ls
List Objects
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
function's local variables: this is useful in conjunction with
browser
.
- Keywords
- environment
Usage
ls(name, pos = -1L, envir = as.environment(pos), all.names = FALSE, pattern)
objects(name, pos= -1L, 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. Mostly there for back compatibility. - all.names
- a logical value. If
TRUE
, all object names are returned. IfFALSE
, names which begin with a . are omitted. - pattern
- an optional regular expression. Only names
matching
pattern
are returned.glob2rx
can be used to convert wildcard patterns to regular expressions.
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.
Note that the order of the resulting strings is locale
dependent, see Sys.getlocale
.
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
See Also
glob2rx
for converting wildcard patterns to regular
expressions.
ls.str
for a long listing based on str
.
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
library(base)
.Ob <- 1
ls(pattern = "O")
ls(pattern= "O", all.names = 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"