=head1 NAME
-perlfaq - frequently asked questions about Perl ($Date: 1997/04/24 22:46:06 $)
+perlfaq - frequently asked questions about Perl ($Date: 2003/01/31 17:37:17 $)
=head1 DESCRIPTION
-This document is structured into the following sections:
+The perlfaq is divided into several documents based on topics. A table
+of contents is at the end of this document.
-=over
+=head2 Where to get the perlfaq
-=item perlfaq: Structural overview of the FAQ.
+Extracts of the perlfaq are posted regularly to
+comp.lang.perl.misc. It is available on many web sites:
+http://www.perldoc.com/ and http://faq.perl.org/
-This document.
+=head2 How to contribute to the perlfaq
-=item L<perlfaq1>: General Questions About Perl
+You may mail corrections, additions, and suggestions to
+perlfaq-workers@perl.org . This alias should not be used to
+I<ask> FAQs. It's for fixing the current FAQ. Send
+questions to the comp.lang.perl.misc newsgroup. You can
+view the source tree at http://cvs.perl.org/cvsweb/perlfaq/
+(which is outside of the main Perl source tree). The CVS
+repository notes all changes to the FAQ.
+
+=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-workers@perl.org
+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
+
+The original perlfaq was written by Tom Christiansen, then expanded
+by collaboration between Tom and Nathan Torkington. The current
+document is maintained by the perlfaq-workers (perlfaq-workers@perl.org).
+Several people have contributed answers, corrections, and comments.
+
+=head1 Author and Copyright Information
+
+Copyright (c) 1997-2003 Tom Christiansen, Nathan Torkington, and
+other contributors noted in the answers.
+
+All rights reserved.
+
+=head2 Bundled Distributions
+
+This documentation is free; you can redistribute it and/or modify it
+under the same terms as Perl itself.
+
+Irrespective of its distribution, all code examples in these files
+are hereby placed into the public domain. You are permitted and
+encouraged to use this code in your own programs for fun
+or for profit as you see fit. A simple comment in the code giving
+credit would be courteous but is not required.
+
+=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 Table of Contents
+
+=over 4
+
+=item perlfaq - this document
+
+=item perlfaq1 - General Questions About Perl
+
+=item perlfaq2 - Obtaining and Learning about Perl
+
+=item perlfaq3 - Programming Tools
+
+=item perlfaq4 - Data Manipulation
+
+=item perlfaq5 - Files and Formats
+
+=item perlfaq6 - Regular Expressions
+
+=item perlfaq7 - General Perl Language Issues
+
+=item perlfaq8 - System Interaction
+
+=item perlfaq9 - Networking
+
+
+=back
+
+
+=head1 The Questions
+
+=head2 L<perlfaq1>: General Questions About Perl
+
+Very general, high-level questions about Perl.
+
+=over 4
+
+=item *
+
+What is Perl?
+
+=item *
+
+Who supports Perl? Who develops it? Why is it free?
+
+=item *
+
+Which version of Perl should I use?
+
+=item *
+
+What are perl4 and perl5?
+
+=item *
+
+What is perl6?
+
+=item *
+
+How stable is Perl?
+
+=item *
+
+Is Perl difficult to learn?
+
+=item *
+
+How does Perl compare with other languages like Java, Python, REXX, Scheme, or Tcl?
+
+=item *
+
+Can I do [task] in Perl?
+
+=item *
+
+When shouldn't I program in Perl?
+
+=item *
+
+What's the difference between "perl" and "Perl"?
+
+=item *
+
+Is it a Perl program or a Perl script?
+
+=item *
+
+What is a JAPH?
+
+=item *
+
+Where can I get a list of Larry Wall witticisms?
+
+=item *
+
+How can I convince my sysadmin/supervisor/employees to use version 5/5.6.1/Perl instead of some other language?
+
+=back
+
+
+=head2 L<perlfaq2>: Obtaining and Learning about Perl
+
+Where to find source and documentation for Perl, support,
+and related matters.
