Carriage return metacharacter "r" in Regular Expression
How is metacharacter "r" used in regular expression?
Explanation
In regex, "r" metacharacter is used to match carriage return in a string.
PHP Example:
<?php
$str = "hiox
india";
if (preg_match("/r/", $str, $matches))
echo "Pattern matches!";
else
echo "Pattern not matched!";
?>
Result :
Pattern matches!
In the above regex example the string "$str" has a carriage return, to the next line, so it is matched.
Perl Example:
#! C:programfilesperlbinperl
print "content-type: text/htmlnn";
$str = "hi how are you";
if ($str =~ m/r/)
{print "It's matched!";}
else
{print "It's not matched!";}
Result :
It's not matched!
In the above "r" metacharacter example for regex, there are no "carriage return" in the string, so its unmatched.