Testing a string for a substring

[John E]

I understand that if I have a string in perl called "my_str" and it happens to be "Tuesday" I can test it like this:-

if ($my_str eq Tuesday) {
#  do something here, because it's Tuesday !
}

But suppose I want to test for the substring "day" - so that "daytime", "Monday", "Tuesday", "Saturday" etc would all would all provide a positive match - how can I achieve that with perl


[Footnote...] I discovered a way to achieve this using the index statement - e.g.

if (-1 != index($my_str, "day")) {
#  do something
}

but I assume that'll probably be case sensitive. Case sensitivity isn't necessarily undesirable but I just wondered if there's any other function available that's more elegant / more suited to string searches?

[PeejAvery]

Rather than use index, you can just use a case insensitive regular expression match.

if ($string =~/findme/i) {
  ...
}