> This patch modfies expr to use portable POSIX regex rather than BSD
> regex.
...
> This updated patch implements an anchored regex by checking that the
> match starts at offset 0.
More to the point, this patch uses the same regex that sed.c is already using
(opportunity to suck in less library code), and even building a dynamically
linked busybox with just expr the result is a slightly smaller binary (by 94
bytes, I dunno what nm --size-sort has to say about it because I didn't build
with debug info, since that changes the binary size a lot by disabling
optimization...)
Your mileage may vary. Handle with caution. Do not taunt happy fun ball.
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