Re: Licensing code
On Fri, May 8, 2009 at 00:51, Steve Bertrand wrote: snip > I wish all of my code be free, ie: I don't care if a commercial entity > uses it for their benefit or not, I don't care if derivatives are used > in commercial products or not, all I really care about is that my > current code is protected so that it can not be "claimed" as anyone > elses, currently... if that makes sense. > > Am I allowed to put in any license I choose into files containing my own > code, so long as I honour all licences within any modules which I may > have included? > > If I do add a license into my files, does that take effect immediately? snip I can't speak for Canada, but in the US your first desire is handled by copyright law. The second you put pen to paper or fingers to keyboard your work is protected; however, you need to be able to prove that the work is yours. Due to the way copyright law works, no one has the right to copy or run your code without a license. This is why the GPL works. Your code is your own, and you can put any license on it that you want. So long as you are only including code via use, require, or the like, the licenses of the other modules will have no effect on you. Just make sure you have the right to distribute those modules (it is a requirement for being hosted on CPAN, so if you got the module there you should be fine). -- Chas. Owens wonkden.net The most important skill a programmer can have is the ability to read. -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Reading/writing binary
Hi Chas, On 5/7/09, Chas. Owens wrote: > You use pack to create a binary value and unpack to read a binary > value. So, to write a file containing three 32 bit integers you say [snip] Thanks for the sample code; that worked exactly as you said. I wasn't getting anywhere with google; I thought the key was to get it working with the b/B [bit string] templates...I wasn't close at all. :-) Thanks a lot! Ray -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Reading/writing binary
On Fri, May 8, 2009 at 03:20, Raymond Wan wrote: > Hi Chas, > > On 5/7/09, Chas. Owens wrote: >> You use pack to create a binary value and unpack to read a binary >> value. So, to write a file containing three 32 bit integers you say > > [snip] > > Thanks for the sample code; that worked exactly as you said. I wasn't > getting anywhere with google; I thought the key was to get it working > with the b/B [bit string] templates...I wasn't close at all. :-) > > Thanks a lot! > > Ray > The place to go is http://perldoc.perl.org, and in your case http://perldoc.perl.org/functions/pack.html and http://perldoc.perl.org/functions/unpack.html. You can also get these docs on your machine by saying perldoc -f pack perldoc -f unpack The key with pack and unpack is to use the right template character. In the example, I used l which will turn a Perl number in to a binary signed 32 bit integer. If I had wanted them to be unsigned I could have used L. The documentation for pack lists what the various templates are and what they do. The unpack function uses the same templates, but in reverse. -- Chas. Owens wonkden.net The most important skill a programmer can have is the ability to read. -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Reading/writing binary
Hi John, On 5/8/09, John W. Krahn wrote: [snip] > That is equivalent in C to: > > unsigned char decimal_number = 42; > > Or another way to write that in Perl is: > > my $decimal_number = pack 'C', 42; > > > Once you have created the appropriate strings using pack() then just > print() them. I see; thanks for the explanation. I never used Perl for bits before, so pack/unpack is still new to me. Until now, I just envisioned that everything happens magically behind the scenes for me. :-) At this moment, I got it to work by not opening a file for binary output. Instead, I just print () to STDOUT. It seems specifying whether the output file is binary or now doesn't matter? I thought it would... Thanks again! Ray -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Reading/writing binary
Hi Chas., On 5/8/09, Chas. Owens wrote: > The place to go is http://perldoc.perl.org, and in your case > http://perldoc.perl.org/functions/pack.html and > http://perldoc.perl.org/functions/unpack.html. You can also get these > docs on your machine by saying > > perldoc -f pack > perldoc -f unpack > > The key with pack and unpack is to use the right template character. > In the example, I used l which will turn a Perl number in to a binary > signed 32 bit integer. If I had wanted them to be unsigned I could > have used L. The documentation for pack lists what the various > templates are and what they do. The unpack function uses the same > templates, but in reverse. I see; thanks! I was reading perldoc on the Web; didn't realize a -f was required for the command line. It's quite clear it's needed if I had read the man pages of perldoc.. Thanks! Ray -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
