fix(terminal): use stty -F/-f to read tty size in detached spawn#377
Merged
Conversation
The TTY-width probe walked ancestor processes to find a controlling
PTY and ran `stty size < /dev/${tty}` to read its dimensions. That
form fails with ENOTTY on Linux when the calling process has no
controlling terminal — which is now the case under Claude Code
>= 2.1.139, whose changelog reads "hooks now run without terminal
access". The statusLine spawn is hardened the same way. Probe falls
back to `tput cols` (= 80), flexMode "full-minus-40" collapses to
40 columns, and the statusline truncates regardless of the real
terminal width.
GNU coreutils `stty -F <path>` and BSD `stty -f <path>` open the
device themselves (with O_NOCTTY semantics) and succeed regardless
of controlling-tty status. Try `-F` then `-f` then the historical
redirect form so we keep working on every stty variant.
Verified: on a Linux+ptyxis spawn under Claude Code 2.1.140 the probe
goes from returning null to returning the real width (159 cols here)
without restarting the session.
Owner
|
Thanks, I'll publish this in the next release |
sirmalloc
added a commit
that referenced
this pull request
May 17, 2026
…380) * feat(terminal): honor CCSTATUSLINE_WIDTH env var to override probe Provide an explicit width override so users can bypass the TTY probe entirely when both ancestor-walk and `tput cols` fall through. This is the fallback case the existing probe cannot solve on its own: Claude Code >= 2.1.139 spawns statusline/hooks without terminal access, and in some configurations (IDE integrations, nested shells, certain agent-mode spawn paths) no ancestor process owns a TTY either. The ancestor walk fails, `tput cols` returns 80, and the multi-line layout truncates regardless of the actual iTerm2/terminal width. PR #377 (`stty -F`/`stty -f`) covers the case where an ancestor does hold a TTY but the legacy `< /dev/tty` form errors with ENOTTY. This patch is complementary -- it handles the case where the ancestor walk finds no TTY at all -- and gives users a knob today while upstream work on passing `terminalWidth` via stdin JSON (#308) lands. Change ------ `src/utils/terminal.ts` -- `probeTerminalWidth` now reads `CCSTATUSLINE_WIDTH` before any platform check or probe. A valid positive integer short-circuits with that value; anything else (missing, empty, non-numeric, zero, negative) falls through to the existing probe logic. Usage ----- Set the env var on the statusLine command in `~/.claude/settings.json`: ```json "statusLine": { "type": "command", "command": "CCSTATUSLINE_WIDTH=200 ccstatusline" } ``` Tests ----- Four new cases in `src/utils/__tests__/terminal.test.ts`: - override short-circuits probing entirely - non-positive override (`0`) falls back to probing - non-numeric override falls back to probing - override applies on Windows where probing is otherwise disabled `bunx vitest run src/utils/__tests__/terminal.test.ts` -> 12/12 pass. Full-suite delta vs `main`: 4 new passing tests, zero new failures (the pre-existing 105 env-specific failures in other suites are unchanged on both branches). `bun run lint` -> clean. * docs: document terminal width override --------- Co-authored-by: Matthew Breedlove <sirmalloc@gmail.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Fixes the TTY-width probe under Claude Code ≥ 2.1.139, which spawns the statusline without a controlling terminal:
The existing
stty size < /dev/${tty}form fails withENOTTYin that context.Closes #376.
Change
src/utils/terminal.ts—getWidthForTTYnow tries three variants in order; first positive integer wins:stty -F <path> size(GNU coreutils, Linux)stty -f <path> size(BSD, macOS)stty size < <path>(legacy fallback)Test plan
-Ferrors,-fsucceeds)