> how about add the keyword local which makes the variables not global. No. It's not portable and not standard, and will break with a lot of shells which ffmpeg currently supports.
Different shells have different ways to limit a variable scope to the current function, some don't have a way at all, and some limits some variables automatically (like the value variable in a `for` command). There are only two standard ways for limited-scope values: - A function's positional parameters are local to each instance (including each instance in a recursion). - A subshell prevents all changes to variables outside of it, with two issues: 1. Code can't actually modify any variables outside of its subshell... 2. It can be very expensive where/if (a big if) performance matters. There are ways to implement locality of variables while staying portable. In ffmpeg's configure `pushvar` and `popvar` were used for such functionality (they still exist in configure but currently unused). Their usage was replaced with a method based on storing prior values in positional parameter (in a recursive function) and restoring them later. There are also more generic solutions, with varying degrees of complexity and performance. I wrote such solution myself, and some day I might send a patch to ffmpeg which incorporates it. Till then, there's no generic way to set local variables in `configure` except the two methods mentioned above, or using a unique enough name. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
