front: Extract the First/Last N Elements of a Path

In trinker/pathr: Easy Manipulation and Piping of File Paths

Description

front - Extract the first n elements of a path. Similar to head (uses head under the hood). Compare the defualt settings to basename and dirname.

back - Extract the first n elements of a path. Similar to tail (uses tail under the hood).

Usage

front(x, n = -1, collapse = TRUE, ...)

back(x, n = 1, collapse = TRUE, ...)

Arguments

x	A parse_path object.
n	A single integer. If positive, size for the resulting object: number of elements for a vector. If negative, all but the n last/first number of elements of x.
collapse	logical. If TRUE the path elements will be collapsed with the "/" separator.
...	ignored.

Value

Returns a vector (either atomic or list of character path elements) of sub-paths.

See Also

basename, dirname

Other sub-path manipulation functions: before, index, swap

Examples

front(list(1:8), 3)
front(list(1:8), -3)

back(list(1:8), 3)
back(list(1:8), -3)

library(magrittr)
files %>%
    parse_path() %>%
    front()

files %>%
    parse_path() %>%
    front(3)

files %>%
    parse_path() %>%
    back()

files %>%
    parse_path() %>%
    back(3)

## Compare to basename/dirname
(fls <- file.path("","p1","p2","p3", c("file.pdf", "file.txt", "file.Rmd")))

basename(fls)
fls %>%
    parse_path() %>%
    back()

dirname(fls)
fls %>%
    parse_path() %>%
    front()

trinker/pathr documentation built on May 31, 2019, 9:41 p.m.