X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=pod%2Fperlmod.pod;h=1174e7632b0f659f90d6efc26d30aee7984ac711;hb=5695b28edc67a3f45e8a0f25755d07afef3660ac;hp=731b25e67c0f4dc9af76f3c29512e5d8ff8dc54b;hpb=c36e9b625651d91621c34cd98beebb657f39c38d;p=p5sagit%2Fp5-mst-13.2.git diff --git a/pod/perlmod.pod b/pod/perlmod.pod index 731b25e..1174e76 100644 --- a/pod/perlmod.pod +++ b/pod/perlmod.pod @@ -13,11 +13,11 @@ Perl. The package statement declares the compilation unit as being in the given namespace. The scope of the package declaration is from the declaration itself through the end of the enclosing block (the same scope as the local() operator). All further unqualified dynamic identifiers -will be in this namespace. A package statement only affects dynamic +will be in this namespace. A package statement affects only dynamic variables--including those you've used local() on--but I lexical variables created with my(). Typically it would be the first declaration in a file to be included by the C or C operator. You can -switch into a package in more than one place; it merely influences which +switch into a package in more than one place; it influences merely which symbol table is used by the compiler for the rest of that block. You can refer to variables and filehandles in other packages by prefixing the identifier with the package name and a double colon: @@ -39,10 +39,10 @@ It would treat package C as a totally separate global package. Only identifiers starting with letters (or underscore) are stored in a package's symbol table. All other symbols are kept in package C
, including all of the punctuation variables like $_. In addition, the -identifiers STDIN, STDOUT, STDERR, ARGV, ARGVOUT, ENV, INC and SIG are +identifiers STDIN, STDOUT, STDERR, ARGV, ARGVOUT, ENV, INC, and SIG are forced to be in package C
, even when used for other purposes than their built-in one. Note also that, if you have a package called C, -C or C, then you can't use the qualified form of an identifier +C, or C, then you can't use the qualified form of an identifier because it will be interpreted instead as a pattern match, a substitution, or a translation. @@ -62,23 +62,23 @@ temporarily switches back to the C
package to evaluate various expressions in the context of the C
package (or wherever you came from). See L. -See L for other scoping issues related to my() and local(), +See L for other scoping issues related to my() and local(), or L regarding closures. =head2 Symbol Tables -The symbol table for a package happens to be stored in the associative -array of that name appended with two colons. The main symbol table's -name is thus C<%main::>, or C<%::> for short. Likewise symbol table for -the nested package mentioned earlier is named C<%OUTER::INNER::>. +The symbol table for a package happens to be stored in the hash of that +name with two colons appended. The main symbol table's name is thus +C<%main::>, or C<%::> for short. Likewise symbol table for the nested +package mentioned earlier is named C<%OUTER::INNER::>. -The value in each entry of the associative array is what you are referring -to when you use the C<*name> typeglob notation. In fact, the following -have the same effect, though the first is more efficient because it does -the symbol table lookups at compile time: +The value in each entry of the hash is what you are referring to when you +use the C<*name> typeglob notation. In fact, the following have the same +effect, though the first is more efficient because it does the symbol +table lookups at compile time: - local(*main::foo) = *main::bar; local($main::{'foo'}) = - $main::{'bar'}; + local(*main::foo) = *main::bar; + local($main::{'foo'}) = $main::{'bar'}; You can use this to print out all the variables in a package, for instance. Here is F from the Perl library: @@ -119,9 +119,9 @@ Assignment to a typeglob performs an aliasing operation, i.e., *dick = *richard; -causes variables, subroutines and file handles accessible via the +causes