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regexbisonflex-lexer

Regex to match dot character occuring alone in a line

A sentence containing a single dot marks the end of the required portion of a file. It may or may not be the EOF. If I use flex and bison to parse this file, how can I match this line using some regular expression? Or is there some other way? I cannot use "." in Flex grammar as it can come anywhere in any portion, may be as a part of some word, mail id, etc.

Example: if my input file is as shown:

This is a simple file for testing. mail_id: abc@fgl.mn date: 20.09.2011 here goes some lines of information.

.

[Here there can be more sentences].

I need to parse only till that line containing that ".". How can I do that?

Solution

  • The regular expression:

    ^\.$

    will match a line containing just a dot. ^ matches the beginning of a line, $ matches the end of a line.