=head1 NAME
-perlfaq3 - Programming Tools ($Revision: 1.29 $, $Date: 1998/08/05 11:57:04 $)
+perlfaq3 - Programming Tools ($Revision: 1.33 $, $Date: 1998/12/29 20:12:12 $)
=head1 DESCRIPTION
for: 4 secs ( 3.97 usr 0.01 sys = 3.98 cpu)
map: 6 secs ( 4.97 usr 0.00 sys = 4.97 cpu)
+Be aware that a good benchmark is very hard to write. It only tests the
+data you give it, and really proves little about differing complexities
+of contrasting algorithms.
+
=head2 How do I cross-reference my Perl programs?
The B::Xref module, shipped with the new, alpha-release Perl compiler
write it will help prevent bugs. Your editor can and should help you
with this. The perl-mode for emacs can provide a remarkable amount of
help with most (but not all) code, and even less programmable editors
-can provide significant assistance.
+can provide significant assistance. Tom swears by the following
+settings in vi and its clones:
+
+ set ai sw=4
+ map ^O {^M}^[O^T
-If you are used to using I<vgrind> program for printing out nice code
+Now put that in your F<.exrc> file (replacing the caret characters
+with control characters) and away you go. In insert mode, ^T is
+for indenting, ^D is for undenting, and ^O is for blockdenting --
+as it were. If you haven't used the last one, you're missing
+a lot. A more complete example, with comments, can be found at
+http://www.perl.com/CPAN-local/authors/id/TOMC/scripts/toms.exrc.gz
+
+If you are used to using the I<vgrind> program for printing out nice code
to a laser printer, you can take a stab at this using
http://www.perl.com/CPAN/doc/misc/tips/working.vgrind.entry, but the
results are not particularly satisfying for sophisticated code.
-=head2 Is there a ctags for Perl?
+The a2ps at http://www.infres.enst.fr/~demaille/a2ps/ does lots of things
+related to generating nicely printed output of documents.
+
+=head2 Is there a etags/ctags for perl?
-There's a simple one at
+With respect to the source code for the Perl interpreter, yes.
+There has been support for etags in the source for a long time.
+Ctags was introduced in v5.005_54 (and probably 5.005_03).
+After building perl, type 'make etags' or 'make ctags' and both
+sets of tag files will be built.
+
+Now, if you're looking to build a tag file for perl code, then there's
+a simple one at
http://www.perl.com/CPAN/authors/id/TOMC/scripts/ptags.gz which may do
-the trick.
+the trick. And if not, it's easy to hack into what you want.
+
+=head2 Is there an IDE or Windows Perl Editor?
+
+If you're on Unix, you already have an IDE -- Unix itself.
+You just have to learn the toolbox. If you're not, then you
+probably don't have a toolbox, so may need something else.
+
+PerlBuilder (XXX URL to follow) is an integrated development
+environment for Windows that supports Perl development. Perl programs
+are just plain text, though, so you could download emacs for Windows
+(XXX) or vim for win32 (http://www.cs.vu.nl/~tmgil/vi.html). If
+you're transferring Windows files to Unix, be sure to transfer in
+ASCII mode so the ends of lines are appropriately converted.
=head2 Where can I get Perl macros for vi?
For a complete version of Tom Christiansen's vi configuration file,
-see http://www.perl.com/CPAN/authors/Tom_Christiansen/scripts/toms.exrc,
+see http://www.perl.com/CPAN/authors/Tom_Christiansen/scripts/toms.exrc.gz,
the standard benchmark file for vi emulators. This runs best with nvi,
the current version of vi out of Berkeley, which incidentally can be built
with an embedded Perl interpreter -- see http://www.perl.com/CPAN/src/misc.
Note that the perl-mode of emacs will have fits with C<"main'foo">
(single quote), and mess up the indentation and hilighting. You
-should be using C<"main::foo"> in new Perl code anyway, so this
+are probably using C<"main::foo"> in new Perl code anyway, so this
shouldn't be an issue.
=head2 How can I use curses with Perl?
When it comes to time-space tradeoffs, Perl nearly always prefers to
throw memory at a problem. Scalars in Perl use more memory than
-strings in C, arrays take more that, and hashes use even more. While
+strings in C, arrays take more than that, and hashes use even more. While
there's still a lot to be done, recent releases have been addressing
these issues. For example, as of 5.004, duplicate hash keys are
shared amongst all hashes using them, so require no reallocation.
You can't. On most operating systems, memory allocated to a program
can never be returned to the system. That's why long-running programs
-sometimes re-exec themselves. Some operating systems (notably, FreeBSD)
-allegedly reclaim large chunks of memory that is no longer used, but
-it doesn't appear to happen with Perl (yet). The Mac appears to be the
-only platform that will reliably (albeit, slowly) return memory to the OS.
