String function to Find how many times str2 is in str1?

Good morning,

Is there a string function in PSQL to count how many times one str is in
another string?

For example,
Str1 = "test test caa dtest testing EndofString";
Str2 = " ";

select funcName(Str1, Str2);

return 5

Because Str1 has 5 Str2.

Thanks !
Ly