pw-play:tldr:031ea

The command pw-play ${filename-wav} is likely a Unix/Linux command that employs variable substitution. Here is a breakdown of its components:

1. pw-play: This is the name or path of an executable binary or script. It is the actual command being invoked.
2. ${filename-wav}: This is a variable placeholder that will be substituted with the actual filename of a WAV file when the command is executed. The format ${variable} is used for variable substitution in Unix/Linux shells, where variable is the name of the variable.

When the command is executed, the ${filename-wav} placeholder will be replaced with the actual filename of a WAV file, and the resulting command will be run. For example, if the variable filename-wav has the value audio.wav, the command will become pw-play audio.wav. The purpose of this command would depend on the functionality of pw-play, which is not clear from the given information.