lindex

lindex( 
l_list 
g_element 
[ ?all g_all ]
) 
=> x_result / l_result / nil

Returns the index number of the given element in l_list.

l_list	A list of elements.
g_element	The element to be searched in l_list.
`?all` g_all	Specifies whether to print the index number for all occurrences of g_element.

x_result	The index number of g_element in l_list when `?all` is either `nil` or not specified.
l_result	The list of index numbers for all occurrences of g_element in l_list when `?all` is set to `t`.
`nil`	When the given element is not found in l_list.

lindex('(1 2 3 4) 2)

=> 2

lindex('(1 4 6 7 4 8 4) 4 ?all t)
=>(2 5 7)

lindex('(1 4 6 7 4 8 4) 4 ?all nil)
=>2