+
+=over 4
+
+=item *
+
+What machines support Perl? Where do I get it?
+
+=item *
+
+How can I get a binary version of Perl?
+
+=item *
+
+I don't have a C compiler on my system. How can I compile perl?
+
+=item *
+
+I copied the Perl binary from one machine to another, but scripts don't work.
+
+=item *
+
+I grabbed the sources and tried to compile but gdbm/dynamic loading/malloc/linking/... failed. How do I make it work?
+
+=item *
+
+What modules and extensions are available for Perl? What is CPAN? What does CPAN/src/... mean?
+
+=item *
+
+Is there an ISO or ANSI certified version of Perl?
+
+=item *
+
+Where can I get information on Perl?
+
+=item *
+
+What are the Perl newsgroups on Usenet? Where do I post questions?
+
+=item *
+
+Where should I post source code?
+
+=item *
+
+Perl Books
+
+=item *
+
+Perl in Magazines
+
+=item *
+
+Perl on the Net: FTP and WWW Access
+
+=item *
+
+What mailing lists are there for Perl?
+
+=item *
+
+Archives of comp.lang.perl.misc
+
+=item *
+
+Where can I buy a commercial version of Perl?
+
+=item *
+
+Where do I send bug reports?
+
+=item *
+
+What is perl.com? Perl Mongers? pm.org? perl.org? cpan.org?
+
+=back
+
+
+=head2 L<perlfaq3>: Programming Tools
+
+Programmer tools and programming support.
+
+=over 4
+
+=item *
+
+How do I do (anything)?
+
+=item *
+
+How can I use Perl interactively?
+
+=item *
+
+Is there a Perl shell?
+
+=item *
+
+How do I find which modules are installed on my system?
+
+=item *
+
+How do I debug my Perl programs?
+
+=item *
+
+How do I profile my Perl programs?
+
+=item *
+
+How do I cross-reference my Perl programs?
+
+=item *
+
+Is there a pretty-printer (formatter) for Perl?
+
+=item *
+
+Is there a ctags for Perl?
+
+=item *
+
+Is there an IDE or Windows Perl Editor?
+
+=item *
+
+Where can I get Perl macros for vi?
+
+=item *
+
+Where can I get perl-mode for emacs?
+
+=item *
+
+How can I use curses with Perl?
+
+=item *
+
+How can I use X or Tk with Perl?
+
+=item *
+
+How can I generate simple menus without using CGI or Tk?
+
+=item *
+
+How can I make my Perl program run faster?
+
+=item *
+
+How can I make my Perl program take less memory?
+
+=item *
+
+Is it safe to return a reference to local or lexical data?
+
+=item *
+
+How can I free an array or hash so my program shrinks?
+
+=item *
+
+How can I make my CGI script more efficient?
+
+=item *
+
+How can I hide the source for my Perl program?
+
+=item *
+
+How can I compile my Perl program into byte code or C?
+
+=item *
+
+How can I compile Perl into Java?
+
+=item *
+
+How can I get C<#!perl> to work on [MS-DOS,NT,...]?
+
+=item *
+
+Can I write useful Perl programs on the command line?
+
+=item *
+
+Why don't Perl one-liners work on my DOS/Mac/VMS system?
+
+=item *
+
+Where can I learn about CGI or Web programming in Perl?
+
+=item *
+
+Where can I learn about object-oriented Perl programming?
+
+=item *
+
+Where can I learn about linking C with Perl? [h2xs, xsubpp]
+
+=item *
+
+I've read perlembed, perlguts, etc., but I can't embed perl in
+my C program; what am I doing wrong?
+
+=item *
+
+When I tried to run my script, I got this message. What does it mean?
+
+=item *
+
+What's MakeMaker?
+
+=back
+
+
+=head2 L<perlfaq4>: Data Manipulation
+
+Manipulating numbers, dates, strings, arrays, hashes, and
+miscellaneous data issues.
+
+=over 4
+
+=item *
+
+Why am I getting long decimals (eg, 19.9499999999999) instead of the numbers I should be getting (eg, 19.95)?
