Merge branch 'master' of https://github.com/manwar/perlweeklychallenge-club

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diff --git a/challenge-029/burkhard-nickels/README b/challenge-029/burkhard-nickels/README
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index 0000000000..f5e16bb98b
--- /dev/null
+++ b/challenge-029/burkhard-nickels/README
@@ -0,0 +1 @@
+Solutions by Burkhard Nickels.
diff --git a/challenge-029/burkhard-nickels/perl5/ch-1.pl b/challenge-029/burkhard-nickels/perl5/ch-1.pl
new file mode 100644
index 0000000000..f2ce667ddd
--- /dev/null
+++ b/challenge-029/burkhard-nickels/perl5/ch-1.pl
@@ -0,0 +1,663 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+my $tmp = "tmp";
+if(!-d $tmp) { 
+	mkdir $tmp;
+	print "Created folder $tmp!\n";
+	# die "Error: Folder tmp/ does not exist!"; 
+}
+
+BEGIN {
+	$ENV{LD_LIBRARY_PATH}="tmp";
+	my $ret = qx[ echo \$LD_LIBRARY_PATH; export \$LD_LIBRARY_PATH ];
+	print "ENV: $ret\n";
+}
+
+# --------------------------------------------------
+my $bn = "pwc29";
+my $title = "Perl Weekly Challenge #029";
+
+my $css = <<END_CSS;
+body { margin-left:auto; margin-right:auto; width:80%; }
+h1   { border-bottom:4px solid red; }
+h2   { border-bottom:2px solid orange; }
+pre  { border:2px solid grey; background-color:#eef; padding:10px; }
+li   { padding:5px; }
+a    { text-decoration:none; color:black; padding:4px; }
+a:hover { background-color: brown; color:white; }
+._podblock_ { width:100%; background-color:black; color:white; padding:10px; }
+END_CSS
+
+
+sub create_html {
+	print "Create Web ...\n";
+	open(my $fh,">$bn.css") or die "Cant open $bn.css!\n";
+	print $fh $css;
+	close $fh;
+	print "\t$bn.css created!\n";
+	my $ret = qx[pod2html --header --title="$title" --css=$bn.css $bn.pl > $bn.html];
+	print "\t$bn.html created!\n";
+}
+
+
+# --------------------------------------------------
+=head1 Perl Weekly Challenge #029 
+
+I want to try the Perl Weekly Challenge. During I am working on it, I get
+more and more ideas what to do next. So I decided to put all of the work in
+only one file. The result is this one and only file "pwd29.pl" for several solutions.
+
+The tasks for my first Perl Weekly Challenge are:
+
+Task #1: Write a script to demonstate brace expansion.
+
+Task #2: Write a script to demonstate calling a C function.
+
+=head1 In brief
+
+Cite from the Song "Ich weiss was ich will" from Udo Juergens: 
+"Ich hab noch nie in meinem Leben Berge versetzt, ich tu'es jetzt."
+(chuck, 12.10.2019)
+
+I will do the following trials:
+
+=over 4
+
+=item * Task #1 and #2, Documentation on PWC
+
+I created an inline documentation in POD format. With arg "html" pod2html is
+executed to convert the POD to HTML. The files "pwc29.css" and "pwc29.html"
+are created.
+
+ # perldoc pwc29.pl
+   or
+ # ./pwc29.pl html
+
+=item * Task #1, Brace expansion 1: Pattern matching and split
+
+ # ./pwc29.pl brace1 "Perl {Daily,Weekly,Monthly} Challenge"
+
+=item * Task #1, Brace expansion 2: Code compressed
+
+ # ./pwc29.pl brace1 "Perl {Daily,Weekly,Monthly} Challenge"
+
+=item * Task #1 and #2, Brace expansion 3: C Inline
+
+The C function brex() is created and used with the "Inline" module.
+
+ # ./pwc29.pl brace3 "Perl {Daily,Weekly,Monthly} Challenge"
+
+=item * Task #1 and #2, Brace expansion 4: External C program system call
+
+The main C function is created and written to file "brex.c" together with
+the former created "brex()" function. Than the C program "brex" and C library
+libbrex.so are created with gcc.
+
+ # ./pwc29.pl brace4 "Perl {Daily,Weekly,Monthly} Challenge"
+
+=item * Task #1 and #2, Brace expansion 5 and 6; C-Code with XS
+
+The Brex.pm Perl Module with XS-Loader and the Brex.xs file to create
+the interface module are created with arg "brace5". With arg "brace6"
+the new Perl XS code is executed.
+
+ # ./pwc29.pl brace5 "Perl {Daily,Weekly,Monthly} Challenge"
+	and
+ # ./pwc29.pl brace6 "Perl {Daily,Weekly,Monthly} Challenge"
+
+=back
+
+=cut
+
+# -----------------------------------------------------------------
+=head1 Task #1 - Brace expansion 1: Pattern matching and split
+
+Also the shell is doing brace expansion, so I need to put the whole
+string in double quotes.
