Proposal for a New Bash Option: failfast for Immediate Pipeline Failure

[ama bamo]

Dear Bash Maintainers,

I have encountered a challenge with the current implementation of pipelines
in Bash, specifically regarding subshells and the pipefail option. As
documented, each command in a pipeline is executed in its own subshell, and
Bash waits for all commands in the pipeline to terminate before returning a
value.

To address these issues, I propose the introduction of a new option,
failfast, which would immediately terminate the pipeline if any command in
the pipeline fails. This would streamline error handling and provide more
predictable script execution, aligning with user expectations in many
common use cases.

Here is an example illustrating the proposed behavior:
````

#!/bin/bash
set -o failfast
nonexisting-command | sleep 10# Pipeline exits immediately without
sleeping for 10 seconds
````

This would provide a more intuitive and robust error handling mechanism for
pipeline commands, enhancing the usability and reliability of Bash
scripting.

I look forward to your feedback.

Best regards,

Mateusz Kurowski