+
+=item *
+
+Why isn't my octal data interpreted correctly?
+
+=item *
+
+Does Perl have a round() function? What about ceil() and floor()? Trig functions?
+
+=item *
+
+How do I convert between numeric representations?
+
+=item *
+
+Why doesn't & work the way I want it to?
+
+=item *
+
+How do I multiply matrices?
+
+=item *
+
+How do I perform an operation on a series of integers?
+
+=item *
+
+How can I output Roman numerals?
+
+=item *
+
+Why aren't my random numbers random?
+
+=item *
+
+How do I get a random number between X and Y?
+
+=item *
+
+How do I find the day or week of the year?
+
+=item *
+
+How do I find the current century or millennium?
+
+=item *
+
+How can I compare two dates and find the difference?
+
+=item *
+
+How can I take a string and turn it into epoch seconds?
+
+=item *
+
+How can I find the Julian Day?
+
+=item *
+
+How do I find yesterday's date?
+
+=item *
+
+Does Perl have a Year 2000 problem? Is Perl Y2K compliant?
+
+=item *
+
+How do I validate input?
+
+=item *
+
+How do I unescape a string?
+
+=item *
+
+How do I remove consecutive pairs of characters?
+
+=item *
+
+How do I expand function calls in a string?
+
+=item *
+
+How do I find matching/nesting anything?
+
+=item *
+
+How do I reverse a string?
+
+=item *
+
+How do I expand tabs in a string?
+
+=item *
+
+How do I reformat a paragraph?
+
+=item *
+
+How can I access or change N characters of a string?
+
+=item *
+
+How do I change the Nth occurrence of something?
+
+=item *
+
+How can I count the number of occurrences of a substring within a string?
+
+=item *
+
+How do I capitalize all the words on one line?
+
+=item *
+
+How can I split a [character] delimited string except when inside [character]?
+
+=item *
+
+How do I strip blank space from the beginning/end of a string?
+
+=item *
+
+How do I pad a string with blanks or pad a number with zeroes?
+
+=item *
+
+How do I extract selected columns from a string?
+
+=item *
+
+How do I find the soundex value of a string?
+
+=item *
+
+How can I expand variables in text strings?
+
+=item *
+
+What's wrong with always quoting "$vars"?
+
+=item *
+
+Why don't my E<lt>E<lt>HERE documents work?
+
+=item *
+
+What is the difference between a list and an array?
+
+=item *
+
+What is the difference between $array[1] and @array[1]?
+
+=item *
+
+How can I remove duplicate elements from a list or array?
+
+=item *
+
+How can I tell whether a certain element is contained in a list or array?
+
+=item *
+
+How do I compute the difference of two arrays? How do I compute the intersection of two arrays?
+
+=item *
+
+How do I test whether two arrays or hashes are equal?
+
+=item *
+
+How do I find the first array element for which a condition is true?
+
+=item *
+
+How do I handle linked lists?
+
+=item *
+
+How do I handle circular lists?
+
+=item *
+
+How do I shuffle an array randomly?
+
+=item *
+
+How do I process/modify each element of an array?
+
+=item *
+
+How do I select a random element from an array?
+
+=item *
+
+How do I permute N elements of a list?
+
+=item *
+
+How do I sort an array by (anything)?
+
+=item *
+
+How do I manipulate arrays of bits?
+
+=item *
+
+Why does defined() return true on empty arrays and hashes?
+
+=item *
+
+How do I process an entire hash?
+
+=item *
+
+What happens if I add or remove keys from a hash while iterating over it?
+
+=item *
+
+How do I look up a hash element by value?
+
+=item *
+
+How can I know how many entries are in a hash?
+
+=item *
+
+How do I sort a hash (optionally by value instead of key)?
+
+=item *
+
+How can I always keep my hash sorted?
+
+=item *
+
+What's the difference between "delete" and "undef" with hashes?
+
+=item *
+
+Why don't my tied hashes make the defined/exists distinction?
+
+=item *
+
+How do I reset an each() operation part-way through?
