quoted, the type of quotes you use determines the treatment of the
text, just as in regular quoting. An unquoted identifier works like
double quotes. There must be no space between the C<< << >> and
-the identifier. (If you put a space it will be treated as a null
-identifier, which is valid, and matches the first empty line.) The
-terminating string must appear by itself (unquoted and with no
-surrounding whitespace) on the terminating line.
+the identifier, unless the identifier is quoted. (If you put a space it
+will be treated as a null identifier, which is valid, and matches the first
+empty line.) The terminating string must appear by itself (unquoted and
+with no surrounding whitespace) on the terminating line.
print <<EOF;
The price is $Price.
EOF
- print <<"EOF"; # same as above
+ print << "EOF"; # same as above
The price is $Price.
EOF
- print <<`EOC`; # execute commands
+ print << `EOC`; # execute commands
echo hi there
echo lo there
EOC
I said bar.
bar
- myfunc(<<"THIS", 23, <<'THAT');
+ myfunc(<< "THIS", 23, <<'THAT');
Here's a line
or two.
THIS
the other
E
+If the terminating identifier is on the last line of the program, you
+must be sure there is a newline after it; otherwise, Perl will give the
+warning B<Can't find string terminator "END" anywhere before EOF...>.
+
+Additionally, the quoting rules for the identifier are not related to
+Perl's quoting rules -- C<q()>, C<qq()>, and the like are not supported
+in place of C<''> and C<"">, and the only interpolation is for backslashing
+the quoting character:
+
+ print << "abc\"def";
+ testing...
+ abc"def
+
+Finally, quoted strings cannot span multiple lines. The general rule is
+that the identifier must be a string literal. Stick with that, and you
+should be safe.
+
=head2 List value constructors
List values are denoted by separating individual values by commas