Regular Expression Help

[Jim Doughty]

When reading lines of html text from a file, I'm trying to match the
following, I'm trying to match on a string of 6 numbers, delimited by
hyphens. e.g. 2-19-23-27-29-40

The following code fails to match, and so do may different variants.

if($inline !~ /((\d?\-){5}(\d?))/ ){
exit(-1);
}

The actual value of $inline is as follows:
<TD><B><FONTSIZ E="1"><FONTFACE ="Verdana,Helve tica,sans-serif">2-19-23-27-29-40</B></TD>


Any help would be appreciated.

[Gunnar Hjalmarsson]

Re: Regular Expression Help

Jim Doughty wrote:[color=blue]
> When reading lines of html text from a file, I'm trying to match
> the following, I'm trying to match on a string of 6 numbers,
> delimited by hyphens. e.g. 2-19-23-27-29-40
>
> The following code fails to match, and so do may different
> variants.
>
> if($inline !~ /((\d?\-){5}(\d?))/ ){
> exit(-1);
> }[/color]

\d? means 0 or 1 digit, while the string includes groups of more than
one digit. And why all those parentheses? Try this:

if ( $inline !~ /(?:\d+-){5}\d+/ ) {

Btw, you said that you are reading *lines* of text. In that case, the
script will exit unless every line matches. Is that what you want?

--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl

[Jim Doughty]

Re: Regular Expression Help

Gunnar:

I now understand why mine failed to match. Many Thanks. I use that
string to validate the format of the data, only agains one line. I want
ot exit becase if the data is bad there is no point in continuing.

BTW, what does ?: mean at the beginning of the regex you provided.

Again, Many Thanks!

Jim



Gunnar Hjalmarsson wrote:[color=blue]
> Jim Doughty wrote:
>[color=green]
>> When reading lines of html text from a file, I'm trying to match
>> the following, I'm trying to match on a string of 6 numbers,
>> delimited by hyphens. e.g. 2-19-23-27-29-40
>>
>> The following code fails to match, and so do may different
>> variants.
>>
>> if($inline !~ /((\d?\-){5}(\d?))/ ){
>> exit(-1);
>> }[/color]
>
>
> \d? means 0 or 1 digit, while the string includes groups of more than
> one digit. And why all those parentheses? Try this:
>
> if ( $inline !~ /(?:\d+-){5}\d+/ ) {
>
> Btw, you said that you are reading *lines* of text. In that case, the
> script will exit unless every line matches. Is that what you want?
>[/color]

[Gunnar Hjalmarsson]

Re: Regular Expression Help

[ Please put your response *after* the quoted part that you include in
your reply. ]

Jim Doughty wrote:[color=blue]
> I now understand why mine failed to match. Many Thanks.[/color]

You are welcome.
[color=blue]
> BTW, what does ?: mean at the beginning of the regex you provided.[/color]

Finding that out is a good reason to acquaint yourself with the
documentation of regular expressions in Perl. ;-)

http://www.perldoc.com/perl5.8.0/pod/perlre.html

--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl