The exit codes treated as success (from `Command.OkCodes`; `{0}` by default).

The exit code, or `None` for a signal kill or timeout.

The captured stdout and stderr joined into one string — stdout, then stderr on a new line when both are non-empty (for a `byte[]` stdout, UTF-8-decoded). Shares the exact join rule with `ProcessError.Combined`. This is a **post-hoc concatenation** of the two *separately* captured streams, so it does **not** reproduce their real terminal interleaving. For an honest, byte-for-byte `2>&1` view use `Command.MergeStderr`, which merges the streams at the OS level: the interleaved output then arrives on `Stdout` (and `Stderr` is empty, so `Combined` equals `Stdout`).

Wall-clock duration of the run.

Demand a successful run (an **accepted** exit code — one in `Command.OkCodes`, `{0}` by default): returns the result unchanged on success, otherwise the corresponding `ProcessError` (`Exit` / `Signalled` / `Timeout`). The instance form for C# fluency.

True when the process exited with one of the accepted codes (`Command.OkCodes`; `{0}` by default).

True when the run was killed for exceeding its timeout.

How the run concluded.

True when any of `needles` appears (case-insensitive, ordinal) in either captured stream — the "a specific non-zero exit is benign when a known stdout/stderr marker is present" idiom (e.g. a tool exiting 1 with `no changes` in its output). Each stream is searched independently, so a needle never matches across the stdout/stderr boundary; a null needle is skipped and an empty `needles` is `false`.

The program that was run.

The terminating signal, when known.

The captured stderr, as decoded text.

The captured stdout (decoded text or raw bytes, depending on the verb).

True when the captured output was truncated by an output-buffer policy.