+
+ ./pwc29.pl brace1 "Perl {Daily,Weekly,Monthly} Challenge"
+ IN: Perl {Daily,Weekly,Monthly} Challenge
+ Perl  Daily  Challenge
+ Perl  Weekly  Challenge
+ Perl  Monthly  Challenge
+
+The perl script is only doing pattern matching and split the list
+of comma separated strings.
+
+ my $str = $ARGV[0] || die "Error: String not set!\n";
+ print "IN: $str\n";
+
+ $str =~ /^(.*)\{(.*)\}(.*)/ || die "No braces in string!\n";
+ my ($a,$b,$c) = ($1,$2,$3);
+ my @ele = split(",",$b);
+
+ foreach my $e (@ele) { print "$a $e $c\n"; }
+
+=cut
+
+sub brace_expansion_1 {
+
+	my $str = shift || die "Error: String not set!\n";
+	print "IN: $str\n";
+
+	$str =~ /^(.*)\{(.*)\}(.*)/ || die "No braces in string!\n";
+	my ($a,$b,$c) = ($1,$2,$3);
+	my @ele = split(",",$b);
+
+	foreach my $e (@ele) {
+		print "$a $e $c\n";
+	}
+}
+
+# -----------------------------------------------------------------
+
+=head1 Task #1 - Brace expansion 2: Code compressed
+
+The second verion of brace expansion is only a compressed version written
+on two lines. I was not really able to make it a simple one-liner.
+
+ my ($a,$b,$c) = $ARGV[0] =~ /^(.*)\{(.*)\}(.*)/;
+ foreach my $e (split(",",$b)) { print "$a $e $c\n"; }
+
+The script is called with arg one "brace2"
+
+ ./pwc29.pl brace2 "Perl {Daily,Weekly,Monthly} Challenge"
+ Perl  Daily  Challenge
+ Perl  Weekly  Challenge
+ Perl  Monthly  Challenge
+
+=cut
+
+sub brace_expansion_2 {
+	my $str = shift || die "Error: String not set!\n";
+	my ($a,$b,$c) = $str =~ /^(.*)\{(.*)\}(.*)/;
+	foreach my $e (split(",",$b)) { print "$a $e $c\n"; }
+}
+
+# -----------------------------------------------------------------
+=head1 Task #1 and #2 - Brace expansion 3: C Inline
+
+The "Inline" Perl Module offers an easy way to call a C function from Perl.
+To learn about it use perldoc:
+
+ # perldoc Inline
+
+=head2 C-Code for Inline
+
+So first I wrote the "brex()" function in C. Then I called the C function with the use
+of the Inline Module. Here I had some difficulties, beside the difficulties I
+had with too low C knowledge. My C code must be in a BEGIN{} section to be available
+at perl compile time. And within my C code are backslashes that needed to be masked
+with an extra backslash. I.e. '\0' becomes '\\0' or 'printf("%s %s %s\n", a, tmp, c);'
+becomes 'printf("%s %s %s\\n", a, tmp, c);'
+
+ my $code_sub;
+ BEGIN {
+	$code_sub = <<END_C_SUB;
+
+ void without_braces (char* str, char* res) { 
+	int len = strlen(str)-2;
+	strncpy(res,str+1,len);
+	*(res+len)   = ',';
+	*(res+len+1) = '\\0';
+ }
+
+ void brex(char* a, char* b, char* c) {
+	char list[50];			// String without curly braces and extra comma
+	without_braces(b,list);
+
+	char* ref  = list;
+	char* nref = strchr(ref,',');
+	int   pos=0;
+	do {
+		char tmp[20];
+		pos = nref - ref;
+
+		strncpy(tmp,ref,pos);
+		printf("%s %s %s\\n", a, tmp, c);
+		ref += pos+1;
+
+	} while ((nref = strchr(ref,',')) != NULL);
+ }
+ END_C_SUB
+ }
+
+=head2 Perl Code with Inline
+
+The "use Inline" is compiling the C-Code. Afterwards the C function can
+be called in Perl. The "Inline" module seems also to create XS code for me.
+When you look into the "_Inline/" folder you can see the created temporary
+files.
