dor send --stdin interprets backslash escapes in piped bytes #355

dor send --stdin interprets backslash escapes in piped bytes, corrupting the documented use case

dor send --stdin reads standard input and forwards it as a text input:

if (flags.stdin === true) {
  if (!readStdin) return { ok: false, message: 'stdin is not available' };
  return { ok: true, value: [{ kind: 'text', text: await readStdin() }] };
}

(send.ts:183-186)

Text inputs then run through interpretTextEscapes unless --raw is set:

input += raw ? item.text : interpretTextEscapes(item.text);

(send.ts:227-228, converting \n \r \t \\ at send.ts:238-253)

Why this is a footgun for --stdin

The flagship stdin example in the help is:

cat script.sh | dor send surface:3 --stdin

(send.ts:115)

Bytes arriving on stdin are already literal — they are not a shell-authored string where a two-character \t stands in for a tab. Shell scripts routinely contain literal backslash sequences (printf 'a\tb', sed 's/\n/ /', grep -P '\d', Windows paths with \\). Piping such a file through --stdin silently rewrites every \n/\r/\t/\\, so the text typed into the target terminal is not the file's contents.

Repro: printf 'printf "a\\tb\\n"\n' | dor send surface:3 --stdin types a real TAB and newline into the middle of the line instead of the literal \t/\n the script source contains.

The escape interpretation is desirable for --text "echo hi\nthere" (a human types escapes on the command line), but for --stdin the input is already-real bytes.

Design question (why an issue, not a drive-by PR)

The current behavior is consistent with the documented contract — the help says "Text input interprets backslash escapes … unless --raw is set" (send.ts:97), and --stdin is documented as text input — so flipping the default is a contract change that needs a maintainer call. Options:

1. Make --stdin raw by default — treat piped bytes as literal; keep --text interpreting escapes. Most aligned with the cat script.sh | … example. Would need an opt-in flag if anyone wants escape interpretation on stdin.
2. Keep current behavior, document it — call out at the --stdin help that it interprets escapes and that --raw is needed for literal file contents.

I lean toward option 1, but it changes documented behavior, so I'm leaving the call to a maintainer. Happy to open the PR (including a regression test that pipes a script containing \t and asserts the bytes are preserved) once a direction is chosen.

_{Surfaced by the nightly code-quality survey.}