Regular expressions can have a /x qualifier. It allows embedded comments and for the regular expression to be formatted for easy reading. To get a literal space you have to either

• backsladh escape it: "\ ", or
• put it in a chacter class: "[ ]"

• m/ one \  two/x
• m/ one [ ] two /x

I used /x to make it easier for you to see the alternations. You can remove it along with the comment (# to end of line), white space not in a character class and then change "[ ]" to " ".

I am now a little confused about what you are matching. You say you are given the string to match as an argument but you have two different strings "total rows rejected: number" and "number rows rejected". If you do put the argument into a regular expression then you are correct to use \Q \E.

thanks for the responses...

lemme make it clear ... the argument(s) which are given is jus the phrase. for example
total rejected rows

or
rejected number of rows

in the log file which im gonna parse it with the script contains:

log.txt


total rejected rows: 1000
total rejected rows:    1254
total rejected rows: 1000
total rejected rows:    1254
total rejected rows: 1000
3000 rejected number of rows
8700 rejected number of rows
65000 rejected number of rows
1200 rejected number of rows
4300 rejected number of rows
total rejected rows:    1254
total rejected rows: 1000
total rejected rows:    1254
total rejected rows: 1000
total rejected rows:    1254
54000 rejected number of rows
4000 rejected number of rows
[download]



the programs works only for "total rejected rows:", ie., if the number (desired result) is at the end of the search phrase, but if it is at the beginning for example, "rejected number of rows" the number present at the beginning is not returned... but always the search phrase has the digits either at the beginning or at the end... if u have more questions plz lemme kno...

thanks.

1. How is the search string given?
2. What search string is given?
3. How the input data vary?
4. How will what you search for depend on the input data?
5. Will you always be capturing the same data?

For the example you have given where you always want to capture a number after or before "rows rejected"

qr{(?|
    \Q$string\E [^\d]* (\d+)
|
    (\d+) [^\d]* \Q$string\E
)
}x
[download]

will capture the last number before a given search string or if there isn't one the first number after the string. Note given

records processed 23456, total rows rejected 567
[download]

it will match 23456.

What is the input when one row is rejected? Is it

1 rows rejected
[download]

or

1 row rejected
[download]

Know your data;)