variables, subroutines, and file handles accessible via the identifier C to also be accessible via the identifier C. If -you only want to alias a particular variable or subroutine, you can +you want to alias only a particular variable or subroutine, you can assign a reference instead: *dick = \$richard; @@ -140,10 +140,10 @@ thing. # now use %hashsym normally, and you # will affect the caller's %another_hash my %nhash = (); # do what you want - return \%nhash; + return \%nhash; } -On return, the reference wil overwrite the hash slot in the +On return, the reference will overwrite the hash slot in the symbol table specified by the *some_hash typeglob. This is a somewhat tricky way of passing around references cheaply when you won't want to have to remember to dereference variables @@ -155,6 +155,25 @@ Another use of symbol tables is for making "constant" scalars. Now you cannot alter $PI, which is probably a good thing all in all. +You can say C<*foo{PACKAGE}> and C<*foo{NAME}> to find out what name and +package the *foo symbol table entry comes from. This may be useful +in a subroutine which is passed typeglobs as arguments + + sub identify_typeglob { + my $glob = shift; + print 'You gave me ', *{$glob}{PACKAGE}, '::', *{$glob}{NAME}, "\n"; + } + identify_typeglob *foo; + identify_typeglob *bar::baz; + +This prints + + You gave me main::foo + You gave me bar::baz + +The *foo{THING} notation can also be used to obtain references to the +individual elements of *foo, see L. + =head2 Package Constructors and Destructors There are two special subroutine definitions that function as package @@ -178,7 +197,7 @@ order of definition; that is: last in, first out (LIFO). Inside an C subroutine C<$?> contains the value that the script is going to pass to C. You can modify C<$?> to change the exit -value of the script. Beware of changing C<$?> by accident (eg, by +value of the script. Beware of changing C<$?> by accident (e.g.,, by running something via C). Note that when you use the B<-n> and B<-p> switches to Perl, C @@ -189,7 +208,7 @@ and C work just as they do in B, as a degenerate case. There is no special class syntax in Perl, but a package may function as a class if it provides subroutines that function as methods. Such a package may also derive some of its methods from another class package -by listing the other package name in its @ISA array. +by listing the other package name in its @ISA array. For more on this, see L. @@ -203,18 +222,70 @@ definition and make its semantics available implicitly through method calls on the class and its objects, without explicit exportation of any symbols. Or it can do a little of both. -For example, to start a normal module called Fred, create -a file called Fred.pm and put this at the start of it: +For example, to start a normal module called Some::Module, create +a file called Some/Module.pm and start with this template: + + package Some::Module; # assumes Some/Module.pm + + use strict; + + BEGIN { + use Exporter (); + use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS); + + # set the version for version checking + $VERSION = 1.00; + # if using RCS/CVS, this may be preferred + $VERSION = do { my @r = (q$Revision: 2.21 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r }; # must be all one line, for MakeMaker + + @ISA = qw(Exporter); + @EXPORT = qw(&func1 &func2 &func4); + %EXPORT_TAGS = ( ); # eg: TAG => [ qw!name1 name2! ], + + # your exported package globals go here, + # as well as any optionally exported functions + @EXPORT_OK = qw($Var1 %Hashit &func3); + } + use vars @EXPORT_OK; + + # non-exported package globals go here + use vars qw(@more $stuff); + + # initalize package globals, first exported ones + $Var1 = ''; + %Hashit = (); + + # then the others (which are still accessible as $Some::Module::stuff) + $stuff = ''; + @more = (); + + # all file-scoped lexicals must be created before + # the functions below that use them. + + # file-private lexicals go here + my $priv_var = ''; + my %secret_hash = (); - package Fred; - use Exporter (); - @ISA = qw(Exporter); - @EXPORT = qw(func1 func2); - @EXPORT_OK = qw($sally @listabob %harry func3); + # here's a file-private function as a closure, + # callable as &$priv_func; it cannot be prototyped. + my $priv_func = sub { + # stuff goes here. + }; + + # make all your functions, whether exported or not; + # remember to put something interesting in the {} stubs + sub func1 {} # no prototype + sub func2() {} # proto'd void + sub func3($$) {} # proto'd to 2 scalars + + # this one isn't exported, but could be called! + sub func4(\%) {} # proto'd to 1 hash ref + + END { } # module clean-up code here (global destructor) Then go on to declare and use your variables in functions without any qualifications. -See L and the I for details on +See L and the I for details on mechanics and style issues in module creation. Perl modules are included into your program by saying @@ -259,7 +330,7 @@ instead of C. With require you can get into this problem: require Cwd; # make Cwd:: accessible $here = Cwd::getcwd(); - use Cwd; # import names from Cwd:: + use Cwd; # import names from Cwd:: $here = getcwd(); require Cwd; # make Cwd:: accessible @@ -280,7 +351,7 @@ the module. If so, these will be entirely transparent to the user of the module. It is the responsibility of the F<.pm> file to load (or arrange to autoload) any additional functionality. The POSIX module happens to do both dynamic loading and autoloading, but the user can -just say C to get it all. +say just C to get it all. For more information on writing extension modules, see L and L. @@ -296,73 +367,98 @@ because it has a shotgun. The module and its user have a contract, part of which is common law, and part of which is "written". Part of the common law contract is that a module doesn't pollute any namespace it wasn't asked to. The -written contract for the module (AKA documentation) may make other +written contract for the module (A.K.A. documentation) may make other provisions. But then you know when you C that you're redefining the world and willing to take the consequences. =head1 THE PERL MODULE LIBRARY -A number of modules are included the the Perl distribution. These are -described below, and all end in F<.pm>. You may also discover files in +A number of modules are included the Perl distribution. These are +described below, and all end in F<.pm>. You may also discover files in the library directory that end in either F<.pl> or F<.ph>. These are old libraries supplied so that old programs that use them still run. The F<.pl> files will all eventually be converted into standard modules, and the F<.ph> files made by B will probably end up as extension modules made by B. (Some F<.ph> values may already be available through the POSIX module.) The B file in the distribution may help in your -conversion, but it's just a mechanical process, so is far from bulletproof. +conversion, but it's just a mechanical process and therefore far from +bulletproof. =head2 Pragmatic Modules They work somewhat like pragmas in that they tend to affect the compilation of -your program, and thus will usually only work well when used within a -C, or C. These are locally scoped, so an inner BLOCK -may countermand any of these by saying +your program, and thus will usually work well only when used within a +C, or C. Most of these are locally scoped, so an inner BLOCK +may countermand any of these by saying: no integer; no strict 'refs'; which lasts until the end of that BLOCK. -The following programs are defined (and have their own documentation). +Unlike the pragmas that effect the C<$^H> hints variable, the C and C declarations are not BLOCK-scoped. They allow +you to pre-declare a variables or subroutines within a particular +I rather than just a block. Such declarations are effective +for the entire file for which they were declared. You cannot rescind +them with C or C. + +The following pragmas are defined (and have their own documentation). =over 12 +=item