package_dependencies {tools} | R Documentation

## Computations on the Dependency Hierarchy of Packages

### Description

Find (recursively) dependencies or reverse dependencies of packages.

### Usage

    package_dependencies(packages = NULL, db = NULL,
            which = c("Depends", "Imports", "LinkingTo"),
    	recursive = FALSE, reverse = FALSE, verbose = getOption("verbose"))

### Arguments

`packages` | a character vector of package names.
`db` | character matrix as from `available.packages()` (with the default `NULL` the results of this call) or data frame variants thereof. Alternatively, a package database like the one available from https://cran.r-project.org/web/packages/packages.rds.
`which` | a character vector listing the types of dependencies, a subset of `c("Depends", "Imports", "LinkingTo", "Suggests", "Enhances")`. Character string `"all"` is shorthand for that vector, character string `"most"` for the same vector without `"Enhances"`.
`recursive` | logical: should (reverse) dependencies of (reverse) dependencies (and so on) be included?
`reverse` | logical: if `FALSE` (default), regular dependencies are calculated, otherwise reverse dependencies.
`verbose` | logical indicating if output should monitor the package search cycles.

### Value

Named list with one element for each package in argument `packages`, each consists of a character vector naming the (recursive) (reverse) dependencies of that package.

For given packages which are not found in the db, `NULL` entries are returned, as opposed to `character(0)` entries which indicate no dependencies.

### See Also

`dependsOnPkgs`, and `package.dependencies` for checking dependencies.

### Examples

    myPkgs <- c("MASS", "Matrix", "KernSmooth", "class", "cluster", "codetools")
    pdb <- available.packages()
    system.time(
    dep1 <- package_dependencies(myPkgs, db = pdb) # all arguments at default
    ) # very fast
    utils::str(dep1, vec.len=10)

    system.time( ## reverse dependencies, recursively --- takes much longer:
    deps <- package_dependencies(myPkgs, db = pdb,
                        which = c("Depends", "Imports", "LinkingTo", "Suggests"),
                        recursive = TRUE, reverse = TRUE)
    ) # seen ~ 10 seconds

    lengths(deps) # 2015-01-14: all are 7040, but codetools with 7046

[Package tools version 3.6.1 Index]