Re^2: find one by one occurances

Hi Corion,
I have already given required input and output. See the below code what i am trying to do? I need to identify years in a line and it may come like 2005, 2005a, a2005, May 31, 2005 some thing like that. Here first i am trying to find the occurance.
I need the below output:
1. i need to find out the words which has 4 digits number. it's my first requirement.
2. then i should collect all years and needs to find before/after two words due to full date appearances.

$var='Hobbs, F. 2005a. Examining American Household Composition: b1990
+ and 2000. U.S. Census Bureau, Census 2000 Special Reports, CENSR-24.
+ I.S. Government Printing Office, Washington, DC.';

#$var=~s/(\w?) (\w?) ([0-9]{4}+[a-zA-Z]?) (\w?) (\w?)/&identify_year($
+1.$2.$3.$4.$5)/ge;

$var=~s/([0-9]{4})/&identify_year($1)/ge;

sub identify_year
{
  my ($input)=@_;

  print "$input\n";
  return ($input);
}
[download]

Comment on Re^2: find one by one occurances Download Code

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Re^3: find one by one occurances by Corion (Patriarch) on Jul 23, 2010 at 06:26 UTC
Why do you try `s/.../identify_year($1)/ge`? What is that supposed to do? I thought your objective was to identify a year and the surrounding words? If you want to know whether there is one or more occurrence of a regular expression, you can use the following idiom: `my $var = "This is the year 2000."; my @matches = ($var =~ /([0-9]{4})/g);` [download] The regular expression I gave will only find four digits. You will need to modify that regular expression to also recognize two words before that year and two words after that year.	[reply] [d/l] [select]
Re^4: find one by one occurances by Selvakumar (Scribe) on Jul 23, 2010 at 07:11 UTC
that's the question i was raised here. How to modify the regular expression to find consecutive 5 words which the center word has year. if i use some thing like below `#$var=~s/(\w?) (\w?) ([0-9]{4}+[a-zA-Z]?) (\w?) (\w?)/&identify_year($ +1.$2.$3.$4.$5)/ge;` [download] it's not giving my required output and it fails here. "b1990 and 2000." U.S. etc., if u try. read my all questions clearly the year can occurs in any format not only 4 digits.	[reply] [d/l]
Re^5: find one by one occurances by Corion (Patriarch) on Jul 23, 2010 at 07:26 UTC
That is what you have to do. See perlretut and/or perlre. This is not a code writing service where we will write code for you. Maybe you might be interested in that `/\w?/` will only match zero or one "word character". If you want to match one or more, you might want to use `\w+`. Again, now is a good time to learn about regular expressions.	[reply] [d/l] [select]