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SC2006

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Xiao Liang edited this page Jan 27, 2017 · 19 revisions

Use $(STATEMENT) instead of legacy `STATEMENT`

Problematic code

echo "Current time: `date`"

Correct code

echo "Current time: $(date)"

Rationale

Backtick command substitution `STATEMENT` 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.

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

Exceptions

None.

See also

Enjoy what I am trying to create as I am the creator

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