+
+ use Inline C => $code_sub;
+ my ($a,$b,$c) = $ARGV[0] =~ /^(.*)(\{.*\})(.*)/;
+ brex($a,$b,$c);
+
+Now I can execute the program:
+
+ ./pwc29.pl brace3 "Perl {Daily,Weekly,Monthly} Challenge"
+ Perl  Daily  Challenge
+ Perl  Weekly  Challenge
+ Perl  Monthly  Challenge
+
+=cut
+
+my $code_sub;
+
+BEGIN {
+	$code_sub = <<END_C_SUB;
+
+void without_braces (char* str, char* res) { 
+	int len = strlen(str)-2;
+	strncpy(res,str+1,len);
+	*(res+len)   = ',';
+	*(res+len+1) = '\\0';
+}
+
+void brex(char* a, char* b, char* c) {
+	char list[50];			// String without curly braces and extra comma
+	without_braces(b,list);
+
+	char* ref  = list;
+	char* nref = strchr(ref,',');
+	int   pos=0;
+	do {
+		char tmp[20];
+		pos = nref - ref;
+
+		strncpy(tmp,ref,pos);
+		printf("%s %s %s\\n", a, tmp, c);
+		ref += pos+1;
+
+	} while ((nref = strchr(ref,',')) != NULL);
+}
+END_C_SUB
+}
+
+use Inline C => $code_sub;
+
+sub brace_expansion_3 {
+	my $str = shift || die "Error: String not set!\n";
+	my ($a,$b,$c) = $str =~ /^(.*)(\{.*\})(.*)/;
+	brex($a,$b,$c);
+}
+
+# -----------------------------------------------------------------
+=head1 Task #1 and #2 - Brace expansion 4: External C program system call
+
+This is about an external C library used within Perl with XS code.
+I start this with writing the previous C code to file and compile
+it as C executable "brex" and C shared library brex.so. And I verify
+if the external program "brex" is executed properly.
+
+ # ./pwc29.pl brace4 "Perl {Daily,Weekly,Monthly} Challenge"
+ Command: gcc -fPIC -c tmp/brex.c -o tmp/brex.o
+ Command: gcc tmp/brex.o -o tmp/brex
+ Command: gcc -shared tmp/brex.o -L/usr/local/lib -o tmp/libbrex.so
+ Command: tmp/brex Perl  "{Daily,Weekly,Monthly}"  Challenge
+ IN: 4 - tmp/brex Perl {Daily,Weekly,Monthly} Challenge
+ Perl Daily Challenge
+ Perl Weekly Challenge
+ Perl Monthly Challenge
+
+=head2 The C Code for main()
+
+A C program needs the main() function. This main function is stored in a perl
+variable. The code must be available during perl compile time, so it is surrounded
+by a BEGIN {} block. The main() function is only calling the brex() function
+that we discussed in the former chapter.
+
+ my $code_main;
+
+ BEGIN {
+	$code_main = <<END_C_MAIN;
+
+ #include <stdio.h>
+ #include <string.h>
+
+ void brex(char*,char*,char*);
+
+ int main( int argc, char** argv ) {
+	printf("IN: %d - %s %s %s %s\\n",argc, argv[0], argv[1], argv[2], argv[3]);
+	brex(argv[1],argv[2],argv[3]);
+ }
+ END_C_MAIN
+ }
+
+=head2 The Perl code with system call
+
+A system call with perl function "qx()" is used to compile the
+C code and to call the resulting "brex" program. In the C code before
+we needed to mask the backslash. Now we have to substitute the backslash
+again. Why? Because otherwise the code is not working. Try and Error.
+
+I also do this to create an external C shared library for the XS trial below.
+
+C Code from $code_main and $code_sub is written to tmp/brex.c
+
+gcc creates tmp/brex.o, tmp/brex, tmp/libbrex.so
+
+C program is executed with command:
+ tmp/brex Perl "{Daily,Weekly,Monthly}" Challenge
+
+
+ my $LIB1= "/usr/local/lib";
+
+ sub brace_expansion_4 {
+	my $str = shift || die "Error: String not set!\n";
+	my ($a,$b,$c) = $str =~ /^(.*)(\{.*\})(.*)/;
+
+	# ------ Write C code to file ----------
+	open(my $fh, ">tmp/brex.c") or die "Error: Cant open brex.c!\n";
+	$code_sub =~ s/\\\\/\\/g;
+	$code_main =~ s/\\\\/\\/g;
+	print $fh "$code_main\n$code_sub\n";
+	close $fh;
+	
+	my @com = (
+		"gcc -fPIC -c tmp/brex.c -o tmp/brex.o",
+		"gcc tmp/brex.o -o tmp/brex",
+		"gcc -shared tmp/brex.o -L$LIB1 -o tmp/libbrex.so",
+		"tmp/brex $a \"$b\" $c",
+	);
+	foreach my $c (@com) { print "Command: $c\n"; my $ret = qx[$c]; print $ret; }
+ }
+
+=cut
+
+my $code_main;
+
+BEGIN {
+	$code_main = <<END_C_MAIN;
+
+#include <stdio.h>
+#include <string.h>
+
+void brex(char*,char*,char*);
+
+int main( int argc, char** argv ) {
+	printf("IN: %d - %s %s %s %s\\n",argc, argv[0], argv[1], argv[2], argv[3]);
+	brex(argv[1],argv[2],argv[3]);
+}
+END_C_MAIN
+}
+
+my $LIB1= "/usr/local/lib";
+
+sub brace_expansion_4 {
+	my $str = shift || die "Error: String not set!\n";
+	my ($a,$b,$c) = $str =~ /^(.*)(\{.*\})(.*)/;
+
+	# ------ Write C code to file ----------
+	open(my $fh, ">tmp/brex.c") or die "Error: Cant open brex.c!\n";
+	$code_sub =~ s/\\\\/\\/g;
+	$code_main =~ s/\\\\/\\/g;
+	print $fh "$code_main\n$code_sub\n";
+	close $fh;
+	
+	my @com = (
+		"gcc -fPIC -c tmp/brex.c -o tmp/brex.o",
+		"gcc tmp/brex.o -o tmp/brex",
+		"gcc -shared tmp/brex.o -L$LIB1 -o tmp/libbrex.so",
+		"tmp/brex $a \"$b\" $c",
+	);
+	foreach my $c (@com) { print "Command: $c\n"; my $ret = qx[$c]; print $ret; }
+}
+
+# -----------------------------------------------------------------
+=head1 Task #1 and #2 - Brace expansion 5: C code with XS
+
+We use our external library libbrex.so for the Perl Module Brex.pm.
