=head1 NAME perlfaq - frequently asked questions about Perl ($Date: 1997/04/24 22:46:06 $) =head1 DESCRIPTION This document is structured into the following sections: =over =item perlfaq: Structural overview of the FAQ. This document. =item L: General Questions About Perl Very general, high-level information about Perl. =item L: Obtaining and Learning about Perl Where to find source and documentation to Perl, support and training, and related matters. =item L: Programming Tools Programmer tools and programming support. =item L: Data Manipulation Manipulating numbers, dates, strings, arrays, hashes, and miscellaneous data issues. =item L: Files and Formats I/O and the "f" issues: filehandles, flushing, formats and footers. =item L: Regexps Pattern matching and regular expressions. =item L: General Perl Language Issues General Perl language issues that don't clearly fit into any of the other sections. =item L: System Interaction Interprocess communication (IPC), control over the user-interface (keyboard, screen and pointing devices). =item L: Networking Networking, the Internet, and a few on the web. =back =head2 Where to get this document This document is posted regularly to comp.lang.perl.announce and several other related newsgroups. It is available in a variety of formats from CPAN in the /CPAN/doc/FAQs/FAQ/ directory, or on the web at http://www.perl.com/perl/faq/ . =head2 How to contribute to this document You may mail corrections, additions, and suggestions to perlfaq-suggestions@perl.com . Mail sent to the old perlfaq alias will merely cause the FAQ to be sent to you. =head2 What will happen if you mail your Perl programming problems to the authors Your questions will probably go unread, unless they're suggestions of new questions to add to the FAQ, in which case they should have gone to the perlfaq-suggestions@perl.com instead. You should have read section 2 of this faq. There you would have learned that comp.lang.perl.misc is the appropriate place to go for free advice. If your question is really important and you require a prompt and correct answer, you should hire a consultant. =head1 Credits When I first began the Perl FAQ in the late 80s, I never realized it would have grown to over a hundred pages, nor that Perl would ever become so popular and widespread. This document could not have been written without the tremendous help provided by Larry Wall and the rest of the Perl Porters. =head1 Author and Copyright Information Copyright (c) 1997 Tom Christiansen and Nathan Torkington. All rights reserved. =head2 Noncommercial Reproduction Permission is granted to distribute this document, in part or in full, via electronic means or printed copy providing that (1) that all credits and copyright notices be retained, (2) that no charges beyond reproduction be involved, and (3) that a reasonable attempt be made to use the most current version available. Furthermore, you may include this document in any distribution of the full Perl source or binaries, in its verbatim documentation, or on a complete dump of the CPAN archive, providing that the three stipulations given above continue to be met. =head2 Commercial Reproduction Requests for all other distribution rights, including the incorporation in part or in full of this text or its code into commercial products such as but not limited to books, magazine articles, or CD-ROMs, must be made to perlfaq-legal@perl.com. Any commercial use of any portion of this document without prior written authorization by its authors will be subject to appropriate action. =head2 Disclaimer This information is offered in good faith and in the hope that it may be of use, but is not guaranteed to be correct, up to date, or suitable for any particular purpose whatsoever. The authors accept no liability in respect of this information or its use. =head1 Changes =over 4 =item 24/April/97 Style and whitespace changes from Chip, new question on reading one character at a time from a terminal using POSIX from Tom. =item 23/April/97 Added http://www.oasis.leo.org/perl/ to L. Style fix to L. Added floating point precision, fixed complex number arithmetic, cross-references, caveat for Text::Wrap, alternative answer for initial capitalizing, fixed incorrect regexp, added example of Tie::IxHash to L. Added example of passing and storing filehandles, added commify to L. Restored variable suicide, and added mass commenting to L. Added Net::Telnet, fixed backticks, added reader/writer pair to telnet question, added FindBin, grouped module questions together in L. Expanded caveats for the simple URL extractor, gave LWP example, added CGI security question, expanded on the email address answer in L. =item 25/March/97 Added more info to the binary distribution section of L. Added Net::Telnet to L. Fixed typos in L. Added mail sending example to L. Added Merlyn's columns to L. =item 18/March/97 Added the DATE to the NAME section, indicating which sections have changed. Mentioned SIGPIPE and L in the forking open answer in L. Fixed description of a regular expression in L. =item 17/March/97 Version Various typos fixed throughout. Added new question on Perl BNF on L. =item Initial Release: 11/March/97 This is the initial release of version 3 of the FAQ; consequently there have been no changes since its initial release. =back