RE: Licensing code
From: Steve Bertrand > Chas. Owens wrote: >> On Thu, May 7, 2009 at 22:04, Steve Bertrand wrote: >> snip >>> I like the BSD license, and I am a BSD person, but I'm asking for >>> feedback from the creme-de-la-creme with regards to making code public, >>> so that I can put something in my code to ensure that someone else >>> doesn't decide that they want to "claim" it. >> snip >> >> Given your desire to keep the code free (i.e. not allow people to >> create closed source forks), your best option is the GPLv2[1] or >> GPLv3[2] licenses. Perl itself and many of its modules are dual >> licensed under GPLv1[3] or later license and the Artistic License[4]. >> >> The GPL basically says that you must provide the source code in the >> preferred form to people you give or sell the binaries to (if they ask >> for it). >> >> The Artistic License is similar, but a bit more free (the GPL gets a >> bit hinky when you want to combine GPL and commercial code). > > [snip] > > Thanks Chas, for the response. > > I'm a network engineer, naturally, I hate legal stuff. Given what you've > said, I'll rephrase: > > I wish all of my code be free, ie: I don't care if a commercial entity > uses it for their benefit or not, I don't care if derivatives are used > in commercial products or not, all I really care about is that my > current code is protected so that it can not be "claimed" as anyone > elses, currently... if that makes sense. > > Am I allowed to put in any license I choose into files containing my own > code, so long as I honour all licences within any modules which I may > have included? > > If I do add a license into my files, does that take effect immediately? You are talking about two different states Steve, and they are mutually exclusive. First off, public domain is not a license, it is a specific condition that is exempt from licensing. It means it is totally free of all copy rights. You simply put a statement into the file that says you release this file into the public domain and it is done. Once you release it, you have given it away and there is no way to get control back. It takes effect as soon as you make the marked file publicly accessible. You can see Bob Stout's Snippets site for examples. If you do want to retain some modicum of control, then you need to select a license. That is when you would get into the discussion between free software and open source. But it sounds like you prefer the public domain option. Bob McConnell -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Reading/writing binary
Raymond Wan wrote: On 5/8/09, John W. Krahn wrote: [snip] That is equivalent in C to: unsigned char decimal_number = 42; Or another way to write that in Perl is: my $decimal_number = pack 'C', 42; Once you have created the appropriate strings using pack() then just print() them. I see; thanks for the explanation. I never used Perl for bits before, so pack/unpack is still new to me. Until now, I just envisioned that everything happens magically behind the scenes for me. :-) At this moment, I got it to work by not opening a file for binary output. Instead, I just print () to STDOUT. It seems specifying whether the output file is binary or now doesn't matter? I thought it would... That depends on the operating system you are using. I use Linux so there is no difference between "binary" and "text", except for those specific applications that can't handle "binary" data. If you are on a system like DOS/Windows then reading or writing "binary" data as "text" will cause problems because line ending translation occurs with "text" files but not with "binary" files. John -- Those people who think they know everything are a great annoyance to those of us who do.-- Isaac Asimov -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: newbie needs help with first perl prog
Prince Mavi wrote:
Hi folks
Hello,
I am new to perl. this is my first real program in perl.
The program is not doing what i intend it to do.
The problem in nut shell is that:
I expect to see the menu first and then input my choice.
but
the program asks for my choice first and then displays the menu
Please have a look and see what am i doing wrong.
