Red Hat Bugzilla – Bug 163330
can't support the "egrep" pattern such as "word\W"
Last modified: 2007-11-30 17:11:10 EST
Description of problem: The cscope has a option "Find this egrep pattern:".But when input the "word\W" and search, it says "Could not find the egrep pattern: word\W". But the egrep application can find the "word\W". Version-Release number of selected component (if applicable): cscope-15.5-12 How reproducible: Steps to Reproduce: 1.build the cross refences file cscope.out 2.invoke the cscope 3.use the "Find this egrep pattern:" to find a pattern such as "word\W" Actual results: although the "word\W" exists, but cscope can't find it. Expected results: cscope could find the pattern. Additional info:
It turns out there are many versions of egrep. cscope contains its own little egrep implementation, probably pulled out of an older SystemV UNIX, which predates some modern constructs. Operators like [:alnum:] or \w were not supported in this version. I expect that cscope screen's reference to "egrep" was meant more to indicate that a wider class of regexps are supported than plain grep: alternation, repetition, and so on. I hope this explains (my guess at) the reasons for the problem. Extending cscope's egrep engine is probably not practical. I can't think of a different term to put on the user interface that doesn't suffer from this ambiguity. I think we'll have to live with this problem.