+So we write a XS file "Brex.xs" that calls the brex() function from
+our libbrex.so library. The Brex.pm is dynamically loading the Brex.so
+library that was created from the Brex.xs file.
+
+Because this is a not very easy thing, and I also do not know much about
+it, it is better to investigate in the appropriate XS docu:
+
+ # perldoc perlxs
+ # perldoc perlxstut
+ # perldoc Module::Load::Conditional
+
+=cut
+
+my ($code_module,$code_xs);
+
+=head2 Perl XS file
+
+Here the XS code is stored in a perl variable. In the following program
+this is written to the file "tmp/Brex.xs". The XS code is for translating
+perl data types to C data types and vice versa. This is done by the "xsubpp",
+the "XS subroutine pre-processor".
+
+Here we state the C brex() function from our formerly created external libbrex.so
+and the input and output variables. The "template" is used to translate the vars.
+
+ $code_xs =<<CODE_XS_END;
+ #define PERL_NO_GET_CONTEXT
+ #include "EXTERN.h"
+ #include "perl.h"
+ #include "XSUB.h"
+ #include "ppport.h"
+ extern void brex(char*,char*,char*);
+ MODULE = Brex             PACKAGE = Brex
+ PROTOTYPES: ENABLE
+ void 
+ brex(a,b,c)
+ 	char* a
+ 	char* b
+ 	char* c
+ CODE_XS_END
+
+=cut
+
+$code_xs =<<CODE_XS_END;
+#define PERL_NO_GET_CONTEXT
+#include "EXTERN.h"
+#include "perl.h"
+#include "XSUB.h"
+#include "ppport.h"
+extern void brex(char*,char*,char*);
+MODULE = Brex             PACKAGE = Brex
+PROTOTYPES: ENABLE
+void 
+brex(a,b,c)
+	char* a
+	char* b
+	char* c
+CODE_XS_END
+
+=head2 Perl Module with XS Loader
+
+Here the Perl Module code for XS is stored in a perl variable. In the following program
+this is written to the file "tmp/Brex.pm". This code is loading the Brex.so interface
+library.
+
+ $code_module =<<CODE_MOD_END;
+ package Brex;
+ 
+ require Exporter;
+ our \@ISA = qw(Exporter);
+ our \@EXPORT = qw( );
+ our \$VERSION = '0.01';
+ 
+ require XSLoader;
+ XSLoader::load('Brex', \$VERSION);
+ 
+ 1;
+ CODE_MOD_END
+
+=cut
+
+
+$code_module =<<CODE_MOD_END;
+package Brex;
+
+require Exporter;
+our \@ISA = qw(Exporter);
+our \@EXPORT = qw( );
+our \$VERSION = '0.01';
+
+require XSLoader;
+XSLoader::load('Brex', \$VERSION);
+
+# Preloaded methods go here.
+1;
+CODE_MOD_END
+
+
+my $INC1= "/usr/lib/x86_64-linux-gnu/perl/5.24/CORE";
+my $INC2= "/usr/local/include";
+my $INC3= "/usr/local/lib/x86_64-linux-gnu/perl/5.24.1/PDL/Core";
+my $PP  = "/usr/local/bin/xsubpp";
+my $TM  = "/usr/share/perl/5.24.1/ExtUtils/typemap";
+
+=head2 Creation of XS Module Brex.pm
+
+The tools gcc and xsubpp are executed with perl system calls with
+the function "qx()". So the arg "brace5" is only for writing the file
+"tmp/Brex.pm" and "tmp/Brex.xs" and for compiling the XS code.
