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SC2006

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koalaman edited this page Jan 25, 2015 · 19 revisions

Use $(..) instead of legacy `..`

Problematic code:

echo "Current time: `date`"

Correct code:

echo "Current time: $(date)"

Rationale:

Backtick command substitution `..` is legacy syntax with several issues.

  1. It has a series of undefined behaviors related to quoting in POSIX.
  2. It imposes a custom escaping mode with surprising results.
  3. It's exceptionally hard to nest.

$(..) command substitution has none of these problems, and is therefore strongly encouraged.

Exceptions

None.

ShellCheck

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