Searching functions using grep over multiple loaded packages in R

Question

Lets say I have package base, dplyr, data.table, tidyr etc. loaded using sapply().

 sapply(c         


        

Answer 1

To get a list of all packages which are loaded, use:

x <- grep('package:',search(),value=TRUE)  # Comment below by danielson
# e.g. ("package:base", "package:data.table")

sapply(x, function(x) {
    paste0(x, ":", grep("is\\.", ls(x),value=TRUE))
})

Output:

$`package:base`
 [1] "package:base:is.array"              "package:base:is.atomic"
 [3] "package:base:is.call"               "package:base:is.character"
 [5] "package:base:is.complex"            "package:base:is.data.frame"
 [7] "package:base:is.double"             "package:base:is.element"
 ...

$`package:data.table`
[1] "package:data.table:is.data.table"

Answer 2

Thanks to all. So here are Answers in 3 Versions to the question I posted with all the help here

Note: The priority was to search for a pattern over multiple loaded packages, you can search some other pattern instead of "is."

VERSION 1

 ## Get list of loaded packages into X 

 X <- grep('package:',search(),value=TRUE)  # Comment by danielson

 # Use grep to find functions with is. pattern over multiple loaded packages inside X

 sapply(X, function(X) {
 paste0(X, ":", grep("is\\.", ls(X),value=TRUE))
 })

VERSION 2

 ## Get list of loaded packages into X 

 X <- .packages()    # Comment by docendo discimus

 # Use grep to find functions with is. pattern over multiple loaded packages inside X

 sapply(X, function(X) {
 paste0(X, ":", grep("is\\.", ls(paste0("package:",X)),value=TRUE))
 })

VERSION 3 - Without grep() function

 ## Get list of loaded packages into X 

 X <- .packages()

 # find functions using `ls()` with is. pattern over multiple loaded packages inside X
 # Suggested by Rich Scriven Over Comments

 sapply(X, function(X) { 
 paste0(X,":",ls(paste0("package:",X), pattern = "is\\."))
 })