Ollama: Ollama: improve existing draft article

2026-10-26T22:45:48Z

Ollama: improve existing draft article

← Older revision		Revision as of 22:45, 26 October 2026
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			In computing, [[Pipefail]] refers to a shell option in Bash that modifies the behavior of pipeline exit statuses. This feature affects how command pipelines return status codes, influencing script reliability and error handling. When [[Pipefail]] is enabled, pipelines behave differently compared to their default state, making it a critical consideration for advanced shell scripting.

			{{H2\|Technical Details}}
	<blockquote>
	"The ~~return~~ ~~status~~ of a pipeline is the exit status of the last command, ~~unless~~ ~~the~~ ~~pipefail~~ ~~option~~ is ~~enabled.~~ ~~If pipefail~~ is enabled, the pipeline's return status is the ~~value~~ of the last (rightmost) command to ~~exit with a non-zero status~~, or zero if all commands ~~exit successfully~~. If ~~the~~ ~~reserved~~ ~~word~~ ! ~~precedes~~ a pipeline, ~~the~~ ~~exit status of that pipeline is the logical negation of the exit status as described above. The shell waits for all commands in the pipeline to terminate before returning a value~~."		The default behavior of a pipeline in Bash is to return the exit status of the last command executed within it. However, when the [[Pipefail]] option is enabled, the pipeline's return status changes to reflect the exit status of the last (rightmost) command that failed, or zero if all commands succeed. This modification allows scripts to detect failures in earlier stages of a pipeline, improving error detection capabilities.

	</blockquote>
			Key aspects of [[Pipefail]] include:
			- Default Pipeline Behavior: Without [[Pipefail]], only the final command's status is considered.
			- [[Pipefail]]-Enabled Behavior: The pipeline returns the status of the first failing command, if any.
			- Negation with '!': If the reserved word '!' precedes a pipeline, the exit status is logically negated (success becomes failure and vice versa).
			- Synchronous Execution: The shell waits for all commands in the pipeline to complete before returning a value, ensuring consistent behavior.

			{{H2\|Usage in Shell Scripts}}
			Enabling [[Pipefail]] is typically done via the `set -o [[Pipefail]]` command within a script. This is particularly useful in scenarios where intermediate command failures need to be detected, such as in data processing pipelines or validation workflows. For example, a pipeline like `command1 \| command2 \| command3` will fail if any of the commands (e.g., `command1`) returns a non-zero status when [[Pipefail]] is active.

			{{H2\|Historical Context}}
			The [[Pipefail]] option was introduced to address limitations in early shell implementations, where pipeline failures could be silently ignored if later commands succeeded. This change aligns with modern scripting practices that prioritize explicit error handling and robustness.

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	{{Draft}}
			{{Ollama}}
			{{Pending Human Review}}

Robert Brockway at 02:59, 14 February 2024

2024-02-14T02:59:05Z

← Older revision		Revision as of 02:59, 14 February 2024
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			<blockquote>

			"The return status of a pipeline is the exit status of the last command, unless the pipefail option is enabled. If pipefail is enabled, the pipeline's return status is the value of the last (rightmost) command to exit with a non-zero status, or zero if all commands exit successfully. If the reserved word ! precedes a pipeline, the exit status of that pipeline is the logical negation of the exit status as described above. The shell waits for all commands in the pipeline to terminate before returning a value."
			</blockquote>

	{{BASH}}		{{BASH}}

Robert Brockway: Created page with " {{BASH}} {{Draft}}"

2024-02-14T02:58:05Z

Created page with " {{BASH}} {{Draft}}"

New page

Pipefail - Revision history

Ollama: Ollama: improve existing draft article

Robert Brockway at 02:59, 14 February 2024

Robert Brockway: Created page with " {{BASH}} {{Draft}}"