=item B<Use a UNIX program from Perl?>
-Read about backquotes and L<perlfunc/system> and L<perlfunc/exec>.
+Read about back-quotes and about C<system> and C<exec> in L<perlfunc>.
=item B<Use Perl from Perl?>
-Read about L<perlfunc/do> and L<perlfunc/eval> and L<perlmod/use>
-and L<perlmod/require>.
+Read about C<do> and C<eval> in L<perlfunc/do> and L<perlfunc/eval> and C<use>
+and C<require> in L<perlmod> and L<perlfunc/require>, L<perlfunc/use>.
=item B<Use C from C?>
Note that we do not use the C<env> pointer here or in any of the
following examples.
-Normally handed to C<perl_parse> as it's final argument,
+Normally handed to C<perl_parse> as its final argument,
we hand it a B<NULL> instead, in which case the current environment
is used.
=head2 Evaluating a Perl statement from your C program
NOTE: This section, and the next, employ some very brittle techniques
-for evaluting strings of Perl code. Perl 5.002 contains some nifty
+for evaluating strings of Perl code. Perl 5.002 contains some nifty
features that enable A Better Way (such as with L<perlguts/perl_eval_sv>).
Look for updates to this document soon.
Arguably, this is the only routine you'll ever need to execute
snippets of Perl code from within your C program. Your string can be
as long as you wish; it can contain multiple statements; it can
-use L<perlmod/require> or L<perlfunc/do> to include external Perl
+use L<perlfunc/require> or L<perlfunc/do> to include external Perl
files.
Our I<perl_eval()> lets us evaluate individual Perl strings, and then
char match(char *string, char *pattern);
-Given a string and a pattern (e.g. "m/clasp/" or "/\b\w*\b/", which in
+Given a string and a pattern (e.g., "m/clasp/" or "/\b\w*\b/", which in
your program might be represented as C<"/\\b\\w*\\b/">),
returns 1 if the string matches the pattern and 0 otherwise.
int substitute(char *string[], char *pattern);
-Given a pointer to a string and an "=~" operation (e.g. "s/bob/robert/g" or
+Given a pointer to a string and an "=~" operation (e.g., "s/bob/robert/g" or
"tr[A-Z][a-z]"), modifies the string according to the operation,
returning the number of substitutions made.
Once you've understood those, embedding Perl in C is easy.
-Since C has no built-in function for integer exponentiation, let's
+Because C has no built-in function for integer exponentiation, let's
make Perl's ** operator available to it (this is less useful than it
-sounds, since Perl implements ** with C's I<pow()> function). First
+sounds, because Perl implements ** with C's I<pow()> function). First
I'll create a stub exponentiation function in I<power.pl>:
sub expo {
part; leave that to the I<xsubpp> and extension authors. If your
extension is dynamically loaded, DynaLoader creates I<Module::bootstrap()>
for you on the fly. In fact, if you have a working DynaLoader then there
-is rarely any need to statically link in any other extensions.
+is rarely any need to link in any other extensions statically.
Once you have this code, slap it into the second argument of I<perl_parse()>:
=head1 MORAL
You can sometimes I<write faster code> in C, but
-you can always I<write code faster> in Perl. Since you can use
+you can always I<write code faster> in Perl. Because you can use
each from the other, combine them as you wish.
projects / p5sagit/p5-mst-13.2.git / blobdiff