Thanks a ton for your time guys.
code
--
#!/usr/bin/perl
use strict;
use warnings;
sub dispBlanks {
print "\n\n";
}
sub clrScr {
system("clear");
}
sub dispMenu {
clrScr;
print "\n\n=== Student Manage Pro ===\n";
print "1. Display all students\n";
print "2. Display a particular student\n";
print "3. Add a new student\n";
print "4. Delete a student\n";
print "0. Exit\n";
print "Please choose one of the options\n";
}
while (1) {
dispMenu
my $choice = ;
Your problem is here. You are calling the subroutine 'dispMenu' with
the argument 'my $choice = '. In order to pass the value of the
expression 'my $choice = ' to the subroutine 'dispMenu' the
expression must be evaluated first so you must provide an option before
the menu is displayed.
chomp($choice); # to remove newline
print "you chose $choice";
Once that is fixed then this line will only diplay for a tiny fraction
of a second as you loop around and clear the screen right away.
dispBlanks;
}
--
I would do it using strings instead of subroutines:
# #!/usr/bin/perl
use strict;
use warnings;
my $dispBlanks = "\n\n";
my $clrScr = `clear`;
my $dispMenu = <;
chomp $choice; # to remove newline
last if $choice == 0;
print "you chose $choice", $dispBlanks;
}
__END__
John
--
Those people who think they know everything are a great
annoyance to those of us who do.-- Isaac Asimov
--
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Re: Licensing code
> ""Chas" == "Chas Owens" writes: "Chas> Neither license prevents people from selling the software in question, "Chas> but both require that source be available (or made available), so "Chas> anyone charging an arm and a leg for it will rapidly find free "Chas> versions being made available (see CentOS and RedHat for an example). No, the Artistic license is much more like a MIT/BSD-style license, which basically permits the recipient of your work nearly every right you also have. The recipient is free to incorporate your work into their commercial product, and never share the source code of the derived work. Some of us consider this a Good Thing. Basically, GPL retains many rights to the author, making it an assymetric relationship, effectively distrusting any second or third or fourth party by making the originator a special case. The Artistic license gives away nearly every right to the recipients, equally trusting that they'll "do the right thing" more often than not. Think of the GPL as "socialism by force" and the Artistic as "socialism by choice". -- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Licensing code
On Fri, May 8, 2009 at 11:33, Randal L. Schwartz wrote: >> ""Chas" == "Chas Owens" writes: > > "Chas> Neither license prevents people from selling the software in question, > "Chas> but both require that source be available (or made available), so > "Chas> anyone charging an arm and a leg for it will rapidly find free > "Chas> versions being made available (see CentOS and RedHat for an example). > > No, the Artistic license is much more like a MIT/BSD-style license, which > basically permits the recipient of your work nearly every right you also > have. The recipient is free to incorporate your work into their commercial > product, and never share the source code of the derived work. Some of us > consider this a Good Thing. snip I missed option c when I skimmed it. 3. You may otherwise modify your copy of this Package in any way, provided that you insert a prominent notice in each changed file stating how and when you changed that file, and provided that you do at least ONE of the following: a) place your modifications in the Public Domain or otherwise make them Freely Available, such as by posting said modifications to Usenet or an equivalent medium, or placing the modifications on a major archive site such as uunet.uu.net, or by allowing the Copyright Holder to include your modifications in the Standard Version of the Package. b) use the modified Package only within your corporation or organization. c) rename any non-standard executables so the names do not conflict with standard executables, which must also be provided, and provide a separate manual page for each non-standard executable that clearly documents how it differs from the Standard Version. d) make other distribution arrangements with the Copyright Holder. -- Chas. Owens wonkden.net The most important skill a programmer can have is the ability to read. -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Perl code for comparing two files
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
Mr. Adhikary,
The following will take any number of files as arguments, in the format
you described (I even tested it! :-)). It goes through each line of
those files, stuffing (the relevant part of) each line in a 'seen' hash
(more on that, and other, hash techniques here if you're interested:
http://www.perl.com/pub/a/2006/11/02/all-about-hashes.html).
The code below does not keep track of line numbers as you requested, but
I think the hash technique used here could help you as you approach a
solution to your particular problem.