blib + +manipulate @INC at compile time to use MakeMaker's uninstalled version +of a package + =item diagnostics -Pragma to produce enhanced diagnostics +force verbose warning diagnostics =item integer -Pragma to compute arithmetic in integer instead of double +compute arithmetic in integer instead of double =item less -Pragma to request less of something from the compiler +request less of something from the compiler + +=item lib + +manipulate @INC at compile time + +=item locale + +use or ignore current locale for built-in operations (see L) =item ops -Pragma to restrict use of unsafe opcodes +restrict named opcodes when compiling or running Perl code =item overload -Pragma for overloading operators +overload basic Perl operations =item sigtrap -Pragma to enable stack backtrace on unexpected signals +enable simple signal handling =item strict -Pragma to restrict unsafe constructs +restrict unsafe constructs =item subs -Pragma to predeclare sub names +pre-declare sub names + +=item vmsish + +adopt certain VMS-specific behaviors =item vars -Pragma to predeclare global symbols +pre-declare global variable names =back @@ -390,13 +486,29 @@ split a package for autoloading benchmark running times of code +=item CPAN + +interface to Comprehensive Perl Archive Network + +=item CPAN::FirstTime + +create a CPAN configuration file + +=item CPAN::Nox + +run CPAN while avoiding compiled extensions + =item Carp warn of errors (from perspective of caller) +=item Class::Template + +struct/member template builder + =item Config -access Perl configuration option +access Perl configuration information =item Cwd @@ -404,32 +516,56 @@ get pathname of current working directory =item DB_File -Perl access to Berkeley DB +access to Berkeley DB =item Devel::SelfStubber generate stubs for a SelfLoading module +=item DirHandle + +supply object methods for directory handles + =item DynaLoader -Dynamically load C libraries into Perl code +dynamically load C libraries into Perl code =item English -use nice English (or B) names for ugly punctuation variables +use nice English (or awk) names for ugly punctuation variables =item Env -perl module that imports environment variables +import environment variables =item Exporter -provide import/export controls for Perl modules +implements default import method for modules + +=item ExtUtils::Embed + +utilities for embedding Perl in C/C++ applications + +=item ExtUtils::Install + +install files from here to there =item ExtUtils::Liblist determine libraries to use and how to use them +=item ExtUtils::MM_OS2 + +methods to override UN*X behaviour in ExtUtils::MakeMaker + +=item ExtUtils::MM_Unix + +methods used by ExtUtils::MakeMaker + +=item ExtUtils::MM_VMS + +methods to override UN*X behaviour in ExtUtils::MakeMaker + =item ExtUtils::MakeMaker create an extension Makefile @@ -442,9 +578,13 @@ utilities to write and check a MANIFEST file make a bootstrap file for use by DynaLoader -=item ExtUtils::Miniperl +=item ExtUtils::Mksymlists -!!!GOOD QUESTION!!! +write linker options files for dynamic extension + +=item ExtUtils::testlib + +add blib/* directories to @INC =item Fcntl @@ -452,64 +592,196 @@ load the C Fcntl.h defines =item File::Basename -parse file specifications +split a pathname into pieces =item File::CheckTree run many filetest checks on a tree +=item File::Compare + +compare files or filehandles + +=item File::Copy + +copy files or filehandles + =item File::Find traverse a file tree +=item File::Path + +create or remove a series of directories + +=item File::stat + +by-name interface to Perl's built-in stat() functions + +=item FileCache + +keep more files open than the system permits + =item FileHandle supply object methods for filehandles -=item File::Path +=item FindBin -create or remove a series of directories +locate directory of original perl script + +=item GDBM_File + +access to the gdbm library =item Getopt::Long -extended getopt processing +extended processing of command line options =item Getopt::Std -Process single-character switches with switch clustering +process single-character switches with switch clustering =item I18N::Collate compare 8-bit scalar data according to the current locale +=item IO + +load various IO modules + +=item IO::File + +supply object methods for filehandles + +=item IO::Handle + +supply object methods for I/O handles + +=item IO::Pipe + +supply object methods for pipes + +=item IO::Seekable + +supply seek based methods for I/O objects + +=item IO::Select + +OO interface to the select system call + +=item IO::Socket + +object interface to socket communications + =item IPC::Open2 -a process for both reading and writing +open a process for both reading and writing =item IPC::Open3 open a process for reading, writing, and error handling +=item Math::BigFloat + +arbitrary length float math package + +=item Math::BigInt + +arbitrary size integer math package + +=item Math::Complex + +complex numbers and associated mathematical functions + +=item NDBM_File + +tied access to ndbm files + =item Net::Ping -check a host for upness +Hello, anybody home? + +=item Net::hostent + +by-name interface to Perl's built-in gethost*() functions + +=item Net::netent + +by-name interface to Perl's built-in getnet*() functions + +=item Net::protoent + +by-name interface to Perl's built-in getproto*() functions + +=item Net::servent + +by-name interface to Perl's built-in getserv*() functions + +=item Opcode + +disable named opcodes when compiling or running perl code + +=item Pod::Text + +convert POD data to formatted ASCII text =item POSIX -Perl interface to IEEE Std 1003.1 +interface to IEEE Standard 1003.1 + +=item SDBM_File + +tied access to sdbm files + +=item Safe + +compile and execute code in restricted compartments + +=item Search::Dict + +search for key in dictionary file + +=item SelectSaver + +save and restore selected file handle =item SelfLoader load functions only on demand -=item Safe +=item Shell -Creation controlled compartments in which perl code can be evaluated. +run shell commands transparently within perl =item Socket load the C socket.h defines and structure manipulators +=item Symbol + +manipulate Perl symbols and their names + +=item Sys::Hostname + +try every conceivable way to get hostname + +=item Sys::Syslog + +interface to the UNIX syslog(3) calls + +=item Term::Cap + +termcap interface + +=item Term::Complete + +word completion module + +=item Term::ReadLine + +interface to various C packages + =item Test::Harness run perl standard test scripts with statistics @@ -518,6 +790,66 @@ run perl standard test scripts with statistics create an abbreviation table from a list +=item Text::ParseWords + +parse text into an array of tokens + +=item Text::Soundex + +implementation of the Soundex Algorithm as described by Knuth + +=item Text::Tabs + +expand and unexpand tabs per the unix expand(1) and unexpand(1) + +=item Text::Wrap + +line wrapping to form simple paragraphs + +=item Tie::Hash + +base class definitions for tied hashes + +=item Tie::RefHash + +base class definitions for tied hashes with references as keys + +=item Tie::Scalar + +base class definitions for tied scalars + +=item Tie::SubstrHash + +fixed-table-size, fixed-key-length hashing + +=item Time::Local + +efficiently compute time from local and GMT time + +=item Time::gmtime + +by-name interface to Perl's built-in gmtime() function + +=item Time::localtime + +by-name interface to Perl's built-in localtime() function + +=item Time::tm + +internal object used by Time::gmtime and Time::localtime + +=item UNIVERSAL + +base class for ALL classes (blessed references) + +=item User::grent + +by-name interface to Perl's built-in getgr*() functions + +=item User::pwent + +by-name interface to Perl's built-in getpw*() functions + =back To find out I the modules installed on your system, including @@ -530,12 +862,13 @@ your system man(1) command. If that fails, try the I program. =head2 Extension Modules -Extension modules are written in C (or a mix of Perl