Detpyo.

[p5sagit/p5-mst-13.2.git] / pod / perlop.pod

diff --git a/pod/perlop.pod b/pod/perlop.pod
index b317bde..69c8c69 100644 (file)
--- a/pod/perlop.pod
+++ b/pod/perlop.pod
@@ -119,7 +119,7 @@ you increment a variable that is numeric, or that has ever been used in
 a numeric context, you get a normal increment.  If, however, the
 variable has been used in only string contexts since it was set, and
 has a value that is not the empty string and matches the pattern
-C</^[a-zA-Z]*[0-9]*$/>, the increment is done as a string, preserving each
+C</^[a-zA-Z]*[0-9]*\z/>, the increment is done as a string, preserving each
 character within its range, with carry:
 
     print ++($foo = '99');     # prints '100'
@@ -710,7 +710,7 @@ on a Mac, these are reversed, and on systems without line terminator,
 printing C<"\n"> may emit no actual data.  In general, use C<"\n"> when
 you mean a "newline" for your system, but use the literal ASCII when you
 need an exact character.  For example, most networking protocols expect
-and prefer a CR+LF (C<"\012\015"> or C<"\cJ\cM">) for line terminators,
+and prefer a CR+LF (C<"\015\012"> or C<"\cM\cJ">) for line terminators,
 and although they often accept just C<"\012">, they seldom tolerate just
 C<"\015">.  If you get in the habit of using C<"\n"> for networking,
 you may be burned some day.
@@ -851,9 +851,11 @@ string also resets the search position.
 
 You can intermix C<m//g> matches with C<m/\G.../g>, where C<\G> is a
 zero-width assertion that matches the exact position where the previous
-C<m//g>, if any, left off.  The C<\G> assertion is not supported without
-the C</g> modifier.  (Currently, without C</g>, C<\G> behaves just like
-C<\A>, but that's accidental and may change in the future.)
+C<m//g>, if any, left off.  Without the C</g> modifier, the C<\G> assertion
+still anchors at pos(), but the match is of course only attempted once.
+Using C<\G> without C</g> on a target string that has not previously had a
+C</g> match applied to it is the same as using the C<\A> assertion to match
+the beginning of the string.
 
 Examples:
 
@@ -861,7 +863,7 @@ Examples:
     ($one,$five,$fifteen) = (`uptime` =~ /(\d+\.\d+)/g);
 
     # scalar context
-    $/ = ""; $* = 1;  # $* deprecated in modern perls
+    $/ = "";
     while (defined($paragraph = <>)) {
        while ($paragraph =~ /[a-z]['")]*[.!?]+['")]*\s/g) {
            $sentences++;
@@ -879,6 +881,7 @@ Examples:
         print "3: '";
         print $1 while /(p)/gc; print "', pos=", pos, "\n";
     }
+    print "Final: '$1', pos=",pos,"\n" if /\G(.)/;
 
 The last example should print:
 
@@ -888,6 +891,13 @@ The last example should print:
     1: '', pos=7
     2: 'q', pos=8
     3: '', pos=8
+    Final: 'q', pos=8
+
+Notice that the final match matched C<q> instead of C<p>, which a match
+without the C<\G> anchor would have done. Also note that the final match
+did not update C<pos> -- C<pos> is only updated on a C</g> match. If the
+final match did indeed match C<p>, it's a good bet that you're running an
+older (pre-5.6.0) Perl.
 
 A useful idiom for C<lex>-like scanners is C</\G.../gc>.  You can
 combine several regexps like this to process a string part-by-part,
@@ -941,7 +951,7 @@ A double-quoted, interpolated string.
 
 =item qr/STRING/imosx
 
-This operators quotes--and compiles--its I<STRING> as a regular
+This operator quotes (and possibly compiles) its I<STRING> as a regular
 expression.  I<STRING> is interpolated the same way as I<PATTERN>
 in C<m/PATTERN/>.  If "'" is used as the delimiter, no interpolation
 is done.  Returns a Perl value which may be used instead of the