Bash regex not capturing

Bash regex not capturing

References

Reference NO 1

http://stackoverflow.com/questions/15191346/bash-regex-not-capturing

Reference NO 2

http://stackoverflow.com/questions/3898461/how-to-capture-results-of-regex-and-replace-patterns-in-bash

Reference NO 3

http://www.linuxforums.org/forum/programming-scripting/173999-not-matching-bash-regex.html

Reference NO 4

http://www.linuxjournal.com/content/bash-regular-expressions

Reference NO 5

http://www.makkintosshu.com/journal/regular-expressions-in-bash-and-alternatives

Reference NO 6

http://mywiki.wooledge.org/BashGuide/Patterns

Reference NO 7

http://www.regular-expressions.info/refadv.html

Reference NO 8

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