test if a string contains a substring

1)
set exist_substring = `echo $string | grep -c $substring`
if ( $exist_substring == 1 ) then
      echo "$substring exists in the $string"
endif

2) ---to test if str exists in $mystring:
echo $mystring | awk '{print index($0, "str")}'" searches the $mystring variable for an occurrence of "str" in the string's value.

if exists, return 1, otherwise 0