1 03/31/83  substr
 2 
 3 Syntax:  substr STR I {N}
 4 
 5 
 6 Syntax as active function:  [substr STR I {N}]
 7 
 8 
 9 Function:  returns the portion of STR starting with the character in
10 position I and continuing for N characters (where I and N are decimal
11 integers; I must be greater than zero and N must be greater than or
12 equal to zero).  If N is omitted, the remainder of STR is returned.  If
13 I is greater than the length of STR, the null string is returned.  If N
14 is greater than the remainder of STR, the remainder is returned.