[inseparable changes from match from perl-5.003_97g to perl-5.003_97h]

 BUILD PROCESS

Subject: Fix up Linux hints for tcsh, and Configure patch
Date: Tue, 22 Apr 1997 11:02:27 -0400 (EDT)
From: Andy Dougherty <doughera@lafcol.lafayette.edu>
Files: Configure hints/linux.sh
Msg-ID: Pine.SOL.3.95q.970422101051.2506C-100000@fractal.lafayette.e

    (applied based on p5p patch as commit 1eb1b1cb9647b817d039bb17afa3e74940b5ef92)

Subject: There is no standard answer to 'Use suidperl?'
From: Chip Salzenberg <chip@perl.com>
Files: hints/bsdos.sh hints/freebsd.sh hints/linux.sh hints/machten_2.sh

 CORE LANGUAGE CHANGES

Subject: Support PRINTF for tied handles
Date: Sun, 20 Apr 1997 18:26:13 -0400
From: Doug MacEachern <dougm@opengroup.org>
Files: pod/perldelta.pod pod/perltie.pod pp_sys.c t/op/misc.t
Msg-ID: 199704202226.SAA08032@postman.osf.org

    (applied based on p5p patch as commit e7c5525577c16ee25e3521e86aca2b5105dba394)

 CORE PORTABILITY

Subject: Fix bitwise shifts and pack('w') on Crays
From: Chip Salzenberg <chip@perl.com>
Files: pp.c

 DOCUMENTATION

Subject: FAQ udpate (23-apr-97)
Date: Wed, 23 Apr 1997 12:22:55 -0600 (MDT)
From: Nathan Torkington <gnat@prometheus.frii.com>
Files: pod/perlfaq*.pod

    private-msgid: 199704231822.MAA05074@prometheus.frii.com

 OTHER CORE CHANGES

Subject: Mondo Cool patch for buffer safety and convenience
From: Chip Salzenberg <chip@perl.com>
Files: XSUB.h doop.c dump.c ext/DynaLoader/dl_dlopen.xs ext/DynaLoader/dl_hpux.xs ext/DynaLoader/dl_next.xs ext/DynaLoader/dlutils.c ext/ODBM_File/ODBM_File.xs global.sym gv.c interp.sym mg.c op.c perl.c perl.h pod/perlguts.pod pp.c pp_ctl.c pp_hot.c pp_sys.c proto.h regcomp.c regexec.c sv.c toke.c util.c

Subject: Problems with glob
Date: Sun, 20 Apr 1997 02:44:32 -0400 (EDT)
From: Ilya Zakharevich <ilya@math.ohio-state.edu>
Files: op.c
Msg-ID: 1997Apr20.024432.1941365@hmivax.humgen.upenn.edu

    (applied based on p5p patch as commit a1230b335277820e65b8a9454ab751341204cf4f)

Subject: Fix scalar leak in closures
From: Chip Salzenberg <chip@perl.com>
Files: op.c scope.c

Subject: Refine error messages re: anon subs' prototypes
From: Chip Salzenberg <chip@perl.com>
Files: op.c

Subject: Outermost scope is void, not scalar
From: Chip Salzenberg <chip@perl.com>
Files: pp_ctl.c

1 files changed, 73 insertions, 8 deletions

diff --git a/pod/perlfaq4.pod b/pod/perlfaq4.pod
index d3a7e8ccb9..7c57d58d7d 100644
--- a/pod/perlfaq4.pod
+++ b/pod/perlfaq4.pod
@@ -1,6 +1,6 @@
 =head1 NAME
 
-perlfaq4 - Data Manipulation ($Revision: 1.17 $, $Date: 1997/03/25 18:16:24 $)
+perlfaq4 - Data Manipulation ($Revision: 1.18 $, $Date: 1997/04/23 18:04:37 $)
 
 =head1 DESCRIPTION
 
@@ -10,6 +10,34 @@ data issues.
 
 =head1 Data: Numbers
 
+=head2 Why am I getting long decimals (eg, 19.9499999999999) instead of the numbers I should be getting (eg, 19.95)?
+
+Internally, your computer represents floating-point numbers in binary.
+Floating-point numbers read in from a file, or appearing as literals
+in your program, are converted from their decimal floating-point
+representation (eg, 19.95) to the internal binary representation.
+
+However, 19.95 can't be precisely represented as a binary
+floating-point number, just like 1/3 can't be exactly represented as a
+decimal floating-point number.  The computer's binary representation
+of 19.95, therefore, isn't exactly 19.95.
+
+When a floating-point number gets printed, the binary floating-point
+representation is converted back to decimal.  These decimal numbers
+are displayed in either the format you specify with printf(), or the
+current output format for numbers (see L<perlvar/"$#"> if you use
+print.  C<$#> has a different default value in Perl5 than it did in
+Perl4.  Changing C<$#> yourself is deprecated.
+
+This affects B<all> computer languages that represent decimal
+floating-point numbers in binary, not just Perl.  Perl provides
+arbitrary-precision decimal numbers with the Math::BigFloat module
+(part of the standard Perl distribution), but mathematical operations
+are consequently slower.
+
+To get rid of the superfluous digits, just use a format (eg,
+C<printf("%.2f", 19.95)>) to get the required precision.
+
 =head2 Why isn't my octal data interpreted correctly?
 