+
+ my $INC1= "/usr/lib/x86_64-linux-gnu/perl/5.24/CORE";
+ my $INC2= "/usr/local/include";
+ my $INC3= "/usr/local/lib/x86_64-linux-gnu/perl/5.24.1/PDL/Core";
+ my $PP  = "/usr/local/bin/xsubpp";
+ my $TM  = "/usr/share/perl/5.24.1/ExtUtils/typemap";
+
+ sub brace_expansion_5 {
+	my $str = shift || die "Error: String not set!\n";
+	my ($a,$b,$c) = $str =~ /^(.*)(\{.*\})(.*)/;
+
+	# ------ Write  code to file ----------
+	open(my $fh, ">tmp/Brex.pm") or die "Error: Cant open tmp/Brex.pm!\n";
+	print $fh "$code_module\n";
+	close $fh;
+	open($fh, ">tmp/Brex.xs") or die "Error: Cant open tmp/Brex.xs!\n";
+	print $fh "$code_xs\n";
+	close $fh;
+
+	my @com = (
+		"perl $PP -typemap $TM tmp/Brex.xs > tmp/Brex.xsc",
+		"mv tmp/Brex.xsc tmp/Brex.c",
+		"gcc -fPIC -I$INC1 -I$INC2 -I$INC3 -c tmp/Brex.c -o tmp/Brex.o",
+		"gcc -shared -L$LIB1 -L. -lbrex tmp/Brex.o -o tmp/libBrex.so",
+	);
+	foreach my $c (@com) { print "$c\n"; my $ret = qx[$c]; print $ret; }
+ }
+=cut
+
+sub brace_expansion_5 {
+	my $str = shift || die "Error: String not set!\n";
+	my ($a,$b,$c) = $str =~ /^(.*)(\{.*\})(.*)/;
+
+	# ------ Write  code to file ----------
+	open(my $fh, ">tmp/Brex.pm") or die "Error: Cant open tmp/Brex.pm!\n";
+	print $fh "$code_module\n";
+	close $fh;
+	open($fh, ">tmp/Brex.xs") or die "Error: Cant open tmp/Brex.xs!\n";
+	print $fh "$code_xs\n";
+	close $fh;
+
+	my @com = (
+		"perl $PP -typemap $TM tmp/Brex.xs > tmp/Brex.xsc",
+		"mv tmp/Brex.xsc tmp/Brex.c",
+		"gcc -fPIC -I$INC1 -I$INC2 -I$INC3 -c tmp/Brex.c -o tmp/Brex.o",
+		"gcc -shared -L$LIB1 -Ltmp -lbrex tmp/Brex.o -o tmp/libBrex.so",
+	);
+	foreach my $c (@com) { print "Command: $c\n"; my $ret = qx[$c]; print $ret; }
+}
+
+=head2 Usage of Brex.pm
+
+Before we created the C-Code XS Module Brex.pm, now we use it.
+We simply call the Perl function "Brex::brex($a,$b,$c)". The only
+difficulty here is the "use Brex.pm" statement. We can not use it here
+because otherwise we get a compile error, when Brex.pm is not created before.
+And this is the case here, because this same script shall create it.
+So here the Module "Module::Load::Conditional" with its funcion "can_load()"
+is used.
+
+In the BEGIN block the LD_LIBRARY_PATH must be set. It also can be set
+in the shell before executing this script.
+
+ BEGIN {
+	$ENV{LD_LIBRARY_PATH}="tmp";
+	my $ret = qx[ echo \$LD_LIBRARY_PATH; export \$LD_LIBRARY_PATH ];
+	print "ENV: $ret\n";
+ }
+
+ sub brace_expansion_6 {
+	my $str = shift || die "Error: String not set!\n";
+	my ($a,$b,$c) = $str =~ /^(.*)(\{.*\})(.*)/;
+
+	use lib 'tmp';
+
+	# --- Conditional execution, if module can be loaded
+	if(my $ret = require "Brex.pm") { Brex::brex($a,$b,$c); }
+	else { die "Error: Perl Module tmp/Brex.pm not available ($ret)!\n"; }
+
+	# --- Conditional execution, if module can be loaded
+	# this somehow did NOT work:
+	use Module::Load::Conditional qw[can_load];
+	if(can_load(modules=>"Brex")) {
+		Brex::brex($a,$b,$c);
+	}
+	else { die "Error: Perl Module tmp/Brex.pm not available!\n"; }
+ }
+
+=head2 Executing XS code
+
+The XS code ist executed. The LD_LIBRARY_PATH is now also set in the code of
+this script in a BEGIN block, see above. So this export statement is not necessary.
