apropos {utils}

R Documentation

Find Objects by (Partial) Name

Description

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

find() is a different user interface to the same task.

Usage

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

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

Arguments

what	character string with name of an object, or more generally a regular expression to match 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. Note that in R versions prior to 2.5.0, the default was implicitly ignore.case = FALSE.
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 whole word.

Details

If mode != "any" only those objects which are of mode mode are considered. If where is TRUE, the positions in the search list are returned as the names attribute.

find is a different user interface for the same task as apropos. However, by default (simple.words == TRUE), only full words are searched with grep(fixed = TRUE).

Note that in R versions prior to 2.5.0, what was allowed to be non-character, such that find(cor) worked as it does in S. This possibility has been dropped in line with the aim of minimizing all use of non-standard evaluation in R.

Value

For apropos character vector, sorted by name, possibly with 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 giving the names of the corresponding environments.

Author(s)

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

require(stats)


## Not run: apropos("lm")
apropos("GLM")                      # more than a dozen
## that may include internal objects starting '.__C__' if
## methods is attached
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("\\[")

## Not run: # everything 
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,}$")
table(nchar(apropos("^.{8,}$")))

## End(Not run)

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