+
+=item *
+
+How can I get the unique keys from two hashes?
+
+=item *
+
+How can I store a multidimensional array in a DBM file?
+
+=item *
+
+How can I make my hash remember the order I put elements into it?
+
+=item *
+
+Why does passing a subroutine an undefined element in a hash create it?
+
+=item *
+
+How can I make the Perl equivalent of a C structure/C++ class/hash or array of hashes or arrays?
+
+=item *
+
+How can I use a reference as a hash key?
+
+=item *
+
+How do I handle binary data correctly?
+
+=item *
+
+How do I determine whether a scalar is a number/whole/integer/float?
+
+=item *
+
+How do I keep persistent data across program calls?
+
+=item *
+
+How do I print out or copy a recursive data structure?
+
+=item *
+
+How do I define methods for every class/object?
+
+=item *
+
+How do I verify a credit card checksum?
+
+=item *
+
+How do I pack arrays of doubles or floats for XS code?
+
+=back
+
+
+=head2 L<perlfaq5>: Files and Formats
+
+I/O and the "f" issues: filehandles, flushing, formats, and footers.
+
+=over 4
+
+=item *
+
+How do I flush/unbuffer an output filehandle? Why must I do this?
+
+=item *
+
+How do I change one line in a file/delete a line in a file/insert a line in the middle of a file/append to the beginning of a file?
+
+=item *
+
+How do I count the number of lines in a file?
+
+=item *
+
+How can I use Perl's C<-i> option from within a program?
+
+=item *
+
+How do I make a temporary file name?
+
+=item *
+
+How can I manipulate fixed-record-length files?
+
+=item *
+
+How can I make a filehandle local to a subroutine? How do I pass filehandles between subroutines? How do I make an array of filehandles?
+
+=item *
+
+How can I use a filehandle indirectly?
+
+=item *
+
+How can I set up a footer format to be used with write()?
+
+=item *
+
+How can I write() into a string?
+
+=item *
+
+How can I output my numbers with commas added?
+
+=item *
+
+How can I translate tildes (~) in a filename?
+
+=item *
+
+How come when I open a file read-write it wipes it out?
+
+=item *
+
+Why do I sometimes get an "Argument list too long" when I use E<lt>*E<gt>?
+
+=item *
+
+Is there a leak/bug in glob()?
+
+=item *
+
+How can I open a file with a leading ">" or trailing blanks?
+
+=item *
+
+How can I reliably rename a file?
+
+=item *
+
+How can I lock a file?
+
+=item *
+
+Why can't I just open(FH, "E<gt>file.lock")?
+
+=item *
+
+I still don't get locking. I just want to increment the number in the file. How can I do this?
+
+=item *
+
+All I want to do is append a small amount of text to the end of a file. Do I still have to use locking?
+
+=item *
+
+How do I randomly update a binary file?
+
+=item *
+
+How do I get a file's timestamp in perl?
+
+=item *
+
+How do I set a file's timestamp in perl?
+
+=item *
+
+How do I print to more than one file at once?
+
+=item *
+
+How can I read in an entire file all at once?
+
+=item *
+
+How can I read in a file by paragraphs?
+
+=item *
+
+How can I read a single character from a file? From the keyboard?
+
+=item *
+
+How can I tell whether there's a character waiting on a filehandle?
+
+=item *
+
+How do I do a C<tail -f> in perl?
+
+=item *
+
+How do I dup() a filehandle in Perl?
+
+=item *
-Very general, high-level information about Perl.
+How do I close a file descriptor by number?
-=item L<perlfaq2>: Obtaining and Learning about Perl
+=item *
-Where to find source and documentation to Perl, support and training,
-and related matters.
+Why can't I use "C:\temp\foo" in DOS paths? What doesn't `C:\temp\foo.exe` work?
-=item L<perlfaq3>: Programming Tools
+=item *
-Programmer tools and programming support.
+Why doesn't glob("*.*") get all the files?
-=item L<perlfaq4>: Data Manipulation
+=item *
-Manipulating numbers, dates, strings, arrays, hashes, and
-miscellaneous data issues.
