On 25/05/2012 21:51, Christopher Gray wrote:
Good day,
I have a text file containing records. While I can extract single
sub-strings, I cannot extract multiple sub-strings.
The records are of multiple types - only about a third of which have the
data I need.
An example of a "good" record is
Abc1234 STATUS open DESCRIPTION "A basket of melons" :: { fruittype 1}
I'm trying to extract the first (Abc1234), second (open), third (A basket of
melons) and fourth (1) strings.
I can extract each of them separately - but not together.
So - for example:
while (<FILE>) {
chomp;
next if !/\{\s+fruittype\s+(\d+)\s+}/;
my $Temp =$1;
}
Extracts the fruittype. However, when I try and have multiple extracts:
...
next if !/\STATUS\s+(\w+)\s+\{\s+fruittype\s+(\d+)\s+}/;
...
It fails.
What have I done wrong?
Hi Chris
Lets look at your regex
/\STATUS\s+(\w+)\s+\{\s+fruittype\s+(\d+)\s+}/
First of all you start with a \S, which will actually match any
non-space character, not the S that you intended. But that wouldn't
break your regex.
The regex as a whole is looking for
'STATUS'
some whitespace
some 'word' characters (0..9, A..Z, a..z and _)
some whitespace
an open brace '{'
some whitespace
'fruittype'
some whitespace
some digits (0..9)
some whitespace
a closing brace (which should reall be escaped but Perl forgives you)
This will match a string like
'---XTATUS www { fruittype 999 }'
But since "STATUS open " is followed by "DESCRIPTION" in your record
instead of an opening brace the match fails.
To match multiple fields, you can write a regex that matches the entire
string with parentheses around the parts that must be captured. This
will do what you want
while (<DATA>) {
my @data =
/(\w+)\s+STATUS\s+(\w+)\s+DESCRIPTION\s+"([^"]+)"\s+::\s+\{\s*fruittype\s+(\d+)\s*\}/;
print "$_\n" for @data;
}
**output**
Abc1234
open
A basket of melons
1
but you may need to adjust the regex if the quoted string can be
unquoted if is doesn't contain spaces.
HTH,
Rob
--
To unsubscribe, e-mail: beginners-unsubscr...@perl.org
For additional commands, e-mail: beginners-h...@perl.org
http://learn.perl.org/
