apropos {utils}

R Documentation

Find Objects by (Partial) Name

Description

apropos() returns a character vector giving the names of objects in the search list matching (as a regular expression) what.

find() returns where objects of a given name can be found.

Usage

apropos(what, where = FALSE, ignore.case = TRUE, mode = "any")

find(what, mode = "any", numeric = FALSE, simple.words = TRUE)

Arguments

what	character string. For simple.words = FALSE the name of an object; otherwise a regular expression to match object names against.
where, numeric	a logical indicating whether positions in the search list should also be returned
ignore.case	logical indicating if the search should be case-insensitive, TRUE by default.
mode	character; if not "any", only objects whose mode equals mode are searched.
simple.words	logical; if TRUE, the what argument is only searched as a whole word.

Details

If mode != "any" only those objects which are of mode mode are considered.

find is a different user interface for a similar task to apropos. By default (simple.words == TRUE), only whole names are matched. Unlike apropos, matching is always case-sensitive.

Unlike the default behaviour of ls, names which begin with a ‘⁠.⁠’ are included (and these are often ‘internal’ objects — as from R 3.4.0 most such are excluded).

Value

For apropos, a character vector sorted by name. For where = TRUE this has names giving the (numerical) positions on the search path.

For find, either a character vector of environment names or (for numeric = TRUE) a numerical vector of positions on the search path with names the names of the corresponding environments.

Author(s)

Originally, Kurt Hornik and Martin Maechler (May 1997).

See Also

glob2rx to convert wildcard patterns to regular expressions.

objects for listing objects from one place, help.search for searching the help system, search for the search path.

Examples

Run examples

require(stats)


## Not run: apropos("lm")
apropos("GLM")                      # several
apropos("GLM", ignore.case = FALSE) # not one
apropos("lq")

cor <- 1:pi
find("cor")                         #> ".GlobalEnv"   "package:stats"
find("cor", numeric = TRUE)                     # numbers with these names
find("cor", numeric = TRUE, mode = "function")  # only the second one
rm(cor)

## Not run: apropos(".", mode="list")  # a long list

# need a DOUBLE backslash '\\' (in case you don't see it anymore)
apropos("\\[")

# everything % not diff-able
length(apropos("."))

# those starting with 'pr'
apropos("^pr")

# the 1-letter things
apropos("^.$")
# the 1-2-letter things
apropos("^..?$")
# the 2-to-4 letter things
apropos("^.{2,4}$")

# the 8-and-more letter things
apropos("^.{8,}$")
table(nchar(apropos("^.{8,}$")))

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