Envoyé par man bash
${parameter%word}
${parameter%%word}
The word is expanded to produce a pattern just as in pathname expansion. If the pattern matches a trailing portion of the expanded
value of parameter, then the result of the expansion is the expanded value of parameter with the shortest matching pattern (the ``%''
case) or the longest matching pattern (the ``%%'' case) deleted. If parameter is @ or *, the pattern removal operation is applied to
each positional parameter in turn, and the expansion is the resultant list. If parameter is an array variable subscripted with @ or *,
the pattern removal operation is applied to each member of the array in turn, and the expansion is the resultant list.
