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First candidate path that exists

Source: R/path_resolution.R
first_existing_path.Rd

Returns the first element of candidates for which dir.exists() is TRUE. If none exist but one has a parent directory that exists, creates that candidate and returns it. Errors if none of the candidates or their parents exist.

Usage

first_existing_path(candidates, label = NULL)

Arguments

candidates

Character vector of candidate paths, in priority order.

label

Optional label used in error messages to describe what kind of path is being resolved (e.g. "data_rawbatch_dir").

Value

A single character path: the first candidate that exists, or a newly-created one.

Details

This is the stateless primitive used by CandidatePath for resolution. Scripts that just need "give me the first of these paths that exists" can call it directly.

See also

CandidatePath for the stateful, caching wrapper used by the R6 classes in this package; invalidate_candidate_paths() for the save-time cache clearer that makes objects portable across hosts.

Other multi_host_paths: CandidatePath, invalidate_candidate_paths()

Examples

d <- tempfile()
dir.create(d)
first_existing_path(c("/definitely/not/there", d))
#> [1] "/tmp/RtmpKg4QzZ/file1d123eb16780"