+
+ # export LD_LIBRARY_PATH=tmp
+ # ./pwc29.pl brace6 "Perl {Daily,Weekly,Monthly} Challenge"
+ ENV: tmp
+
+ Perl  Daily  Challenge
+ Perl  Weekly  Challenge
+ Perl  Monthly  Challenge
+
+=cut
+
+sub brace_expansion_6 {
+	my $str = shift || die "Error: String not set!\n";
+	my ($a,$b,$c) = $str =~ /^(.*)(\{.*\})(.*)/;
+
+	use lib 'tmp';
+
+	# use Brex;
+	# Brex::brex($a,$b,$c);
+
+	if(my $ret = require "Brex.pm") { Brex::brex($a,$b,$c); }
+	else { die "Error: Perl Module tmp/Brex.pm not available ($ret)!\n"; }
+
+	# use Module::Load::Conditional qw[can_load];
+	# if(can_load(modules=>"lib/Brex.pm")) {
+	# 	Brex::brex($a,$b,$c);
+	# }
+	# else { die "Error: Perl Module tmp/Brex.pm not available!\n"; }
+}
+
+# --------------------------------------------------
+
+if($ARGV[0] eq "html") { create_html(); }
+elsif($ARGV[0] eq "brace1") { brace_expansion_1($ARGV[1]); }
+elsif($ARGV[0] eq "brace2") { brace_expansion_2($ARGV[1]); }
+elsif($ARGV[0] eq "brace3") { brace_expansion_3($ARGV[1]); }
+elsif($ARGV[0] eq "brace4") { brace_expansion_4($ARGV[1]); }
+elsif($ARGV[0] eq "brace5") { brace_expansion_5($ARGV[1]); }
+elsif($ARGV[0] eq "brace6") { brace_expansion_6($ARGV[1]); }
+
+# --------------------------------------------------
+
+=head1 AUTHOR
+
+chuck
+
+=cut
+
+
diff --git a/challenge-029/burkhard-nickels/perl5/ch-2.pl b/challenge-029/burkhard-nickels/perl5/ch-2.pl
new file mode 100644
index 0000000000..f2ce667ddd
--- /dev/null
+++ b/challenge-029/burkhard-nickels/perl5/ch-2.pl
@@ -0,0 +1,663 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+my $tmp = "tmp";
+if(!-d $tmp) { 
+	mkdir $tmp;
+	print "Created folder $tmp!\n";
+	# die "Error: Folder tmp/ does not exist!"; 
+}
+
+BEGIN {
+	$ENV{LD_LIBRARY_PATH}="tmp";
+	my $ret = qx[ echo \$LD_LIBRARY_PATH; export \$LD_LIBRARY_PATH ];
+	print "ENV: $ret\n";
+}
+
+# --------------------------------------------------
+my $bn = "pwc29";
+my $title = "Perl Weekly Challenge #029";
+
+my $css = <<END_CSS;
+body { margin-left:auto; margin-right:auto; width:80%; }
+h1   { border-bottom:4px solid red; }
+h2   { border-bottom:2px solid orange; }
+pre  { border:2px solid grey; background-color:#eef; padding:10px; }
+li   { padding:5px; }
+a    { text-decoration:none; color:black; padding:4px; }
+a:hover { background-color: brown; color:white; }
+._podblock_ { width:100%; background-color:black; color:white; padding:10px; }
+END_CSS
+
+
+sub create_html {
+	print "Create Web ...\n";
+	open(my $fh,">$bn.css") or die "Cant open $bn.css!\n";
+	print $fh $css;
+	close $fh;
+	print "\t$bn.css created!\n";
+	my $ret = qx[pod2html --header --title="$title" --css=$bn.css $bn.pl > $bn.html];
+	print "\t$bn.html created!\n";
+}
+
+
+# --------------------------------------------------
+=head1 Perl Weekly Challenge #029 
+
+I want to try the Perl Weekly Challenge. During I am working on it, I get
+more and more ideas what to do next. So I decided to put all of the work in
+only one file. The result is this one and only file "pwd29.pl" for several solutions.
+
+The tasks for my first Perl Weekly Challenge are:
+
+Task #1: Write a script to demonstate brace expansion.
+
+Task #2: Write a script to demonstate calling a C function.
+
+=head1 In brief
+
+Cite from the Song "Ich weiss was ich will" from Udo Juergens: 
+"Ich hab noch nie in meinem Leben Berge versetzt, ich tu'es jetzt."
+(chuck, 12.10.2019)
+
+I will do the following trials:
+
+=over 4
+
+=item * Task #1 and #2, Documentation on PWC
+
+I created an inline documentation in POD format. With arg "html" pod2html is
+executed to convert the POD to HTML. The files "pwc29.css" and "pwc29.html"
+are created.
+
+ # perldoc pwc29.pl
+   or
+ # ./pwc29.pl html
+
+=item * Task #1, Brace expansion 1: Pattern matching and split
+
+ # ./pwc29.pl brace1 "Perl {Daily,Weekly,Monthly} Challenge"
+
+=item * Task #1, Brace expansion 2: Code compressed
+
+ # ./pwc29.pl brace1 "Perl {Daily,Weekly,Monthly} Challenge"
+
+=item * Task #1 and #2, Brace expansion 3: C Inline
+
+The C function brex() is created and used with the "Inline" module.
