detach

R Base 3.6.2

Detach a database, i.e., remove it from the search() path of available R objects. Usually this is either a data.frame which has been attached or a package which was attached by library.

Syntax

detach(name, pos = 2L, unload = FALSE, character.only = FALSE,
       force = FALSE)

Arguments

Parameter	Description
`name`	The object to detach. Defaults to search()[pos]. This can be an unquoted name or a character string but not a character vector. If a number is supplied this is taken as pos.
`pos`	Index position in search() of the database to detach. When name is a number, pos = name is used.
`unload`	A logical value indicating whether or not to attempt to unload the namespace when a package is being detached. If the package has a namespace and unload is TRUE, then detach will attempt to unload the namespace via unloadNamespace: if the namespace is imported by another namespace or unload is FALSE, no unloading will occur.
`character.only`	a logical indicating whether name can be assumed to be a character string.
`force`	logical: should a package be detached even though other attached packages depend on it?

Return Value

The return value is invisible. It is NULL when a package is detached, otherwise the environment which was returned by attach when the object was attached (incorporating any changes since it was attached).

Details

This is most commonly used with a single number argument referring to a position on the search list, and can also be used with a unquoted or quoted name of an item on the search list such as package:tools. If a package has a namespace, detaching it does not by default unload the namespace (and may not even with unload = TRUE), and detaching will not in general unload any dynamically loaded compiled code (DLLs). Further, registered S3 methods from the namespace will not be removed. If you use library on a package whose namespace is loaded, it attaches the exports of the already loaded namespace. So detaching and re-attaching a package may not refresh some or all components of the package, and is inadvisable.

Examples

Example

# NOT RUN {
require(splines) # package
detach(package:splines)
## or also
library(splines)
pkg <- "package:splines"
# }
# NOT RUN {
detach(pkg, character.only = TRUE)

## careful: do not do this unless 'splines' is not already attached.
library(splines)
detach(2) # 'pos' used for 'name'

## an example of the name argument to attach
## and of detaching a database named by a character vector
attach_and_detach <- function(db, pos = 2)
{
   name <- deparse(substitute(db))
   attach(db, pos = pos, name = name)
   print(search()[pos])
   detach(name, character.only = TRUE)
}
attach_and_detach(women, pos = 3)
# }