#!/usr/bin/perl
use strict;
use warnings;
use File::Slurp; # This is where 'read_file' lives
my %seen;
for my $arg ( @ARGV ) {
my @lines = read_file( $arg );
for my $line ( @lines ) {
chomp $line;
my @elems = split / /, $line;
my $value = $elems[1];
$seen{$value}++;
}
}
for my $k ( keys %seen ) {
print $k, "\n" if $seen{$k} > 1;
}
Regards,
Rich Loveland
Anirban Adhikary wrote:
> Hi List
> I am writing a perl code which will takes 2 more files as argument. Then It
> will check the the values of each line of a file with respect with another
> file. If some value matches then it will write the value along with line
> number to another ( say outputfile) file.
>
> The source files are as follow
>
> Contents of abc.txt
> 1 2325278241,P0
> 2 2296250723,MH
> 3 2296250724,MH
> 4 2325277178,P0
> 5 7067023316,WL
> 6 7067023329,WL
> 7 2296250759,MH
> 8 7067023453,WL
> 9 7067023455,WL
> 10 555413,EA05
> ###
> Contents of xyz.txt
> 1 7067023453,WL
> 2 31-DEC-27,2O,7038590671
> 3 31-DEC-27,2O,7038596464
> 4 31-DEC-27,2O,7038596482
> 5 2296250724,MH
> 6 31-DEC-27,2O,7038597632
> 7 31-DEC-27,2O,7038589511
> 8 31-DEC-11,2O,7038590671
> 9 7067023455,WL
> 10 31-DEC-27,2O,7038555744
> ###
> Contents of pqr.txt
> 1 2325278241,P0
> 2 7067023316,WL
> 3 7067023455,WL
> 4 2296250724,MH
>
>
>
>
>
>
> For this requirement I have written the following code which works fine for
> 2 input files
>
> use strict;
> use warnings;
>
> use Benchmark;
>
> if(@ARGV < 2) {
> print "Please enter atleast two or more .orig file names \n";
> exit 0;
> }
> my @file_names = @ARGV;
> chomp(@file_names);
> my @files_to_process;
>
> for(@file_names) {
> if( -s $_){
> print "File $_ exists\n";
> push(@files_to_process,$_);
> }
> elsif( -e $_) {
> print "File $_ exists but it has zero byte size\n";
> }
> else {
> print "File $_ does not exists \n";
> }
> }
>
> my $count = @files_to_process;
> if( $count < 2 ) {
> print "Atleast 2 .orig files are required to continue this
> program\n";
> exit 0;
> }
>
> my $output_file = "outputfile";
> my $value = 0;
> my $start_time = new Benchmark;
>
>
> if( $count >= 2 ) {
> while ($count) {
> my ($files_after_processing_pointer,$return_val) =
> create_itermediate_file (\...@files_to_process,$value);
> my @files_after_processing =
> @$files_after_processing_pointer;
> $count = @files_after_processing;
> $value = $return_val;
> @files_to_process = @files_after_processing;
>
> }
>
> my $end_time = new Benchmark;
> my $difference = timediff($end_time, $start_time);
> print "It took ", timestr($difference), " to execute the program\n";
>
> }
>
>
>
>
> sub create_itermediate_file {
> my $file_pointer = $_[0];
> my $counter = $_[1];
> my @file_content = @$file_pointer;
>
> if($counter == 0) {
> my($first_file,$second_file) = splice
> (@file_content, 0, 2);
> open my $orig_first, "<", $first_file
> or die "could not open $first_file: $!";
> open my $orig_second, "<", $second_file
> or die "could not open $second_file:
> $!";
> open my $output_fh, ">", $output_file
> or die "could not open $output_file:
> $!";
>
> my %content_first;
> while (my $line = <$orig_first>) {
> chomp $line;
> if ($line) {
>
> my($line_num,$value) = split(" ",$line);
>
> $content_first{$value} = $line_num;
> }
> }
>
> my %content_second;
> w