+sometimes re-exec themselves. Some operating systems (notably,
+FreeBSD and Linux) allegedly reclaim large chunks of memory that is no
+longer used, but it doesn't appear to happen with Perl (yet). The Mac
+appears to be the only platform that will reliably (albeit, slowly)
+return memory to the OS.
+
+We've had reports that on Linux (Redhat 5.1) on Intel, C<undef
+$scalar> will return memory to the system, while on Solaris 2.6 it
+won't. In general, try it yourself and see.
However, judicious use of my() on your variables will help make sure
that they go out of scope so that Perl can free up their storage for
anything a module written in C can. For more on mod_perl, see
http://perl.apache.org/
-With the FCGI module (from CPAN), a Perl executable compiled with sfio
-(see the F<INSTALL> file in the distribution) and the mod_fastcgi
+With the FCGI module (from CPAN) and the mod_fastcgi
module (available from http://www.fastcgi.com/) each of your perl
scripts becomes a permanent CGI daemon process.
See http://www.perl.com/CPAN/modules/by-category/15_World_Wide_Web_HTML_HTTP_CGI/ .
-A non-free, commerical product, ``The Velocity Engine for Perl'',
+A non-free, commercial product, ``The Velocity Engine for Perl'',
(http://www.binevolve.com/ or http://www.binevolve.com/bine/vep) might
also be worth looking at. It will allow you to increase the performance
of your perl scripts, upto 25 times faster than normal CGI perl by
instead of fixing them, is little security indeed.
You can try using encryption via source filters (Filter::* from CPAN),
-but crackers might be able to decrypt it. You can try using the byte
-code compiler and interpreter described below, but crackers might be
-able to de-compile it. You can try using the native-code compiler
-described below, but crackers might be able to disassemble it. These
-pose varying degrees of difficulty to people wanting to get at your
-code, but none can definitively conceal it (this is true of every
+but any decent programmer will be able to decrypt it. You can try using
+the byte code compiler and interpreter described below, but the curious
+might still be able to de-compile it. You can try using the native-code
+compiler described below, but crackers might be able to disassemble it.
+These pose varying degrees of difficulty to people wanting to get at
+your code, but none can definitively conceal it (this is true of every
language, not just Perl).
If you're concerned about people profiting from your code, then the
you use a shared I<libperl.so>), you'll probably want a complete
Perl install anyway.
+=head2 How can I compile Perl into Java?
+
+You can't. Not yet, anyway. You can integrate Java and Perl with the
+Perl Resource Kit from O'Reilly and Associates. See
+http://www.oreilly.com/catalog/prkunix/ for more information.
+The Java interface will be supported in the core 5.006 release
+of Perl.
+
=head2 How can I get C<#!perl> to work on [MS-DOS,NT,...]?
For OS/2 just use
The Win95/NT installation, when using the ActiveState port of Perl,
will modify the Registry to associate the C<.pl> extension with the
-perl interpreter. If you install another port (Gurusaramy Sarathy's
-is the recommended Win95/NT port), or (eventually) build your own
-Win95/NT Perl using WinGCC, then you'll have to modify the Registry
-yourself.
-
-Macintosh perl scripts will have the the appropriate Creator and
+perl interpreter. If you install another port (Gurusamy Sarathy's is
+the recommended Win95/NT port), or (eventually) build your own
+Win95/NT Perl using a Windows port of gcc (e.g., with cygwin32 or
+mingw32), then you'll have to modify the Registry yourself. In
+addition to associating C<.pl> with the interpreter, NT people can
+use: C<SET PATHEXT=%PATHEXT%;.PL> to let them run the program
+C<install-linux.pl> merely by typing C<install-linux>.
+
+Macintosh perl scripts will have the appropriate Creator and
Type, so that double-clicking them will invoke the perl application.
I<IMPORTANT!>: Whatever you do, PLEASE don't get frustrated, and just
quoting variants, except that it makes free use of the Mac's non-ASCII
characters as control characters.
+Using qq(), q(), and qx(), instead of "double quotes", 'single
+quotes', and `backticks`, may make one-liners easier to write.
+
There is no general solution to all of this. It is a mess, pure and
simple. Sucks to be away from Unix, huh? :-)
=head1 AUTHOR AND COPYRIGHT
-Copyright (c) 1997, 1998 Tom Christiansen and Nathan Torkington.
+Copyright (c) 1997-1999 Tom Christiansen and Nathan Torkington.
All rights reserved.
When included as an integrated part of the Standard Distribution
-of Perl or of its documentation (printed or otherwise), this works is
+of Perl or of its documentation (printed or otherwise), this work is
covered under Perl's Artistic Licence. For separate distributions of
all or part of this FAQ outside of that, see L<perlfaq>.
derivatives thereof in your own programs for fun or for profit as you
see fit. A simple comment in the code giving credit to the FAQ would
be courteous but is not required.
+
projects / p5sagit/p5-mst-13.2.git / blobdiff