and C) and get +Extension modules are written in C (or a mix of Perl and C) and may be +statically linked or in general are dynamically loaded into Perl if and when you need them. Supported extension modules include the Socket, Fcntl, and POSIX modules. Many popular C extension modules do not come bundled (at least, not -completely) due to their size, volatility, or simply lack of time for +completely) due to their sizes, volatility, or simply lack of time for adequate testing and configuration across the multitude of platforms on which Perl was beta-tested. You are encouraged to look for them in archie(1L), the Perl FAQ or Meta-FAQ, the WWW page, and even with their @@ -545,13 +878,13 @@ disposition. =head1 CPAN CPAN stands for the Comprehensive Perl Archive Network. This is a globally -replicated collection of all known Perl materials, including hundreds +replicated collection of all known Perl materials, including hundreds of unbundled modules. Here are the major categories of modules: =over =item * -Language Extensions and Documentation Tools +Language Extensions and Documentation Tools =item * Development Support @@ -578,16 +911,16 @@ Interfaces to / Emulations of Other Programming Languages File Names, File Systems and File Locking (see also File Handles) =item * -String Processing, Language Text Processing, Parsing and Searching +String Processing, Language Text Processing, Parsing, and Searching =item * -Option, Argument, Parameter and Configuration File Processing +Option, Argument, Parameter, and Configuration File Processing =item * Internationalization and Locale =item * -Authentication, Security and Encryption +Authentication, Security, and Encryption =item * World Wide Web, HTML, HTTP, CGI, MIME @@ -599,7 +932,7 @@ Server and Daemon Utilities Archiving and Compression =item * -Images, Pixmap and Bitmap Manipulation, Drawing and Graphing +Images, Pixmap and Bitmap Manipulation, Drawing, and Graphing =item * Mail and Usenet News @@ -621,82 +954,98 @@ You should try to choose one close to you: =over =item * -ftp://ftp.sterling.com/programming/languages/perl/ - -=item * -ftp://ftp.sedl.org/pub/mirrors/CPAN/ - -=item * -ftp://ftp.uoknor.edu/mirrors/CPAN/ - -=item * -ftp://ftp.delphi.com/pub/mirrors/packages/perl/CPAN/ - -=item * -ftp://uiarchive.cso.uiuc.edu/pub/lang/perl/CPAN/ - -=item * -ftp://ftp.cis.ufl.edu/pub/perl/CPAN/ - -=item * -ftp://ftp.switch.ch/mirror/CPAN/ - -=item * -ftp://ftp.sunet.se/pub/lang/perl/CPAN/ +Africa -=item * -ftp://ftp.ci.uminho.pt/pub/lang/perl/ + South Africa ftp://ftp.is.co.za/programming/perl/CPAN/ =item * -ftp://ftp.cs.ruu.nl/pub/PERL/CPAN/ +Asia -=item * -ftp://ftp.demon.co.uk/pub/mirrors/perl/CPAN/ + Hong Kong ftp://ftp.hkstar.com/pub/CPAN/ + Japan ftp://ftp.jaist.ac.jp/pub/lang/perl/CPAN/ + ftp://ftp.lab.kdd.co.jp/lang/perl/CPAN/ + South Korea ftp://ftp.nuri.net/pub/CPAN/ + Taiwan ftp://dongpo.math.ncu.edu.tw/perl/CPAN/ + ftp://ftp.wownet.net/pub2/PERL/ =item * -ftp://ftp.rz.ruhr-uni-bochum.de/pub/programming/languages/perl/CPAN/ +Australasia -=item * -ftp://ftp.leo.org/pub/comp/programming/languages/perl/CPAN/ + Australia ftp://ftp.netinfo.com.au/pub/perl/CPAN/ + New Zealand ftp://ftp.tekotago.ac.nz/pub/perl/CPAN/ =item * -ftp://ftp.pasteur.fr/pub/computing/unix/perl/CPAN/ +Europe + + Austria ftp://ftp.tuwien.ac.at/pub/languages/perl/CPAN/ + Belgium ftp://ftp.kulnet.kuleuven.ac.be/pub/mirror/CPAN/ + Czech Republic ftp://sunsite.mff.cuni.cz/Languages/Perl/CPAN/ + Denmark ftp://sunsite.auc.dk/pub/languages/perl/CPAN/ + Finland ftp://ftp.funet.fi/pub/languages/perl/CPAN/ + France ftp://ftp.ibp.fr/pub/perl/CPAN/ + ftp://ftp.pasteur.fr/pub/computing/unix/perl/CPAN/ + Germany ftp://ftp.gmd.de/packages/CPAN/ + ftp://ftp.leo.org/pub/comp/programming/languages/perl/CPAN/ + ftp://ftp.mpi-sb.mpg.de/pub/perl/CPAN/ + ftp://ftp.rz.ruhr-uni-bochum.de/pub/CPAN/ + ftp://ftp.uni-erlangen.de/pub/source/Perl/CPAN/ + ftp://ftp.uni-hamburg.de/pub/soft/lang/perl/CPAN/ + Greece ftp://ftp.ntua.gr/pub/lang/perl/ + Hungary ftp://ftp.kfki.hu/pub/packages/perl/CPAN/ + Italy ftp://cis.utovrm.it/CPAN/ + the Netherlands ftp://ftp.cs.ruu.nl/pub/PERL/CPAN/ + ftp://ftp.EU.net/packages/cpan/ + Norway ftp://ftp.uit.no/pub/languages/perl/cpan/ + Poland ftp://ftp.pk.edu.pl/pub/lang/perl/CPAN/ + ftp://sunsite.icm.edu.pl/pub/CPAN/ + Portugal ftp://ftp.ci.uminho.pt/pub/lang/perl/ + ftp://ftp.telepac.pt/pub/CPAN/ + Russia ftp://ftp.sai.msu.su/pub/lang/perl/CPAN/ + Slovenia ftp://ftp.arnes.si/software/perl/CPAN/ + Spain ftp://ftp.etse.urv.es/pub/mirror/perl/ + ftp://ftp.rediris.es/mirror/CPAN/ + Sweden ftp://ftp.sunet.se/pub/lang/perl/CPAN/ + UK ftp://ftp.demon.co.uk/pub/mirrors/perl/CPAN/ + ftp://sunsite.doc.ic.ac.uk/packages/CPAN/ + ftp://unix.hensa.ac.uk/mirrors/perl-CPAN/ =item * -ftp://ftp.ibp.fr/pub/perl/CPAN/ +North America + + Ontario ftp://ftp.utilis.com/public/CPAN/ + ftp://enterprise.ic.gc.ca/pub/perl/CPAN/ + Manitoba ftp://theory.uwinnipeg.ca/pub/CPAN/ + California ftp://ftp.digital.com/pub/plan/perl/CPAN/ + ftp://ftp.cdrom.com/pub/perl/CPAN/ + Colorado ftp://ftp.cs.colorado.edu/pub/perl/CPAN/ + Florida ftp://ftp.cis.ufl.edu/pub/perl/CPAN/ + Illinois ftp://uiarchive.uiuc.edu/pub/lang/perl/CPAN/ + Massachusetts ftp://ftp.iguide.com/pub/mirrors/packages/perl/CPAN/ + New York ftp://ftp.rge.com/pub/languages/perl/ + North Carolina ftp://ftp.duke.edu/pub/perl/ + Oklahoma ftp://ftp.ou.edu/mirrors/CPAN/ + Oregon http://www.perl.org/CPAN/ + ftp://ftp.orst.edu/pub/packages/CPAN/ + Pennsylvania ftp://ftp.epix.net/pub/languages/perl/ + Texas ftp://ftp.sedl.org/pub/mirrors/CPAN/ + ftp://ftp.metronet.com/pub/perl/ =item * -ftp://ftp.funet.fi/pub/languages/perl/CPAN/ +South America -=item * -ftp://ftp.tekotago.ac.nz/pub/perl/CPAN/ - -=item * -ftp://ftp.mame.mu.oz.au/pub/perl/CPAN/ - -=item * -ftp://coombs.anu.edu.au/pub/perl/ - -=item * -ftp://dongpo.math.ncu.edu.tw/perl/CPAN/ - -=item * -ftp://ftp.lab.kdd.co.jp/lang/perl/CPAN/ - -=item * -ftp://ftp.is.co.za/programming/perl/CPAN/ + Chile ftp://sunsite.dcc.uchile.cl/pub/Lang/perl/CPAN/ =back -For an up-to-date listing of CPAN sites, +For an up-to-date listing of CPAN sites, see F or F. -=head1 Modules: Creation, Use and Abuse +=head1 Modules: Creation, Use, and Abuse (The following section is borrowed directly from Tim Bunce's modules file, available at your nearest CPAN site.) -Perl 5 implements a class using a package, but the presence of a +Perl implements a class using a package, but the presence of a package doesn't imply the presence of a class. A package is just a namespace. A class is a package that provides subroutines that can be used as methods. A method is just a subroutine that expects, as its @@ -734,9 +1083,9 @@ scheme as the original author. Use blessed references. Use the two argument form of bless to bless into the class name given as the first parameter of the constructor, -e.g.: +e.g.,: - sub new { + sub new { my $class = shift; return bless {}, $class; } @@ -744,7 +1093,7 @@ e.g.: or even this if you'd like it to be used as either a static or a virtual method. - sub new { + sub new { my $self = shift; my $class = ref($self) || $self; return bless {}, $class; @@ -769,7 +1118,7 @@ the module after __END__ either using AutoSplit or by saying: eval join('',) || die $@ unless caller(); -Does your module pass the 'empty sub-class' test? If you say +Does your module pass the 'empty subclass' test? If you say "C<@SUBCLASS::ISA = qw(YOURCLASS);>" your applications should be able to use SUBCLASS in exactly the same way as YOURCLASS. For example, does your application still work if you change: C<$obj = new YOURCLASS;> @@ -811,7 +1160,7 @@ or nature of a variable. For example: $no_caps_here function scope my() or local() variables Function and method names seem to work best as all lowercase. -E.g., C<$obj-Eas_string()>. +e.g.,, C<$obj-Eas_string()>. You can use a leading underscore to indicate that a variable or function should not be used outside the package that defined it. @@ -829,11 +1178,11 @@ short or