Hi,
I have a requirement to filter multiple entries in a text file.
Entries are a pair of 2 lines .Like

line1
line2
.......
........
Here line1, line2 consist of one pair. line1 and line2 contain different data.
There can be multiple entries for the same pair. And there can be 'n' such pairs having multiple entries.
Is there a method available in perl/shell scripting to filter the multiple entries.
Could any one guide me to achieve this? Any help is appreciated.

Thanks in advance.
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Suman