+Why does Perl let me delete read-only files? Why does C<-i> clobber protected files? Isn't this a bug in Perl?
+
+=item *
+
+How do I select a random line from a file?
+
+=item *
+
+Why do I get weird spaces when I print an array of lines?
-=item L<perlfaq5>: Files and Formats
+=back
-I/O and the "f" issues: filehandles, flushing, formats and footers.
-=item L<perlfaq6>: Regexps
+=head2 L<perlfaq6>: Regular Expressions
Pattern matching and regular expressions.
-=item L<perlfaq7>: General Perl Language Issues
+=over 4
+
+=item *
+
+How can I hope to use regular expressions without creating illegible and unmaintainable code?
+
+=item *
+
+I'm having trouble matching over more than one line. What's wrong?
+
+=item *
+
+How can I pull out lines between two patterns that are themselves on different lines?
+
+=item *
+
+I put a regular expression into $/ but it didn't work. What's wrong?
+
+=item *
+
+How do I substitute case insensitively on the LHS while preserving case on the RHS?
+
+=item *
+
+How can I make C<\w> match national character sets?
+
+=item *
+
+How can I match a locale-smart version of C</[a-zA-Z]/>?
+
+=item *
+
+How can I quote a variable to use in a regex?
+
+=item *
+
+What is C</o> really for?
+
+=item *
+
+How do I use a regular expression to strip C style comments from a file?
+
+=item *
+
+Can I use Perl regular expressions to match balanced text?
+
+=item *
+
+What does it mean that regexes are greedy? How can I get around it?
+
+=item *
+
+How do I process each word on each line?
+
+=item *
+
+How can I print out a word-frequency or line-frequency summary?
+
+=item *
+
+How can I do approximate matching?
+
+=item *
+
+How do I efficiently match many regular expressions at once?
+
+=item *
+
+Why don't word-boundary searches with C<\b> work for me?
+
+=item *
+
+Why does using $&, $`, or $' slow my program down?
+
+=item *
+
+What good is C<\G> in a regular expression?
+
+=item *
+
+Are Perl regexes DFAs or NFAs? Are they POSIX compliant?
+
+=item *
+
+What's wrong with using grep or map in a void context?
+
+=item *
+
+How can I match strings with multibyte characters?
+
+=item *
+
+How do I match a pattern that is supplied by the user?
+
+=back
+
+
+=head2 L<perlfaq7>: General Perl Language Issues
General Perl language issues that don't clearly fit into any of the
other sections.
-=item L<perlfaq8>: System Interaction
+=over 4
+
+=item *
+
+Can I get a BNF/yacc/RE for the Perl language?
+
+=item *
+
+What are all these $@%&* punctuation signs, and how do I know when to use them?
+
+=item *
+
+Do I always/never have to quote my strings or use semicolons and commas?
+
+=item *
+
+How do I skip some return values?
+
+=item *
+
+How do I temporarily block warnings?
+
+=item *
+
+What's an extension?
+
+=item *
+
+Why do Perl operators have different precedence than C operators?
+
+=item *
+
+How do I declare/create a structure?
+
+=item *
+
+How do I create a module?
+
+=item *
+
+How do I create a class?
+
+=item *
+
+How can I tell if a variable is tainted?
+
+=item *
+
+What's a closure?
+
+=item *
+
+What is variable suicide and how can I prevent it?
+
+=item *
+
+How can I pass/return a {Function, FileHandle, Array, Hash, Method, Regex}?
+
+=item *
+
+How do I create a static variable?
+
+=item *
+
+What's the difference between dynamic and lexical (static) scoping? Between local() and my()?
+
+=item *
+
+How can I access a dynamic variable while a similarly named lexical is in scope?
+
+=item *
+
+What's the difference between deep and shallow binding?
+
+=item *
+
+Why doesn't "my($foo) = E<lt>FILEE<gt>;" work right?
+
+=item *
+
+How do I redefine a builtin function, operator, or method?
