utils (version 3.4.1)

apropos: 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.

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.

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).

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

require(stats)

<!-- %% some of these have enormous output that varies a lot by version -->
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)

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,}$")
table(nchar(apropos("^.{8,}$")))