koalaman / shellcheck Public
SC3056
Vidar Holen edited this page Sep 2, 2020
·
1 revision
In POSIX sh, name matching prefixes are undefined.
(or "In dash, ... are not supported." when using dash)
Problematic code:
#!/bin/sh
echo "${!ANDROID_*}"Correct code:
The easiest solution is to switch to a shell that does support name matching prefixes, like bash:
#!/bin/bash
echo "${!ANDROID_*}"Alternatively, extract the data you want from env or set
Rationale:
Using ${!name*} to find all variable names with a given prefix is a bash and ksh extension that dash and POSIX sh does not support.
Exceptions:
If you only intend to target shells 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!