/**
 * PM2-client-free log tailing for `botmux logs`.
 *
 * `pm2 logs` is a PM2 client, and any PM2 client invoked with no live God
 * lazily births one (pm2 Client.start → pingDaemon false → launchDaemon).
 * That made the read command a check/use race against `restart
 * --include-pm2`: a God observed under the fleet lock could be retired after
 * the lock released but before the spawned client connected, and the
 * connecting client would then create a replacement God inside the
 * kill→start window. Tailing the log FILES pm2 itself writes removes the PM2
 * client entirely — no interleaving of this command can create a God, and
 * logs keep working while the fleet is stopped.
 */
export interface LogTailSource {
    /** Display label, e.g. the PM2 process name. */
    label: string;
    stream: 'out' | 'err';
    file: string;
}
export declare function formatLogLine(source: LogTailSource, line: string): string;
/** Last `n` complete lines of a text chunk (trailing newline ignored). */
export declare function lastLinesOfChunk(chunk: string, n: number): string[];
export interface LogFileFollowerOptions {
    sources: readonly LogTailSource[];
    writeLine: (formatted: string) => void;
    pollIntervalMs?: number;
}
/**
 * Print the last N lines of every existing source, then follow appends.
 * Correctness boundaries this models explicitly:
 *  - An unterminated trailing line is NEVER emitted as a line; it is carried
 *    as `partial` (from the initial tail too) and emitted once completed, so
 *    "abc" + later "def\n" prints one "abcdef" line.
 *  - Atomic rotation (rename + recreate at the same path) is detected by
 *    dev+ino generation identity, not by size heuristics — a new file whose
 *    size already exceeds the old offset would otherwise be read mid-stream.
 *    (On filesystems reporting ino=0 this degrades to the size checks.)
 *  - In-place truncation (`pm2 flush`) resets to the top of the new content.
 *  - Files may appear later (fleet starts while tailing) or disappear.
 */
export declare class LogFileFollower {
    private readonly states;
    private readonly writeLine;
    private readonly pollIntervalMs;
    private timer;
    constructor(opts: LogFileFollowerOptions);
    /** Emit the initial `--lines` window and position offsets at end-of-file. */
    printInitialTail(lines: number): void;
    start(): void;
    stop(): void;
    /** One poll pass; exposed so tests can drive it deterministically. */
    pollOnce(): void;
}
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