suniln:

On the line where you say:

$key="C:\abc\dfg";

Your string $key doesn't actually have any backslashes ('\') in it. When in double-quotes, the backslash is a special character that combines with the next character to tell perl what to insert into the string. For example, "\t" indicates a tab character (a byte containing 09H), and "\n" tells perl to start a new line (a byte containing 0DH). So the string: "dog\n\tcat" tells perl to build a string holding "dog", a newline, a tab character, and "cat". There are no backslashes in the string.

You can correct this problem by putting the value in single quotes, e.g.,

$key='C:\abc\dfg';

or you can tell perl you really want a backslash (by using two backslashes!):

$key="C:\\abc\\dfg";

Alternatively, you can use the forward slash: In most cases, Windows/DOS is happy with forward slashes in file names. Perl and Unix are happy with it too, so that's what I do nearly everywhere:

$key="C:/abc/dfg";

So, the long and short of it is that you're not matching because you have no backslashes in your string, along with any other problems the expression might have.

...roboticus

FYI: Be sure to preview your post and update the formatting before pressing the "create" button! Also, you can go back and update a post to add code tags, rather than start a new one.

Update: Fixed byte value for tab from "08H" to "09H". Thanks to bart for the catch!

Update: Fixed order of tab and newline in example text. Thanks to johngg for noticing that one.