+
+=item *
+
+What's the difference between calling a function as &foo and foo()?
+
+=item *
+
+How do I create a switch or case statement?
+
+=item *
+
+How can I catch accesses to undefined variables, functions, or methods?
+
+=item *
+
+Why can't a method included in this same file be found?
+
+=item *
+
+How can I find out my current package?
+
+=item *
+
+How can I comment out a large block of perl code?
+
+=item *
+
+How do I clear a package?
+
+=item *
+
+How can I use a variable as a variable name?
+
+=item *
+
+What does "bad interpreter" mean?
+
+=back
+
+
+=head2 L<perlfaq8>: System Interaction
Interprocess communication (IPC), control over the user-interface
(keyboard, screen and pointing devices).
-=item L<perlfaq9>: Networking
+=over 4
-Networking, the Internet, and a few on the web.
+=item *
-=back
+How do I find out which operating system I'm running under?
-=head2 Where to get this document
+=item *
-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/ .
+How come exec() doesn't return?
-=head2 How to contribute to this document
+=item *
-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.
+How do I do fancy stuff with the keyboard/screen/mouse?
-=head2 What will happen if you mail your Perl programming problems to the authors
+=item *
-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.
+How do I print something out in color?
-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.
+=item *
-=head1 Credits
+How do I read just one key without waiting for a return key?
-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.
+=item *
-=head1 Author and Copyright Information
+How do I check whether input is ready on the keyboard?
-Copyright (c) 1997 Tom Christiansen and Nathan Torkington.
-All rights reserved.
+=item *
-=head2 Noncommercial Reproduction
+How do I clear the screen?
-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.
+=item *
-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.
+How do I get the screen size?
-=head2 Commercial Reproduction
+=item *
-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.
+How do I ask the user for a password?
-=head2 Disclaimer
+=item *
-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.
+How do I read and write the serial port?
+
+=item *
+
+How do I decode encrypted password files?
+
+=item *
+
+How do I start a process in the background?
+
+=item *
+
+How do I trap control characters/signals?
+
+=item *
+
+How do I modify the shadow password file on a Unix system?
+
+=item *
+
+How do I set the time and date?
+
+=item *
+
+How can I sleep() or alarm() for under a second?
+
+=item *
+
+How can I measure time under a second?
+
+=item *
+
+How can I do an atexit() or setjmp()/longjmp()? (Exception handling)
+
+=item *
+
+Why doesn't my sockets program work under System V (Solaris)? What does the error message "Protocol not supported" mean?
+
+=item *
+
+How can I call my system's unique C functions from Perl?
+
+=item *
+
+Where do I get the include files to do ioctl() or syscall()?
+
+=item *
+
+Why do setuid perl scripts complain about kernel problems?
+
+=item *
+
+How can I open a pipe both to and from a command?
+
+=item *
+
+Why can't I get the output of a command with system()?
+
+=item *
+
+How can I capture STDERR from an external command?
+
+=item *
+
+Why doesn't open() return an error when a pipe open fails?
+
+=item *
+
+What's wrong with using backticks in a void context?
+
+=item *
+
+How can I call backticks without shell processing?
+
+=item *
+
+Why can't my script read from STDIN after I gave it EOF (^D on Unix, ^Z on MS-DOS)?
+
+=item *
+
+How can I convert my shell script to perl?
+
+=item *
+
+Can I use perl to run a telnet or ftp session?
+
+=item *
+
+How can I write expect in Perl?
+
+=item *
+
+Is there a way to hide perl's command line from programs such as "ps"?
+
+=item *
+
+I {changed directory, modified my environment} in a perl script. How come the change disappeared when I exited the script? How do I get my changes to be visible?
+
+=item *
+
+How do I close a process's filehandle without waiting for it to complete?
+
+=item *
+
+How do I fork a daemon process?
+
+=item *
+
+How do I find out if I'm running interactively or not?
+
+=item *
+
+How do I timeout a slow event?
+
+=item *
-=head1 Changes
+How do I set CPU limits?
