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installed.packages: Find Installed Packages

installed.packages

R Documentation

Find Installed Packages

Description

Find (or retrieve) details of all packages installed in the specified libraries.

Usage

installed.packages(lib.loc = NULL, priority = NULL,
                   noCache = FALSE, fields = NULL,
                   subarch = .Platform$r_arch, ...)

Arguments

`lib.loc`	character vector describing the location of R library trees to search through, or `NULL` for all known trees (see `.libPaths`).
`priority`	character vector or `NULL` (default). If non-null, used to select packages; `"high"` is equivalent to `c("base", "recommended")`. To select all packages without an assigned priority use `priority = "NA"`.
`noCache`	Do not use cached information, nor cache it.
`fields`	a character vector giving the fields to extract from each package's `DESCRIPTION` file in addition to the default ones, or `NULL` (default). Unavailable fields result in `NA` values.
`subarch`	character string or `NULL`. If non-null and non-empty, used to select packages which are installed for that sub-architecture.
`...`	allows unused arguments to be passed down from other functions.

Details

installed.packages scans the ‘DESCRIPTION’ files of each package found along lib.loc and returns a matrix of package names, library paths and version numbers.

The information found is cached (by library) for the R session and specified fields argument, and updated only if the top-level library directory has been altered, for example by installing or removing a package. If the cached information becomes confused, it can be avoided by specifying noCache = TRUE.

Value

A matrix with one row per package, row names the package names and column names (currently) "Package", "LibPath", "Version", "Priority", "Depends", "Imports", "LinkingTo", "Suggests", "Enhances", "OS_type", "License" and "Built" (the R version the package was built under). Additional columns can be specified using the fields argument.

Note

This needs to read several files per installed package, which will be slow on Windows and on some network-mounted file systems.

It will be slow when thousands of packages are installed, so do not use it to find out if a named package is installed (use find.package or system.file) nor to find out if a package is usable (call requireNamespace or require and check the return value) nor to find details of a small number of packages (use packageDescription).

Examples

## confine search to .Library for speed
str(ip <- installed.packages(.Library, priority = "high"))
ip[, c(1,3:5)]
plic <- installed.packages(.Library, priority = "high", fields = "License")
## what licenses are there:
table( plic[, "License"] )