perl number of lines in a string

Question

Using perl, is there any single command which give me the number of lines inside a string?

my $linenum= .... $str ....

It should work for when the string is empty, single line, and multiple lines.

Answer 1

You can count number of newline chars \n in the string (or \r for Mac newline)

my $linenum = $str =~ tr/\n//;