 Perl only understands octal and hex numbers as such when they occur
@@ -36,10 +64,12 @@ The POSIX module (part of the standard perl distribution) implements
 ceil(), floor(), and a number of other mathematical and trigonometric
 functions.
 
-The Math::Complex module (part of the standard perl distribution)
-defines a number of mathematical functions that can also work on real
-numbers.  It's not as efficient as the POSIX library, but the POSIX
-library can't work with complex numbers.
+In 5.000 to 5.003 Perls, trigonometry was done in the Math::Complex
+module.  With 5.004, the Math::Trig module (part of the standard perl
+distribution) implements the trigonometric functions. Internally it
+uses the Math::Complex module and some functions can break out from
+the real axis into the complex plane, for example the inverse sine of
+2.
 
 Rounding in financial applications can have serious implications, and
 the rounding method used should be specified precisely.  In these
@@ -199,6 +229,9 @@ arbitrary expressions:
 
     print "That yields ${\($n + 5)} widgets\n";
 
+See also "How can I expand variables in text strings?" in this section
+of the FAQ.
+
 =head2 How do I find matching/nesting anything?
 
 This isn't something that can be tackled in one regular expression, no
@@ -234,6 +267,9 @@ Use Text::Wrap (part of the standard perl distribution):
     use Text::Wrap;
     print wrap("\t", '  ', @paragraphs);
 
+The paragraphs you give to Text::Wrap may not contain embedded
+newlines.  Text::Wrap doesn't justify the lines (flush-right).
+
 =head2 How can I access/change the first N letters of a string?
 
 There are many ways.  If you just want to grab a copy, use
@@ -271,7 +307,7 @@ C<tr///> function like so:
 
     $string = "ThisXlineXhasXsomeXx'sXinXit":
     $count = ($string =~ tr/X//);
-    print "There are $count X characters in the string";
+    print "There are $count X charcters in the string";
 
 This is fine if you are just looking for a single character.  However,
 if you are trying to count multiple character substrings within a
@@ -289,6 +325,18 @@ To make the first letter of each word upper case:
 
         $line =~ s/\b(\w)/\U$1/g;
 
+This has the strange effect of turning "C<don't do it>" into "C<Don'T
+Do It>".  Sometimes you might want this, instead (Suggested by Brian
+Foy E<lt>comdog@computerdog.comE<gt>):
+
+    $string =~ s/ (
+                 (^\w)    #at the beginning of the line
+                   |      # or
+                 (\s\w)   #preceded by whitespace
+                   )
+                /\U$1/xg;
+    $string =~ /([\w']+)/\u\L$1/g;
+
 To make the whole line upper case:
 
         $line = uc($line);
@@ -321,6 +369,11 @@ suggests (assuming your string is contained in $text):
      }gx;
      push(@new, undef) if substr($text,-1,1) eq ',';
 
+If you want to represent quotation marks inside a
+quotation-mark-delimited field, escape them with backslashes (eg,
+C<"like \"this\"").  Unescaping them is a task addressed earlier in
+this section.
+
 Alternatively, the Text::ParseWords module (part of the standard perl
 distribution) lets you say:
 
@@ -368,6 +421,9 @@ substitution:
 Which is bizarre enough that you'll probably actually need an EEG
 afterwards. :-)
 
+See also "How do I expand function calls in a string?" in this section
+of the FAQ.
+
 =head2 What's wrong with always quoting "$vars"?
 
 The problem is that those double-quotes force stringification,
@@ -668,7 +724,7 @@ that's come to be known as the Schwartzian Transform:
 
     @sorted = map  { $_->[0] }
 	      sort { $a->[1] cmp $b->[1] }
-	      map  { [ $_, uc((/\d+\s*(\S+) )[0] ] } @data;
+	      map  { [ $_, uc((/\d+\s*(\S+)/ )[0] ] } @data;
 
 If you need to sort on several fields, the following paradigm is useful.
 
@@ -900,7 +956,7 @@ they end up doing is not what they do with ordinary hashes.
 Using C<keys %hash> in a scalar context returns the number of keys in
 the hash I<and> resets the iterator associated with the hash.  You may
 need to do this if you use C<last> to exit a loop early so that when you
-reenter it, the hash iterator has been reset.
+re-enter it, the hash iterator has been reset.
 
 =head2 How can I get the unique keys from two hashes?
 
@@ -938,6 +994,14 @@ it on top of either DB_File or GDBM_File.
 
 Use the Tie::IxHash from CPAN.
 
+    use Tie::IxHash;
+    tie(%myhash, Tie::IxHash);
+    for ($i=0; $i<20; $i++) {
+        $myhash{$i} = 2*$i;
+    }
+    @keys = keys %myhash;
+    # @keys = (0,1,2,3,...)
+
 =head2 Why does passing a subroutine an undefined element in a hash create it?
 
 If you say something like:
@@ -1035,3 +1099,4 @@ Get the Business::CreditCard module from CPAN.
 
 Copyright (c) 1997 Tom Christiansen and Nathan Torkington.
 All rights reserved.  See L<perlfaq> for distribution information.
+