Feedback and Hints, January 2003.

If you have a question regarding any of the articles in this journal, or some comments please send them in. If there are any general questions about Unix or Database Administration, I will attempt to answer them.

Feedback:

Text file of user agent strings.
Calling the fm script from another CGI script.

Hints for this month:

Activate text links with w3m.

Text file of user agent strings.

Date: Sat, 11 Jan 2003 03:43:25 +1100

Hi, I think your lists of http_user_agent strings is very useful. Only
thing is, is that I am having difficulty importing them into a lookup
table from HTML format. Is there any way I can download an ASCII
delimited text file, with the 2 columns of data?

David Perry
USA (?)

This is something that I had intended to do. But I did not get around to
doing it. I have added two text files browser_list and robots_list.
These files are tab-delimited ASCII and are created when the other lists
are updated.

Calling the fm script from another CGI script.

Date: Sun, Dec 29, 2002
Gerry,

Thank you very much for writing fm.pl, and its accompanying article
'Formatting Text with Perl.' It's just what I need and is the best
formatter I've found.

Question: How to pass it a string instead of it taking its input from a
file?

Brian Hauk
Vancouver, BC
Canada


Date: Mon, Jan 12, 2003
Brian,

I have been away on holiday for the past three weeks, which I spent at a
little coastal town called Mallacoota (on the border between NSW and
VIC). It was an excellant break and I never even looked at computer. So
that is why I did not answer your e-mail.

Can you tell me if your question relates to using the script in Unix or
Windows?

Gerry Patterson


Date: Mon, Jan 13, 2003

Hi Gerry,

Thanks for your reply. Glad to hear you had an excellent break, but I'm
surprised you survived without a computer. Regarding fm.pl, I'm now using
another less sophisticated formatting script found on the web, but am
curious to see how to modify yours to accept a string variable.

What I found is the following:

++++++++++++++++++++++++++++++++++++++++++

#!/usr/bin/perl -w
# wrapit.pl - works!

require 5.0.0;          # require Perl version 5.0 and above
use strict;
use warnings;
use diagnostics;

use Text::Wrap;

print createArticleBody();

sub createArticleBody # create
{
my $new_body;
my @wrapped_body;

$Text::Wrap::columns = 72;

my @article_body = <<HERE_TARGET;

We at UPSERJ (an anti poverty anti racist group here in Suburban NYC)
need a
wee bit of CGI or Perl scripting for UPSERJ.org. We have an anti-police
brutality project going on over at http://upserj.org.

We want the site to be able to take in a police brutality incident
report.

HERE_TARGET

# wrap lines and convert to string

@wrapped_body = Text::Wrap::wrap('', '', @article_body);

$new_body = join '', @wrapped_body;

return $new_body;
}

++++++++++++++++++++++++++++++++++++++++++

Regards,

Brian


G'day Brian.

It's not really a holiday if I take a computer ... It was good to read
some books and relax in the shade.

Anyway, I checked your site. I must confess I am not familiar with Zeus 3.4.
If this is a Unix operating system, you could use the script as is, by
invoking it as a command. I actually designed it for use on the fly
within vi (In fact that is how I am writing this e-mail right now). This
is why it accepts input from stdin as well as the command line. So you
could use the existing script inside your CGI script using code like:

	my $length;
	my $tmpstr;

	# set these variables somewhere ... blah blah blah
	# assume that the script fm resides in /usr/local/bin/fm

	chomp( $cgitmp = `mktemp /tmp/cgi/XXXXXX`);
	die "Cannot create temp file: $cgitmp" unless (-f $cgitmp);
	open (TMPTXT,">$cgitmp") || die "Cannot open $cgitmp\n";
	print TMPTXT "$tmpstr\n";
	close TMPTXT || die "Cannot close $cgitmp\n";
	my @t = `/usr/local/bin/fm -r$length $cgitmp`;
	# the hash @t now contains the formatted text
	# if want it as a scalar rather than a list then
	# invoke capture the output as a scalar ...

However, you might be concerned about a possible security hole (using
the shell to read back a string). Still if you are using the latest copy
of perl and/or you have already checked $tmpstr for shell meta
characters, I don't think this would be an issue. And if you feel
strongly enough about it, you could modify the fm script to write to a
another temp file (rather than stdout) and return the name of the file

Although this means modifying the code ... and if you start doing that
you might want to turn it into a module.

Hope this is helpful ...

Cheers,

Gerry Patterson


Hi Gerry,

Thanks for your reply. I forgot to mention that the OS is Windows. Sorry
about that. What I'd like to do is to pass a string to fm.pl and have it
return the parsed string or an array.  I don't know how difficult this is to
do.

Brian


Brian,

You can still do it. But it is more difficult. As far as I know the
general method outlined below will work in Windows 2000 or NT. I can't
guarantee that it will work with Windows 95/98 (which are very poor
operating systems in my experience).

But if you do have windows 2000 or NT, you need to overcome the
following difficulties:

First of all you do not have a system mktemp function. Fortunately there
is one available in the perl library. You will have to read about it in
your documentation. An example of this is as follows:

	use File::Temp qw/ tempfile tempdir /;
	($fh,$filename) = tempfile( $template, DIR => $dir );

NOTE: As with the unix function, the Xs in $template are replaced by
      random digits. This method opens the file and returns a file
      handle, so you don't need to open it. Also, according to the
      documention, Windows will automatically delete the file when it is
      closed, IF tempfile() is invoked in SCALAR mode. -- READ the
      documentation!

Also it may be difficult to persuade Windows to just execute perl
programs. You may need to add .PL to your PATHEXT environment variable.
This needs to be done at the system level. You may also want to use the
ftype and assoc commands to assign your processor. e.g. Sometimes this
has to be done at the command line as well as the GUI, as follows:

FTYPE Perl=C:\Perl\bin\Perl.exe "%1" %*
ASSOC .pl=Perl

This should be done by the user who owns the sessions that will be
running the programs.

Regards,

Gerry Patterson

Activate text links with w3m.

Here is a hint that might be useful to new users of w3m (like me). I discovered a useful feature in w3m recently. If I press ':' while viewing a (plain ASCII) text file, any text element that looks like a link is turned into one. You can then navigate to these links and activate them as you would in a HTML file. It is in the documentation, of course. So I could have discovered this little feature by RTFM. But who has time to RTFM?