+
+=item *
+
+How do I avoid zombies on a Unix system?
+
+=item *
+
+How do I use an SQL database?
+
+=item *
+
+How do I make a system() exit on control-C?
+
+=item *
+
+How do I open a file without blocking?
+
+=item *
+
+How do I install a module from CPAN?
+
+=item *
+
+What's the difference between require and use?
+
+=item *
+
+How do I keep my own module/library directory?
+
+=item *
+
+How do I add the directory my program lives in to the module/library search path?
+
+=item *
+
+How do I add a directory to my include path at runtime?
+
+=item *
+
+What is socket.ph and where do I get it?
+
+=back
+
+
+=head2 L<perlfaq9>: Networking
+
+Networking, the internet, and a few on the web.
=over 4
-=item 24/April/97
+=item *
+
+What is the correct form of response from a CGI script?
+
+=item *
+
+My CGI script runs from the command line but not the browser. (500 Server Error)
+
+=item *
+
+How can I get better error messages from a CGI program?
+
+=item *
+
+How do I remove HTML from a string?
-Style and whitespace changes from Chip, new question on reading one
-character at a time from a terminal using POSIX from Tom.
+=item *
-=item 23/April/97
+How do I extract URLs?
-Added http://www.oasis.leo.org/perl/ to L<perlfaq2>. Style fix to
-L<perlfaq3>. 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<perlfaq4>. Added example of passing and storing
-filehandles, added commify to L<perlfaq5>. Restored variable suicide,
-and added mass commenting to L<perlfaq7>. Added Net::Telnet, fixed
-backticks, added reader/writer pair to telnet question, added FindBin,
-grouped module questions together in L<perlfaq8>. Expanded caveats
-for the simple URL extractor, gave LWP example, added CGI security
-question, expanded on the email address answer in L<perlfaq9>.
+=item *
-=item 25/March/97
+How do I download a file from the user's machine? How do I open a file on another machine?
-Added more info to the binary distribution section of L<perlfaq2>.
-Added Net::Telnet to L<perlfaq6>. Fixed typos in L<perlfaq8>. Added
-mail sending example to L<perlfaq9>. Added Merlyn's columns to
-L<perlfaq2>.
+=item *
-=item 18/March/97
+How do I make a pop-up menu in HTML?
-Added the DATE to the NAME section, indicating which sections have
-changed.
+=item *
-Mentioned SIGPIPE and L<perlipc> in the forking open answer in
-L<perlfaq8>.
+How do I fetch an HTML file?
-Fixed description of a regular expression in L<perlfaq4>.
+=item *
-=item 17/March/97 Version
+How do I automate an HTML form submission?
-Various typos fixed throughout.
+=item *
-Added new question on Perl BNF on L<perlfaq7>.
+How do I decode or create those %-encodings on the web?
-=item Initial Release: 11/March/97
+=item *
-This is the initial release of version 3 of the FAQ; consequently there
-have been no changes since its initial release.
+How do I redirect to another page?
+
+=item *
+
+How do I put a password on my web pages?
+
+=item *
+
+How do I edit my .htpasswd and .htgroup files with Perl?
+
+=item *
+
+How do I make sure users can't enter values into a form that cause my CGI script to do bad things?
+
+=item *
+
+How do I parse a mail header?
+
+=item *
+
+How do I decode a CGI form?
+
+=item *
+
+How do I check a valid mail address?
+
+=item *
+
+How do I decode a MIME/BASE64 string?
+
+=item *
+
+How do I return the user's mail address?
+
+=item *
+
+How do I send mail?
+
+=item *
+
+How do I use MIME to make an attachment to a mail message?
+
+=item *
+
+How do I read mail?
+
+=item *
+
+How do I find out my hostname/domainname/IP address?
+
+=item *
+
+How do I fetch a news article or the active newsgroups?
+
+=item *
+
+How do I fetch/put an FTP file?
+
+=item *
+
+How can I do RPC in Perl?
=back
+
+
projects / p5sagit/p5-mst-13.2.git / blobdiff