ls                   package:base                   R Documentation

List Objects

Description:

     `ls' and `objects' return a vector of character strings giving the
     names of the objects in the specified environment. When invoked
     with no argument at the top level prompt, `ls' shows what data
     sets and functions a user has defined. When invoked with no
     argument inside a function, `ls' returns the names of the
     functions local variables. This is useful in conjunction with
     `browser'.

Usage:

     ls(name, pos = -1, envir = as.environment(pos),
        all.names = FALSE, pattern)
     objects(name, pos= -1, envir = as.environment(pos),
             all.names = FALSE, pattern)

Arguments:

    name: which environment to use in listing the available objects.
          Defaults to the current environment.  Although called `name'
          for back compatibility, in fact this argument can specify the
          environment in any form; see the details section.

     pos: An alternative  argument to `name' for specifying the
          environment as a position in the search list.  Mostly there
          for back compatibility.

   envir: an alternative  argument to `name' for specifying the
          environment evaluation environment. Mostly there for back
          compatibility.

all.names: a logical value.  If `TRUE', all object names are returned. 
          If `FALSE', names which begin with a ``.'' are omitted.

 pattern: an optional regular expression, see `grep'. Only names
          matching `pattern' are returned.

Details:

     The `name' argument can specify the  environment from which object
     names are taken in one of several forms: as an integer (the
     position in the `search' list); as the character string name of an
     element in the search list; or as an explicit `environment'
     (including using `sys.frame' to access the currently active
     function calls). By default, the environment of the call to `ls'
     or `objects' is used. The `pos' and `envir' arguments are an
     alternative way to specify an environment, but are primarily there
     for back compatibility.

See Also:

     `apropos' (or `find') for finding objects in the whole search
     path; `grep' for more details on ``regular expressions''; `class',
     `methods', etc. for object-oriented programming.

Examples:

     .Ob <- 1
     ls(pat="O")
     ls(pat="O", all = TRUE)    # also shows ".[foo]"

     # shows an empty list because inside myfunc no variables are defined
     myfunc <- function() {ls()}
     myfunc()

     # define a local variable inside myfunc
     myfunc <- function() {y <- 1; ls()}
     myfunc()                # shows "y"

