Hi! ----
Question mainly for Glenn:
Is it possible to do regex matching&&extraction via read(1) which then
fills variables (or an array) with the matches ? The issue is that
while the (attached as "json2cpv.sh") JSON parser demo works it has
limitations because it requires to do all operations in-memory because
it relies on ksh93's pattern matching&&extration feature
${s//pattern/replacement}+".sh.match".
AFAIK I need something like this:
-- snip --
while read -P "<pattern>" match1 match2 match3 ; do
<... parse_data ...>
done <"input_file.json"
-- snip --
... where read(1) option -P defines the pattern to be used and matches
are stored in the variables match1...match3 (or if -A is set in an
indexed+sparse array (like .sh.match works))
The question is whether this is possible... AFAIK the issue are...
- ... pattern matching needs to read ahead... at some point there's no
gurantee that the seek pointer can't be put back at the original
position if the match fails and the input is a pipe, right (even
"lookahead" via I_PEEK has AFAIK size limitations and is not
(currently) not available on Linux for pipes/fifofs) ? What should we
do then ?
- ... performance: each read(1) cycle has to re-parse the pattern...
the pattern cache will avoid most of the overhead, right ?
----
Bye,
Roland
--
__ . . __
(o.\ \/ /.o) [email protected]
\__\/\/__/ MPEG specialist, C&&JAVA&&Sun&&Unix programmer
/O /==\ O\ TEL +49 641 3992797
(;O/ \/ \O;)
json2cpv.sh
Description: Bourne shell script
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