+
+ # ./pwc29.pl brace3 "Perl {Daily,Weekly,Monthly} Challenge"
+
+=item * Task #1 and #2, Brace expansion 4: External C program system call
+
+The main C function is created and written to file "brex.c" together with
+the former created "brex()" function. Than the C program "brex" and C library
+libbrex.so are created with gcc.
+
+ # ./pwc29.pl brace4 "Perl {Daily,Weekly,Monthly} Challenge"
+
+=item * Task #1 and #2, Brace expansion 5 and 6; C-Code with XS
+
+The Brex.pm Perl Module with XS-Loader and the Brex.xs file to create
+the interface module are created with arg "brace5". With arg "brace6"
+the new Perl XS code is executed.
+
+ # ./pwc29.pl brace5 "Perl {Daily,Weekly,Monthly} Challenge"
+	and
+ # ./pwc29.pl brace6 "Perl {Daily,Weekly,Monthly} Challenge"
+
+=back
+
+=cut
+
+# -----------------------------------------------------------------
+=head1 Task #1 - Brace expansion 1: Pattern matching and split
+
+Also the shell is doing brace expansion, so I need to put the whole
+string in double quotes.
+
+ ./pwc29.pl brace1 "Perl {Daily,Weekly,Monthly} Challenge"
+ IN: Perl {Daily,Weekly,Monthly} Challenge
+ Perl  Daily  Challenge
+ Perl  Weekly  Challenge
+ Perl  Monthly  Challenge
+
+The perl script is only doing pattern matching and split the list
+of comma separated strings.
+
+ my $str = $ARGV[0] || die "Error: String not set!\n";
+ print "IN: $str\n";
+
+ $str =~ /^(.*)\{(.*)\}(.*)/ || die "No braces in string!\n";
+ my ($a,$b,$c) = ($1,$2,$3);
+ my @ele = split(",",$b);
+
+ foreach my $e (@ele) { print "$a $e $c\n"; }
+
+=cut
+
+sub brace_expansion_1 {
+
+	my $str = shift || die "Error: String not set!\n";
+	print "IN: $str\n";
+
+	$str =~ /^(.*)\{(.*)\}(.*)/ || die "No braces in string!\n";
+	my ($a,$b,$c) = ($1,$2,$3);
+	my @ele = split(",",$b);
+
+	foreach my $e (@ele) {
+		print "$a $e $c\n";
+	}
+}
+
+# -----------------------------------------------------------------
+
+=head1 Task #1 - Brace expansion 2: Code compressed
+
+The second verion of brace expansion is only a compressed version written
+on two lines. I was not really able to make it a simple one-liner.
+
+ my ($a,$b,$c) = $ARGV[0] =~ /^(.*)\{(.*)\}(.*)/;
+ foreach my $e (split(",",$b)) { print "$a $e $c\n"; }
+
+The script is called with arg one "brace2"
+
+ ./pwc29.pl brace2 "Perl {Daily,Weekly,Monthly} Challenge"
+ Perl  Daily  Challenge
+ Perl  Weekly  Challenge
+ Perl  Monthly  Challenge
+
+=cut
+
+sub brace_expansion_2 {
+	my $str = shift || die "Error: String not set!\n";
+	my ($a,$b,$c) = $str =~ /^(.*)\{(.*)\}(.*)/;
+	foreach my $e (split(",",$b)) { print "$a $e $c\n"; }
+}
+
+# -----------------------------------------------------------------
+=head1 Task #1 and #2 - Brace expansion 3: C Inline
+
+The "Inline" Perl Module offers an easy way to call a C function from Perl.
+To learn about it use perldoc:
+
+ # perldoc Inline
+
+=head2 C-Code for Inline
+
+So first I wrote the "brex()" function in C. Then I called the C function with the use
+of the Inline Module. Here I had some difficulties, beside the difficulties I
+had with too low C knowledge. My C code must be in a BEGIN{} section to be available
+at perl compile time. And within my C code are backslashes that needed to be masked
+with an extra backslash. I.e. '\0' becomes '\\0' or 'printf("%s %s %s\n", a, tmp, c);'
+becomes 'printf("%s %s %s\\n", a, tmp, c);'
+
+ my $code_sub;
+ BEGIN {
+	$code_sub = <<END_C_SUB;
+
+ void without_braces (char* str, char* res) { 
+	int len = strlen(str)-2;
+	strncpy(res,str+1,len);
+	*(res+len)   = ',';
+	*(res+len+1) = '\\0';
+ }
+
+ void brex(char* a, char* b, char* c) {
+	char list[50];			// String without curly braces and extra comma
+	without_braces(b,list);
+
+	char* ref  = list;
+	char* nref = strchr(ref,',');
+	int   pos=0;
+	do {
+		char tmp[20];
+		pos = nref - ref;
+
+		strncpy(tmp,ref,pos);
+		printf("%s %s %s\\n", a, tmp, c);
+		ref += pos+1;
+
+	} while ((nref = strchr(ref,',')) != NULL);
+ }
+ END_C_SUB
+ }
+
+=head2 Perl Code with Inline
+
+The "use Inline" is compiling the C-Code. Afterwards the C function can
+be called in Perl. The "Inline" module seems also to create XS code for me.
