Description

[ .. ] aka test can not match against globs.

In bash/ksh, you can instead use [[ .. ]] which supports this behavior.

In sh, you can rewrite to use grep.

Example of incorrect code:

if [ $var == *[^0-9]* ]
then
  echo "$var is not numeric"
fi

Example of correct code:

if [[ $var == *[^0-9]* ]]
then
  echo "$var is not numeric"
fi

Exceptions

None. If you are not trying to match a glob, quote the argument (e.g. [ $var == '*' ] to match literal asterisk.