@ -521,6 +524,13 @@ pub fn uu_app() -> Command {
.about(ABOUT)
.after_help(AFTER_HELP)
.infer_long_args(true)
// While `args_override_self(true)` for some arguments, such as `-d`
// and `--output-delimiter`, is consistent to the behavior of GNU cut,
// arguments related to cutting mode, i.e. `-b`, `-c`, `-f`, should
// cause an error when there is more than one of them, as described in
// the manual of GNU cut: "Use one, and only one of -b, -c or -f".
// `ArgAction::Append` is used on `-b`, `-c`, `-f` arguments, so that
// the occurrences of those could be counted and be handled accordingly.
.args_override_self(true)
.arg(
Arg::new(options::BYTES)