fix: handle EAGAIN error when reading stdin in hook scripts#189
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chelseachen007 wants to merge 1 commit intoopenai:mainfrom
Open
fix: handle EAGAIN error when reading stdin in hook scripts#189chelseachen007 wants to merge 1 commit intoopenai:mainfrom
chelseachen007 wants to merge 1 commit intoopenai:mainfrom
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When Claude Code runs hook scripts, stdin (fd 0) may be set to
non-blocking mode (O_NONBLOCK). If no data is available,
`fs.readFileSync(0, "utf8")` throws EAGAIN ("resource temporarily
unavailable"), causing the hook to crash instead of gracefully
handling the empty input.
This wraps the readFileSync(0) calls in readHookInput() with a
try-catch that treats EAGAIN/EWOULDBLOCK the same as empty input
(returns {}), matching the existing behavior for empty stdin.
Affected scripts:
- stop-review-gate-hook.mjs
- session-lifecycle-hook.mjs
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Summary
EAGAIN("resource temporarily unavailable") crash inreadHookInput()when stdin (fd 0) is in non-blocking mode and no data is availablefs.readFileSync(0, "utf8")with try-catch in bothstop-review-gate-hook.mjsandsession-lifecycle-hook.mjs, treatingEAGAIN/EWOULDBLOCKthe same as empty input (returns{})Problem
When Claude Code runs hook scripts, stdin may be set to non-blocking mode (
O_NONBLOCK). If no data is available on fd 0,fs.readFileSync(0, "utf8")throws:This causes the stop hook to crash instead of gracefully proceeding with no input.
Test plan
EAGAIN/EWOULDBLOCK, all other errors re-throw{}(same as before for empty string)🤖 Generated with Claude Code