String Search

[Sishanth]

Hi, I have a hash that contains 1000's of words. I have a string eg $str = 'Hi this is the sample string for string search'

I need to search the string in the hash. And the match is not the entire string match, it is like hash may contain only 'Hi' or 'Hi this is' or 'sample string'. My perl should match all the combination of the given string with the hash. Any idea for this.

[BrowserUk]

Just iterate the combinations of words from the string:

#! perl -slw
use strict;

# my %hash = ...;
my $str = 'Hi this is the sample string for string search';
my @words = split ' ', $str;

for my $start ( 0 .. $#words - 1 ) {
    for my $end ( $start .. $#words ) {
        print "Lookup: ", join ' ', @words[ $start .. $end ];
    }
}

__END__
C:\test>1001794
Lookup: Hi
Lookup: Hi this
Lookup: Hi this is
Lookup: Hi this is the
Lookup: Hi this is the sample
Lookup: Hi this is the sample string
Lookup: Hi this is the sample string for
Lookup: Hi this is the sample string for string
Lookup: Hi this is the sample string for string search
Lookup: this
Lookup: this is
Lookup: this is the
Lookup: this is the sample
Lookup: this is the sample string
Lookup: this is the sample string for
Lookup: this is the sample string for string
Lookup: this is the sample string for string search
Lookup: is
Lookup: is the
Lookup: is the sample
Lookup: is the sample string
Lookup: is the sample string for
Lookup: is the sample string for string
Lookup: is the sample string for string search
Lookup: the
Lookup: the sample
Lookup: the sample string
Lookup: the sample string for
Lookup: the sample string for string
Lookup: the sample string for string search
Lookup: sample
Lookup: sample string
Lookup: sample string for
Lookup: sample string for string
Lookup: sample string for string search
Lookup: string
Lookup: string for
Lookup: string for string
Lookup: string for string search
Lookup: for
Lookup: for string
Lookup: for string search
Lookup: string
Lookup: string search

Where words (or word combinations) appear twice in the string, they will be looked up twice, but that will be faster than de-duplicating the combinations.

Whether that is a problem will depend on whether you consider the same word or phrase appearing in different places duplicates or not; and what you are doing with the information you are generating.

[space_monk]

The previous answer shows how to start to address the problem raised, but I get the impression that the question which has been asked is the wrong question.

Does the hash contain these 'thousands of words' as a key or a value? It would have been useful if the original question could have contained a small hash showing the data layout.

Perhaps the real question should explain why you have such a hash and why you're looking for string matches?

[BrowserUk]

By posting your (perfectly valid) point as a reply to me, rather than the OP, you have probably ensured that he will never see it.