yeah you explain that well. thanks. Andy Bach 写道:
> But it doesn't work for this case:$ perl -le '$x="/path/"; print 1 if $x=~m{path/\w+}' > it expects 1 returned.Well, assuming you mean it shouldn't match as $x starts with a slash and the RE doesn't - you're on the right path. The reason is, the match goes anywhere, it is "unanchored" so Perl happily says, "walking" down $x saying: "slash? nope. "p"? match! "a" match!! ... slash? yay! one or more ("+") word chars ("\w")? Aw, fail"so, actually that RE fails: $ perl -le '$x="/path/"; print 1 if $x=~m{path/\w+}' [crickets] as there's not even 1 "\w" $ perl -le '$x="/path/"; print 1 if $x=~m{path/\w}' zero or more ("*") works $ perl -le '$x="/path/"; print 1 if $x=~m{path/\w*}' 1 as does none $ perl -le '$x="/path/"; print 1 if $x=~m{path/}' 1 and adding the initial "/" to the RE still works: $ perl -le '$x="/path/"; print 1 if $x=~m{/path/}' 1but if you'd anchored ("^" - zero-width "at the beginning of the string" must be at the begining of the RE) your RE would fail too:$ perl -le '$x="/path/"; print 1 if $x=~m{^path/}' because the RE starts w/ "p" and the $x starts with slash.On Tue, Jul 17, 2018 at 6:56 AM, Lauren C. <lau...@miscnote.net <mailto:lau...@miscnote.net>> wrote:Hello, I want to match: /path/ /path/123 /path/abc but /path/?xxx should not be matched. This works: $ perl -le '$x="/path/abc"; print 1 if $x=~m{path/\w+}' 1 this works too: $ perl -le '$x="/path/?abc"; print 1 if $x=~m{path/\w+}' But it doesn't work for this case: $ perl -le '$x="/path/"; print 1 if $x=~m{path/\w+}' it expects 1 returned. Can you help? thanks.-- To unsubscribe, e-mail: beginners-unsubscr...@perl.org<mailto:beginners-unsubscr...@perl.org> For additional commands, e-mail: beginners-h...@perl.org <mailto:beginners-h...@perl.org> http://learn.perl.org/ -- a Andy Bach, afb...@gmail.com <mailto:afb...@gmail.com> 608 658-1890 cell 608 261-5738 wk
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