diff --git a/docs/reference/configuration/post-scripts.md b/docs/reference/configuration/post-scripts.md
index 9eb043f7..ca4c1980 100644
--- a/docs/reference/configuration/post-scripts.md
+++ b/docs/reference/configuration/post-scripts.md
@@ -25,6 +25,7 @@ is the same as `{command: "...", event: success, mode: file}`.
| `command` | required | The command to run, with `{variable}` placeholders |
| `event` | `success` | `success` when a file was written, `failure` when the download failed |
| `mode` | `file` | `file`, `season`, or `run`. See [Modes](#modes) |
+| `wait` | `false` | `true` makes unshackle wait for the script to exit before carrying on. See [Waiting for a script](#wait) |
unshackle skips an entry whose `event` or `mode` is not one of the listed values, and logs a
warning that names the bad value, once per command. unshackle also skips an entry whose
@@ -66,15 +67,30 @@ means a path containing spaces always arrives as a single argument on every OS.
history of letting a crafted value break out (CVE-2024-3566). Call the interpreter and
pass the script as an argument (`python upload.py`, `pwsh -File upload.ps1`) instead.
-Scripts are fire and forget. unshackle starts the process, writes the command to the debug
-log, and carries on. It does not wait for the script, capture its output, time it out, or
-change its own exit code when a script fails. A script keeps running if unshackle exits
-first, and Ctrl+C during a season pack does not kill the scripts
-already started.
+By default, scripts are fire and forget. unshackle starts the process, writes the command to
+the debug log, and carries on. It does not wait for the script, capture its output, time it
+out, or change its own exit code when a script fails. A script keeps running if unshackle
+exits first, and Ctrl+C during a season pack does not kill the
+scripts already started.
!!! note "One process per file"
In `file` mode a large season pack starts one process per episode with nothing
- throttling them. If your script is heavy, queue the work inside it or use `mode: season`.
+ throttling them. If your script is heavy, set `wait: true`, queue the work inside the
+ script, or use `mode: season`.
+
+### Waiting for a script { #wait }
+
+```yaml title="unshackle.yaml"
+post_scripts:
+ - command: "python /opt/upload.py --file={filepath}"
+ wait: true
+```
+
+With `wait: true`, unshackle waits until the script exits, then writes the exit code to the
+debug log and carries on. Because the `file` hook runs between titles, unshackle runs one
+script at a time over a season pack instead of starting them all at once. unshackle only
+logs the exit code: a failing script does not fail the download or change unshackle's own
+exit code. `--postscript` entries never wait.
## Variables
@@ -245,9 +261,10 @@ title object already knew: `{title}`, `{title_raw}`, `{title_id}`, `{year}`, `{s
comes from the naming context, such as `{quality}`, `{hdr}`, `{artist}` and `{album}`, is
empty.
-A resumed `--continue-downloads` download that finishes runs `success` as usual. Because
-unshackle does not wait for your script, it never sees its exit code, so a failing script
-is not reported anywhere. Your script owns its own error handling and logging.
+A resumed `--continue-downloads` download that finishes runs `success` as usual. unshackle
+sees your script's exit code only when that entry sets `wait: true`, and even then it only
+writes the code to the debug log. Nothing else reports a failing script. Your script owns
+its own error handling and logging.
A `success` hook always names a file this run wrote. There is no skip-if-exists path in
`dl` today, so nothing fires for a title that was not downloaded.
