How to Use the Command 'afplay' (with Examples)

The afplay command is a handy tool for those who wish to play audio files directly from the command line on macOS systems. It is a simple yet powerful command-line audio player that allows users to play sound files and offers several options for manipulating audio playback. Whether you’re a developer testing audio output, a film editor previewing sound effects, or someone who just prefers using the terminal, afplay can be immensely practical.

With afplay, users can adjust the speed of playback or limit playback to a specific duration, providing versatility for various audio playback needs.

Use Case 1: Play a Sound File (Waits Until Playback Ends)

Code:

afplay path/to/file

Motivation:

The primary use of the afplay command is to play an audio file directly from the terminal. This can be extremely useful for individuals working in a command-line environment who need to quickly verify or test audio files without switching contexts or opening a separate audio playback application. Whether you’re scripting, developing software, or even setting up a sound-based notification system, the ability to play audio from the terminal swiftly enhances workflow efficiency.

Explanation:

• afplay: The command itself invokes the audio player from the terminal.
• path/to/file: This is the path to the sound file you wish to play. The file must be accessible from the terminal, and the path can be absolute or relative.

Example Output:

When you execute this command, the audio file will start playing through your default output device (e.g., speakers or headphones). There isn’t a text output, but you’ll hear the playback of the specified file until it ends.

Use Case 2: Play a Sound File at 2x Speed (Playback Rate)

Code:

afplay --rate 2 path/to/file

Motivation:

Playing a sound file at double speed can be helpful in various scenarios, such as quickly skimming through audio content, reviewing recordings to pinpoint specific sections, or testing how audio handles different playback speeds without editing the original file. This is particularly valuable for audio engineers, musicians, or developers working with audio who might need to process or audit lengthy audio segments rapidly.

Explanation:

• afplay: Initiates the playback of the specified audio file.
• --rate 2: This flag sets the rate of playback to double the normal speed. It is a simple way to adjust how fast the audio plays back without altering its pitch.
• path/to/file: Represents the path to the desired audio file.

Example Output:

The audio file will start playing at double the normal speed. You won’t receive any visual output, but you’ll notice the quicker tempo audibly.

Use Case 3: Play a Sound File at Half Speed

Code:

afplay --rate 0.5 path/to/file

Motivation:

Playing an audio file at half speed can be exceptionally useful for language learners, musicians, or researchers who need to analyze sound details more minutely, transcribe speech, or practice musical pieces. This reduced speed enables users to catch subtle nuances in the audio that might be missed at normal speed.

Explanation:

• afplay: Calls the command to play the designated audio file.
• --rate 0.5: Sets the playback rate to 50% of the normal speed, effectively halving it. This makes the audio play slower without changing the pitch.
• path/to/file: Indicates the file path for the audio file to be played.

Example Output:

You’ll hear the audio file at a slower pace than usual through your audio playback device, allowing for detailed examination of the sound. No text is displayed during this playback.

Use Case 4: Play the First N Seconds of a Sound File

Code:

afplay --time seconds path/to/file

Motivation:

In scenarios where you need to play only a portion of an audio file—such as in previewing or auditing segments, or using audio samples in presentations or demonstrations—this command option is perfect. It ensures that you can listen to exactly the segment you need without manual intervention or external editing.

Explanation:

• afplay: The command used to initiate playback.
• --time seconds: This option specifies the playback duration in seconds. It tells afplay how long to play the file before stopping.
• path/to/file: The path indicates which audio file to process.

Example Output:

Executing this command plays only the first ‘N’ seconds specified by the --time option. The audio halts automatically after this duration with no further terminal messages, ensuring precise control over playback.

Conclusion:

The afplay command is a versatile and efficient tool, providing several options for audio playback directly from the terminal. Its ability to manage playback speed and duration makes it an essential utility in many professional and personal contexts. Whether you’re testing, analyzing, or simply enjoying audio, afplay tailors to specific needs through intuitive command-line options.