$ perldoc perlfunc | egrep '^ {7}[a-z]+ STR'
       index STR,SUBSTR,POSITION
       index STR,SUBSTR
       rindex STR,SUBSTR,POSITION
       rindex STR,SUBSTR

##</code><code>##

 $ perldoc perlfunc | egrep '^ {7}sort '
       sort SUBNAME LIST
       sort BLOCK LIST
       sort LIST

##</code><code>##

       sort BLOCK LIST
       sort SUBNAME LIST
       sort $SCALAR LIST
       sort \&SUBNAME LIST
       sort LIST

##</code><code>##

   sort SUBNAME LIST
   sort BLOCK LIST
   sort LIST
       In list context, this sorts the LIST and returns the
       sorted list value.  In scalar context, the behaviour
       of "sort()" is undefined.

       If SUBNAME and BLOCK are omitted, "sort"s in standard
       string comparison order.  Otherwise, SUBNAME or BLOCK
       provides a subroutine that returns an integer less
       than, equal to, or greater than 0, depending on how
       the elements of the list are to be ordered.  (The
       "<=>" and "cmp" operators are extremely useful in
       such routines.)

       SUBNAME should be the bareword name of a subroutine
       or a simple scalar variable (unsubscripted) containing
       either a subroutine name or a reference to a subroutine.
       BLOCK is just an anonymous, in-line subroutine.

           @names =   sort @names;
           @numbers = sort { $a <=> $b } @numbers;

           sub hi2lo { $b <=> $a }
           @numbers = sort hi2lo @numbers;

           my $comparison = \&hi2lo;
           @numbers = sort $comparison @numbers;

           # Syntax error:
           my %comparisons = get_compare_functions();
           @numbers = sort $comparisons{hi2lo} @numbers;
           #              Not allowed  ^^^^^^^

       Beware when trying to sort the list returned from a
       function call, as the obvious syntax does not do that:

           @sorted = sort foo($x,$y);   # same as:
           @sorted = sort foo $x,$y;    # or as:
           my @list = ($x,$y);
           @sorted = sort foo @list;
           # Put just $x and $y into @sorted,
           # using foo() to compare the values.

       You must instead use something like:

           @sorted = sort( foo($x,$y) );
           @sorted = sort { $a cmp $b } foo $x,$y;
           @sorted = sort +foo($x,$y);
           @sorted = sort &foo($x,$y);

       ...describe more esoteric details...

       ...don't include more examples until later...
       (so the examples of just syntax stand out)