| name | hive.terminal-tools-job-control |
| description | Use when launching anything that runs longer than a minute, anything that streams logs, anything you want to keep running while doing other work — or when terminal_exec auto-backgrounded on you and returned a job_id. Teaches the start→poll→wait pattern with terminal_job_logs offset bookkeeping, the `wait_until_exit=True` blocking-poll idiom, the truncated_bytes_dropped resumption signal, the merge_stderr decision, the SIGINT→SIGTERM→SIGKILL escalation ladder via terminal_job_manage, and the hard rule that jobs die when the terminal-tools server restarts. Read before calling terminal_job_start, or right after terminal_exec auto-backgrounded. |
| metadata | {"author":"hive","type":"preset-skill","version":"1.0"} |
Background job control
Background jobs are how you do things that take time without blocking your conversation. Three tools cover the surface: terminal_job_start, terminal_job_logs, terminal_job_manage.
When to use a job
- Builds, deploys, long tests
- Processes you want to monitor (streaming a log file, a dev server)
- Anything that auto-backgrounded from
terminal_exec (you have a job_id; pivot to this skill's idioms)
For one-shot work expected to finish quickly, terminal_exec is simpler. The auto-promotion mechanic in terminal_exec is your safety net — start with terminal_exec, take over with this skill if needed.
Lifecycle
terminal_job_start(command, ...)
→ { job_id, pid, started_at }
terminal_job_logs(job_id, since_offset=0, max_bytes=64000)
→ { data, offset, next_offset, status: "running"|"exited", exit_code, ... }
# Repeat with since_offset = previous next_offset until status == "exited"
# Or block once with wait_until_exit=True:
terminal_job_logs(job_id, since_offset=N, wait_until_exit=True, wait_timeout_sec=60)
→ blocks server-side until exit or timeout
After exit, the job is retained for inspection (terminal_job_manage(action="list")) until evicted by FIFO (50 most recent exits kept).
Offset bookkeeping — the only rule that matters
The job's output lives in a 4 MB ring buffer per stream. Each call to terminal_job_logs returns:
data — bytes between since_offset and next_offset
next_offset — pass this as since_offset on your next call
truncated_bytes_dropped — non-zero when your since_offset was older than the ring's floor (you fell behind)
Always carry next_offset forward. Don't replay from 0 — that's an offset reset, you'll see the same data twice and miss the part that fell off.
When truncated_bytes_dropped > 0, the buffer evicted N bytes between your last call and now. Treat it as a signal that the job is producing output faster than you're consuming. Either poll more often or accept the gap and read from next_offset going forward.
merge_stderr — interleaved or separate
merge_stderr=False → two streams, request "stdout" or "stderr" by name
merge_stderr=True → one stream ("merged"), order preserved
Pick merge_stderr=True when:
- The job's logs are designed to be read together (most servers, build tools)
- You don't need to distinguish "this was stderr"
Pick merge_stderr=False when:
- stderr is genuinely error-only and stdout is data
- You'll process them differently
Signal escalation
terminal_job_manage(action="signal_int", job_id=...) # graceful (Ctrl-C-equivalent)
terminal_job_manage(action="signal_term", job_id=...) # polite kill (SIGTERM)
terminal_job_manage(action="signal_kill", job_id=...) # forced kill (SIGKILL, uncatchable)
The idiom: signal_int → wait 2-5s → signal_term → wait 2-5s → signal_kill. Most well-behaved processes handle SIGINT (graceful) and SIGTERM (cleanup, then exit). SIGKILL bypasses cleanup — use only when the process is truly unresponsive.
After signaling, check exit with terminal_job_logs(job_id, wait_until_exit=True, wait_timeout_sec=2).
Stdin
terminal_job_manage(action="stdin", job_id=..., data="some input\n")
terminal_job_manage(action="close_stdin", job_id=...)
For tools that read stdin to EOF, close_stdin after writing flushes them. For interactive tools that read line-by-line, just write each line.
Take-over: when terminal_exec auto-backgrounds
When terminal_exec returned auto_backgrounded: true, job_id: <X>, the process is already in the JobManager with its output flowing into the ring buffer. Your transition is seamless:
# Already saw the start of output in terminal_exec's stdout/stderr.
# Pick up reading where the env left off — use the byte count of the
# initial stdout as your since_offset, OR just request tail output:
terminal_job_logs(job_id="job_xxx", tail=True, max_bytes=64000)
Or block until exit and grab everything:
terminal_job_logs(job_id="job_xxx", since_offset=0, wait_until_exit=True, wait_timeout_sec=120)
Hard rules
- Jobs die when the server restarts. The desktop runtime restarts terminal-tools when Hive restarts. There's no re-attach. If you need durability, use
nohup + terminal_exec to detach into the system's process tree and track the PID yourself.
- Server-wide hard cap on concurrent jobs (
TERMINAL_TOOLS_MAX_JOBS, default 32). Past the cap, terminal_job_start returns an error. Wait for jobs to exit or kill old ones.
- No cross-restart output. Output handles and ring buffers are in-memory only.
See references/signals.md for the full signal catalog.