common names to reduce the risk of name clashes. Generally anything not exported is still accessible from outside the module using the ModuleName::item_name (or C<$blessed_ref-Emethod>) syntax. By convention you can use a leading underscore on names to -informally indicate that they are 'internal' and not for public use. +indicate informally that they are 'internal' and not for public use. (It is actually possible to get private functions by saying: C. But there's no way to call that -directly as a method, since a method must have a name in the symbol +directly as a method, because a method must have a name in the symbol table.) As a general rule, if the module is trying to be object oriented @@ -842,12 +1191,12 @@ then export nothing. If it's just a collection of functions then =item Select a name for the module. -This name should be as descriptive, accurate and complete as +This name should be as descriptive, accurate, and complete as possible. Avoid any risk of ambiguity. Always try to use two or more whole words. Generally the name should reflect what is special about what the module does rather than how it does it. Please use -nested module names to informally group or categorise a module. -A module should have a very good reason not to have a nested name. +nested module names to group informally or categorize a module. +There should be a very good reason for a module not to have a nested name. Module names should begin with a capital letter. Having 57 modules all called Sort will not make life easy for anyone @@ -932,11 +1281,11 @@ The general mechanism is to assert your Copyright and then make a declaration of how others may copy/use/modify your work. Perl, for example, is supplied with two types of license: The GNU -GPL and The Artistic License (see the files README, Copying and +GPL and The Artistic License (see the files README, Copying, and Artistic). Larry has good reasons for NOT just using the GNU GPL. -My personal recommendation, out of respect for Larry, Perl and the -perl community at large is to simply state something like: +My personal recommendation, out of respect for Larry, Perl, and the +perl community at large is to state something simply like: Copyright (c) 1995 Your Name. All rights reserved. This program is free software; you can redistribute it and/or @@ -950,8 +1299,8 @@ Remember to include the other words in addition to the Copyright. To be fully compatible with the Exporter and MakeMaker modules you should store your module's version number in a non-my package -variable called $VERSION. This should be a valid floating point -number with at least two digits after the decimal (ie hundredths, +variable called $VERSION. This should be a floating point +number with at least two digits after the decimal (i.e., hundredths, e.g, C<$VERSION = "0.01">). Don't use a "1.3.2" style version. See Exporter.pm in Perl5.001m or later for details. @@ -968,7 +1317,7 @@ Usenet newsgroup. This will at least ensure very wide once-off distribution. If possible you should place the module into a major ftp archive and -include details of it's location in your announcement. +include details of its location in your announcement. Some notes about ftp archives: Please use a long descriptive file name which includes the version number. Most incoming directories @@ -985,12 +1334,12 @@ Follow the instructions and links on http://franz.ww.tu-berlin.de/modulelist -or upload to one of these sites: +or upload to one of these sites: ftp://franz.ww.tu-berlin.de/incoming - ftp://ftp.cis.ufl.edu/incoming + ftp://ftp.cis.ufl.edu/incoming -and notify upload@franz.ww.tu-berlin.de. +and notify >. By using the WWW interface you can ask the Upload Server to mirror your modules from your ftp or WWW site into your own directory on @@ -1079,8 +1428,7 @@ fragment of code built on top of the reusable modules. In these cases the application could invoked as: perl -e 'use Module::Name; method(@ARGV)' ... -or +or perl -mModule::Name ... (in perl5.002) =back -