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Full Discussion: Plan9 sed - rationale for limitations
Top Forums UNIX for Dummies Questions & Answers Plan9 sed - rationale for limitations Post 302681909 by uiop44 on Saturday 4th of August 2012 08:44:46 PM
Old 08-04-2012
Plan9 sed - rationale for limitations
Using the 9base port in {Net,Free}BSD, it appears that Plan 9's sed

1. restricts the max number of sed commands and thereby the length of sed scripts

2. does not recognise the \nn flag where nn is the number of a matched substring. See example below.

Questions:

1. Why would they limit the max number of sed commands?

2. Plan 9's regexp library is not the same as BSD's? (It's probably better hence my curiosity.) So the rules of re_format(7) do not apply? Is it not possible to match substrings, as below?

Code:
echo abcd|sed 's/\(.*b\)\(.*\)/\2\1/' 

FreeBSD sed: cdab 

Plan 9 sed:abcd

sed -f long_list_of_cmds.sed 

FreeBSD: (no problem) 

Plan 9:  "Too many commands"

Is it that the Plan 9 utils like sed and grep use ERE by default, instead of BRE? No BRE in Plan 9 utils?
 

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LEARN ABOUT DEBIAN

rdf::query::plan::thresholdunion

RDF::Query::Plan::ThresholdUnion(3pm)			User Contributed Perl Documentation		     RDF::Query::Plan::ThresholdUnion(3pm)

NAME

       RDF::Query::Plan::ThresholdUnion - Executable query plan for unions.

VERSION

       This document describes RDF::Query::Plan::ThresholdUnion version 2.908.

METHODS

       Beyond the methods documented below, this class inherits methods from the RDF::Query::Plan class.

       "new ( $time, @plans )"
       "execute ( $execution_context )"
       "next"
       "close"
       "children"
       "threshold_time"
       "optimistic"
       "default"
       "distinct"
	   Returns true if the pattern is guaranteed to return distinct results.

       "ordered"
	   Returns true if the pattern is guaranteed to return ordered results.

       "plan_node_name"
	   Returns the string name of this plan node, suitable for use in serialization.

       "plan_prototype"
	   Returns a list of scalar identifiers for the type of the content (children) nodes of this plan node. See RDF::Query::Plan for a list of
	   the allowable identifiers.

       "plan_node_data"
	   Returns the data for this plan node that corresponds to the values described by the signature returned by "plan_prototype".

       "graph ( $g )"

AUTHOR

	Gregory Todd Williams <gwilliams@cpan.org>

perl v5.14.2							    2012-01-31				     RDF::Query::Plan::ThresholdUnion(3pm)
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