[PATCH] config: use simpler regexp syntax to get dot version
spitzak at gmail.com
Wed Apr 8 12:48:10 PDT 2015
On 04/08/2015 12:15 AM, Pekka Paalanen wrote:
>> + dot_version=`$DOT -V 2>&1|$GREP -o ['[0-9]*\.[0-9]*\.[0-9]*']`
>> AS_VERSION_COMPARE([$dot_version], [2.26.0],
>> AC_MSG_ERROR([Graphviz dot $dot_version too old. Graphviz 2.26+ required for documentation build. Install required graphviz version or disable the documentation using --disable-documentation])],
> For the record, I think those @<:@ and @:>@ are square brackets. They
> are just an M4 escape thing to prevent M4 from interpreting those
> square brackets and possibly removing them.
> Oh yeah, "quadrigraphs":
> It's just another way to protect the square brackets. Your way should
> work fine here too, since these are not M4 macro arguments.
Egad, M4 is a mess.
Anyway it is possible the following is better:
$EGREP -o ['[0-9]+\.[0-9]+\.[0-9]+']
This will prevent it from matching the text ".." if for some reason dot
prints that before the version number.
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