Fetch selected files out of a .zip in a Zenodo record without downloading it

A zip published on Zenodo is often mostly material a reader does not need: stimuli, images, or videos alongside the few data files. Zenodo serves its per-file URLs with byte-range support, and every member of a zip is compressed on its own, so individual members can be pulled out of the archive while the rest is never transferred (see .zip_member_fetch()). Verified 2026-08-13 on record 13384475: one 2.06 MB member out of a 129.8 MB archive in about half a second.

Usage

.zenodo_zip_members(
  url,
  dest,
  keep_types = c("data", "documentation"),
  max_file_size = 10,
  size = NULL
)

Arguments

url

the zip's self download URL in the record

dest

directory to write the extracted members into

keep_types

file categories worth extracting, as data_classify_files() names them; the default keeps data and documentation and skips materials, matching zip_decision()

max_file_size

largest member to extract (in MB), applied per member exactly as the record-level cap is applied per file

size

the zip's size in bytes as the record lists it, or NULL. Passed on to zip_peek() so it does not have to send a HEAD request to learn a size the record listing already gave.

Value

a data frame with one row per extracted member (name, path, size, ok), or NULL when the archive could not be listed and the caller should download it whole instead

Details

This is not possible for every archive. .7z, .rar and .tar.gz compress all their files as one stream, so nothing inside can be read without decompressing everything before it, and Zenodo's own whole-record files-archive endpoint ignores range requests entirely. Both cases fall back to downloading the archive whole.