How to Replay Commands with 'scriptreplay' (with examples)

The scriptreplay command is an essential utility for developers and system administrators who wish to revisit the terminal activities recorded by the script command. It allows you to replay terminal sessions (typescript files) exactly as they were executed, along with the intervals between keypresses and commands. This can be incredibly useful for training, debugging, and creating tutorials by showing how specific tasks were executed in real time. The scriptreplay tool takes a timing file and a typescript file as input and reproduces the terminal session on the user’s screen.

Use case 1: Replay a typescript at the speed it was recorded

Code:

scriptreplay path/to/timing_file path/to/typescript

Motivation:
Replaying a typescript at its original speed is useful when you want to accurately review a session to understand each step taken and the time it took. This can help you analyze the workflow and identify any errors, inefficiencies, or improvements. For educators or developers creating documentation, maintaining the original timing can make tutorials realistic, helping learners mentally process each step at a natural pace.

Explanation:

• scriptreplay: The main command used to start the replay.
• path/to/timing_file: Specifies the file containing timing data recorded during the original session. This file ensures that each action is replayed with the exact timing as originally captured.
• path/to/typescript: The file containing the recorded session’s output. This file is essentially the command execution log which scriptreplay replays.

Example Output:
The terminal outputs the same sequence of commands and their outputs that were in the original recorded session. This includes prompts, command execution results, and any errors that might have occurred, with pauses occurring just as they did during the original session.

Use case 2: Replay a typescript at double the original speed

Code:

scriptreplay path/to/timingfile path/to/typescript 2

Motivation:
Replaying a typescript at double the original speed can be beneficial for users who want to quickly scan through the contents of the recorded session, skipping redundant delays. This use case is particularly useful for experienced users familiar with the tasks being demonstrated, allowing them to get a faster overview without unnecessary waiting time.

Explanation:

• scriptreplay: Initiates the replay of the recorded session.
• path/to/timingfile: Refers to the recorded timing data of the session. This file contains relevant delay data between each command.
• path/to/typescript: Points to the recorded session output.
• 2: A speed multiplier that accelerates the replay to twice its normal speed.

Example Output:
The terminal reproduces the entire recorded session at a faster pace than originally captured. The commands and outputs flash by quickly, ideal for users who need a rapid review without lingering pauses.

Use case 3: Replay a typescript at half the original speed

Code:

scriptreplay path/to/timingfile path/to/typescript 0.5

Motivation:
Playing back a typescript at half the speed could be crucial for novice users or in scenarios requiring detailed examination of complex command sequences. This approach enables learners to follow along more easily and does not overwhelm them with rapid information delivery, making it easier to take notes or comprehend each step thoroughly.

Explanation:

• scriptreplay: The command used to replay the recorded session.
• path/to/timingfile: This is the file housing the original session’s timing details.
• path/to/typescript: Denotes the file that contains the terminal output and command sequence that will be replayed.
• 0.5: Indicates playing the recorded session at half the original speed, providing a more stretched out and comprehensible viewing experience.

Example Output:
The terminal session plays back at a significantly slowed pace, allowing users to observe each command execution and the corresponding results leisurely, which is beneficial for scrutinizing steps during training or troubleshooting.

Conclusion:

The scriptreplay command is a robust tool that recreates terminal sessions with precision, whether at regular, accelerated, or decelerated speeds. By understanding how to utilize this command effectively, users can gain insights into recorded workflows, support educational efforts, and enhance debugging processes. Each of these use cases allows flexibility and control over how terminal sessions are reviewed, thus catering to different user needs and learning styles.