/**
 * Input used by an ExternalCommand, exists in the main UI not webworker.
 * This effectively wraps a real IInput in the webworker ShellImpl IContext.
 */
export interface IExternalInput {
    isTerminal(): boolean;
    readAsync(maxChars: number | null): Promise<string>;
}
export declare class ExternalInput implements IExternalInput {
    readonly callback: (maxChars: number | null) => Promise<string>;
    constructor(callback: (maxChars: number | null) => Promise<string>, isTerminal: boolean);
    isTerminal(): boolean;
    readAsync(maxChars: number | null): Promise<string>;
    private _isTerminal;
}