for completeness:
> Of course, that doesn't test if the metachars make sense as a regex
let's Perl parse Perl =)
$ perl -ple ' $_ = eval "sub { /$_/ }" ? "OK\n" : "$@" '
a
OK
a(
Unmatched ( in regex; marked by <-- HERE in m/a( <-- HERE / at (eval 2
+) line 1, <> line 2.
a[
Unmatched [ in regex; marked by <-- HERE in m/a[ <-- HERE / at (eval 3
+) line 1, <> line 3.
a()
OK
UPDATE
unfortunately not always correct:
$ perl -ple ' $_ = eval "sub { /$_/ }" ? "OK\n" : "$@" '
a[$]
OK
but
$ perl -e ' "abc" =~ /a[$]/ '
Unmatched [ in regex; marked by <-- HERE in m/a[ <-- HERE 5.010000/ at
+ -e line 1.
UPDATE
interesting, this happens because it's a run-time error ... (why?)
$ perl -e 'sub {"aaa" =~ /a[$]/}'
$ perl -e '"aaa" =~ /a[$]/'
Unmatched [ in regex; marked by <-- HERE in m/a[ <-- HERE 5.010000/ at
+ -e line 1.
$ perl -ce '"aaa" =~ /a[$]/'
-e syntax OK
looks like a parser problem for me!
UPDATE
variable interpolation is part of the problem,
a[$]
is a valid pattern, as long as it's not interpolated:
perl -E 'say q(a$) =~ q(a[$]) '
1
UPDATE
this is very reliable
perl -ple ' $_ = eval "sub { 'a' =~ q\0$_\0 }" ? "OK\n" : "$@" '
to avoid problems with \0-delim consider using here-docs instead, or even a pack/unpack combination
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.