+When you look into the "_Inline/" folder you can see the created temporary
+files.
+
+ use Inline C => $code_sub;
+ my ($a,$b,$c) = $ARGV[0] =~ /^(.*)(\{.*\})(.*)/;
+ brex($a,$b,$c);
+
+Now I can execute the program:
+
+ ./pwc29.pl brace3 "Perl {Daily,Weekly,Monthly} Challenge"
+ Perl  Daily  Challenge
+ Perl  Weekly  Challenge
+ Perl  Monthly  Challenge
+
+=cut
+
+my $code_sub;
+
+BEGIN {
+	$code_sub = <<END_C_SUB;
+
+void without_braces (char* str, char* res) { 
+	int len = strlen(str)-2;
+	strncpy(res,str+1,len);
+	*(res+len)   = ',';
+	*(res+len+1) = '\\0';
+}
+
+void brex(char* a, char* b, char* c) {
+	char list[50];			// String without curly braces and extra comma
+	without_braces(b,list);
+
+	char* ref  = list;
+	char* nref = strchr(ref,',');
+	int   pos=0;
+	do {
+		char tmp[20];
+		pos = nref - ref;
+
+		strncpy(tmp,ref,pos);
+		printf("%s %s %s\\n", a, tmp, c);
+		ref += pos+1;
+
+	} while ((nref = strchr(ref,',')) != NULL);
+}
+END_C_SUB
+}
+
+use Inline C => $code_sub;
+
+sub brace_expansion_3 {
+	my $str = shift || die "Error: String not set!\n";
+	my ($a,$b,$c) = $str =~ /^(.*)(\{.*\})(.*)/;
+	brex($a,$b,$c);
+}
+
+# -----------------------------------------------------------------
+=head1 Task #1 and #2 - Brace expansion 4: External C program system call
+
+This is about an external C library used within Perl with XS code.
+I start this with writing the previous C code to file and compile
+it as C executable "brex" and C shared library brex.so. And I verify
+if the external program "brex" is executed properly.
+
+ # ./pwc29.pl brace4 "Perl {Daily,Weekly,Monthly} Challenge"
+ Command: gcc -fPIC -c tmp/brex.c -o tmp/brex.o
+ Command: gcc tmp/brex.o -o tmp/brex
+ Command: gcc -shared tmp/brex.o -L/usr/local/lib -o tmp/libbrex.so
+ Command: tmp/brex Perl  "{Daily,Weekly,Monthly}"  Challenge
+ IN: 4 - tmp/brex Perl {Daily,Weekly,Monthly} Challenge
+ Perl Daily Challenge
+ Perl Weekly Challenge
+ Perl Monthly Challenge
+
+=head2 The C Code for main()
+
+A C program needs the main() function. This main function is stored in a perl
+variable. The code must be available during perl compile time, so it is surrounded
+by a BEGIN {} block. The main() function is only calling the brex() function
+that we discussed in the former chapter.
+
+ my $code_main;
+
+ BEGIN {
+	$code_main = <<END_C_MAIN;
+
+ #include <stdio.h>
+ #include <string.h>
+
+ void brex(char*,char*,char*);
+
+ int main( int argc, char** argv ) {
+	printf("IN: %d - %s %s %s %s\\n",argc, argv[0], argv[1], argv[2], argv[3]);
+	brex(argv[1],argv[2],argv[3]);
+ }
+ END_C_MAIN
+ }
+
+=head2 The Perl code with system call
+
+A system call with perl function "qx()" is used to compile the
+C code and to call the resulting "brex" program. In the C code before
+we needed to mask the backslash. Now we have to substitute the backslash
+again. Why? Because otherwise the code is not working. Try and Error.
+
+I also do this to create an external C shared library for the XS trial below.
+
+C Code from $code_main and $code_sub is written to tmp/brex.c
+
+gcc creates tmp/brex.o, tmp/brex, tmp/libbrex.so
+
+C program is executed with command:
+ tmp/brex Perl "{Daily,Weekly,Monthly}" Challenge
+
+
+ my $LIB1= "/usr/local/lib";
+
+ sub brace_expansion_4 {
+	my $str = shift || die "Error: String not set!\n";
+	my ($a,$b,$c) = $str =~ /^(.*)(\{.*\})(.*)/;
+
+	# ------ Write C code to file ----------
+	open(my $fh, ">tmp/brex.c") or die "Error: Cant open brex.c!\n";
+	$co