2 SC3037

Vidar Holen edited this page 2021-09-16 20:10:53 -07:00

Table of Contents

• In POSIX sh, echo flags are undefined.
• Problematic code:
• Correct code:
• Rationale:
• Exceptions:
• Related resources:

In POSIX sh, echo flags are undefined.

Problematic code:

#!/bin/sh
echo -ne 'Foo:\tBar'

Correct code:

Rewrite in terms of the more robust and standardized printf:

#!/bin/sh
printf 'Foo:\tBar'

Rationale:

echo has historically behaved differently on different systems. Use printf instead to ensure compatibility between shells.

Exceptions:

If you only intend to target systems that supports this feature, you can change the shebang to a shell that guarantees support, or ignore this warning.

You can use # shellcheck disable=SC3000-SC4000 to ignore all such compatibility warnings.

Related resources:

• Help by adding links to BashFAQ, StackOverflow, man pages, POSIX, etc!

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