How to List all Functions of an R-Package

ls("package:base")
   [1] "-"                                  "-.Date"                            
   [3] "-.POSIXt"                           "!"                                 
   [5] "!.hexmode"                          "!.octmode"                         
   [7] "!="                                 "$"                                 
   [9] "$.DLLInfo"                          "$.package_version"                 
  [11] "$<-"                                "$<-.data.frame"                    
  [13] "%%"                                 "%*%"                               
  [15] "%/%"                                "%in%"                              
  [17] "%o%"                                "%x%"                               
  [19] "&"                                  "&&"                                
  [21] "&.hexmode"                          "&.octmode"                         
  [23] "("                                  "*"    
...

lsf.str("package:base")
- : function (e1, e2)  
-.Date : function (e1, e2)  
-.POSIXt : function (e1, e2)  
! : function (x)  
!.hexmode : function (a)  
!.octmode : function (a)  
!= : function (e1, e2)  
$ : .Primitive("$") 
...