3 SC2176

Joachim Ansorg edited this page 2021-11-12 19:44:05 +01:00

Table of Contents

• time is undefined for pipelines. time single stage or bash -c instead.
• Problematic code:
• Correct code:
• Rationale:
• Exceptions:

time is undefined for pipelines. time single stage or bash -c instead.

Problematic code:

time foo | bar

Correct code:

To time the most relevant stage:

foo | { time bar; }

To time everything in a pipeline:

time bash -c 'foo | bar'

Note that you can not use time sh -c to time an entire pipeline, because POSIX does not guarantee that anything other than the last stage is waited upon by the shell.

Rationale:

This behavior is explicitly left undefined in POSIX.

Exceptions:

None. This warning is not emitted in ksh or bash where time is defined for pipelines.

ShellCheck

• Installation

  • CentOS6
  • More Installation Guides

• Usage

  • Directive
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• Integrating and extending

  • Misc. contributions
  • Azure Pipelines
  • Buildkite
  • CircleCI
  • DevGuide
  • Integration
  • JUnit
  • Phabricator
  • TravisCI
  • GitLab CI
  • Drone
  • GitHub Actions

• Severity

• Template

Each individual ShellCheck warning has its own wiki page like SC1000. Use GitHub Wiki's "Pages" feature above to find a specific one, or see Checks.