diff --git a/tests/test_post_scripts.py b/tests/test_post_scripts.py
index 94a15cbd..2aa0c495 100644
--- a/tests/test_post_scripts.py
+++ b/tests/test_post_scripts.py
@@ -154,7 +154,7 @@ def test_dispatch_survives_an_unbalanced_quote(caplog):
)
def test_malformed_post_scripts_config_shapes(monkeypatch, raw, expected):
monkeypatch.setattr(config, "post_scripts", raw)
- assert list(_entries("success", "file")) == expected
+ assert [c for c, _ in _entries("success", "file")] == expected
def test_typoed_event_or_mode_warns_instead_of_silently_dropping(monkeypatch, caplog):
@@ -165,7 +165,7 @@ def test_typoed_event_or_mode_warns_instead_of_silently_dropping(monkeypatch, ca
[{"command": "typo.py", "mode": "seson"}, {"command": "ok.py", "mode": "season"}],
)
for dispatch_mode in ("file", "season", "run"):
- assert list(_entries("success", dispatch_mode)) == (["ok.py"] if dispatch_mode == "season" else [])
+ assert [c for c, _ in _entries("success", dispatch_mode)] == (["ok.py"] if dispatch_mode == "season" else [])
assert caplog.text.count("unknown event/mode") == 1 # warned once, not per dispatch
@@ -196,3 +196,24 @@ def test_tagging_ids_are_read_at_dispatch_not_snapshotted():
if __name__ == "__main__":
raise SystemExit(pytest.main([__file__, "-q"]))
+
+
+def _dispatch_seconds(monkeypatch, entry: dict) -> float:
+ import time
+
+ monkeypatch.setattr(config, "post_scripts", [entry])
+ start = time.monotonic()
+ dispatch("success", "file", {})
+ return time.monotonic() - start
+
+
+def test_wait_true_waits_for_the_script_and_logs_the_exit_code(monkeypatch, caplog):
+ caplog.set_level("DEBUG", logger="post-script")
+ slow = 'python -c "import time,sys; time.sleep(0.3); sys.exit(3)"'
+ assert _dispatch_seconds(monkeypatch, {"command": slow, "wait": True}) >= 0.3
+ assert "Post-script exited 3" in caplog.text
+
+
+def test_wait_defaults_to_fire_and_forget(monkeypatch):
+ slow = 'python -c "import time; time.sleep(0.3)"'
+ assert _dispatch_seconds(monkeypatch, {"command": slow}) < 0.3
diff --git a/unshackle/core/utils/post_scripts.py b/unshackle/core/utils/post_scripts.py
index 20757238..2af01834 100644
--- a/unshackle/core/utils/post_scripts.py
+++ b/unshackle/core/utils/post_scripts.py
@@ -6,8 +6,10 @@ is what makes a title like ``Bob"; rm -rf ~`` harmless: a value can never become
token or a shell operator. The cost is that the command has no shell features and no
interpreter lookup, so users name the interpreter themselves (``python upload.py``).
-Scripts are fire-and-forget: unshackle spawns them, logs the command, and moves on. It
-does not wait, capture output, time them out, or let a script's exit code change its own.
+Scripts are fire-and-forget by default: unshackle spawns them, logs the command, and moves
+on. With ``wait: true`` unshackle waits for the script to exit, which runs heavy scripts one
+at a time over a season pack. It logs the exit code, but a script never changes unshackle's
+own exit code, and unshackle never captures output or times a script out.
"""
from __future__ import annotations
@@ -151,11 +153,11 @@ def season_context(context: dict[str, str], folder: Path) -> dict[str, str]:
return out | {"folder": str(folder)}
-def _entries(event: str, mode: str, overrides: Sequence[str] = ()) -> Iterator[str]:
- """Commands configured for this event and mode. --postscript replaces the config list."""
+def _entries(event: str, mode: str, overrides: Sequence[str] = ()) -> Iterator[tuple[str, bool]]:
+ """``(command, wait)`` pairs for this event and mode. --postscript replaces the config list."""
if overrides:
if event == "success" and mode == "file":
- yield from overrides
+ yield from ((command, False) for command in overrides)
return
raw = config.post_scripts
@@ -189,12 +191,12 @@ def _entries(event: str, mode: str, overrides: Sequence[str] = ()) -> Iterator[s
continue
if entry_event != event or entry_mode != mode:
continue
- yield command
+ yield command, bool(entry.get("wait", False))
def dispatch(event: str, mode: str, context: dict[str, str], overrides: Sequence[str] = ()) -> None:
"""Spawn every post-script configured for `event` and `mode`. Never raises."""
- for command in _entries(event, mode, overrides):
+ for command, wait in _entries(event, mode, overrides):
try:
tokens = tokenize(command)
except ValueError as e: # shlex: unbalanced quote in the command template
@@ -224,6 +226,15 @@ def dispatch(event: str, mode: str, context: dict[str, str], overrides: Sequence
else {"start_new_session": True}
)
try:
- subprocess.Popen(argv, stdin=subprocess.DEVNULL, **detach)
+ proc = subprocess.Popen(argv, stdin=subprocess.DEVNULL, **detach)
except (OSError, ValueError) as e:
log.warning("Post-script failed to start (%s): %s", e, redact_text(redact_path(argv[0])))
+ continue
+ if wait:
+ rc = proc.wait()
+ log.debug("Post-script exited %s: %s", rc, safe_command)
+ log_event(
+ "post_script_exit",
+ message=f"Post-script for {event}/{mode} exited {rc}",
+ context={"event": event, "mode": mode, "command": safe_command, "returncode": rc},
+ )