14. Metacharacters: ^ and $

• So, let's look at some examples of using ^ and $.
• Consider the file example02.txt:

    This is another file with grey in it.
    It's all about the colour gray
    grey is all that seems to be in here
    but don't get all gray about it!
          

• Now, let's use grep again:

    grep '^gr[ea]y' example02.txt
          

• The result is:

    grey is all that seems to be in here
          

• Similarly, if we use the regex:

    grep 'gr[ea]y$' example02.txt
          

• The result is:

    It's all about the colour gray
          

• Simple, isn't it?

• Confession time: It's not actually as simple as all that. Matching the start and end of a line is all very well for when we grep the lines in a file, or when editing the lines of a file in vi, but what happens when we read in an entire file into a single variable in Perl? Where's the start and end of a line in that? Or is it now the start and end of the target string, which is suddenly a file? What if the file has embedded newlines in it?
• We'll come back to this after we've seen another metacharacter we need to know about first.