guess_type function

Guess the MIME types from filenames

Look up in the mimemap table for the MIME types based on the extensions of the given filenames.

guess_type(
  file,
  unknown = "application/octet-stream",
  empty = "text/plain",
  mime_extra = mimeextra,
  subtype = ""
)

Arguments

• file: a character vector of filenames, or filename extensions

• unknown: the MIME type to return when the file extension was not found in the table

• empty: the MIME type for files that do not have extensions

• mime_extra: a named character vector of the form c(extension = type)

  providing extra MIME types (by default, mime:::mimeextra); note this MIME table takes precedence over the standard table mimemap

• subtype: a character vector of MIME subtypes, which should be of the same length as file if provided (use an empty character string for a file if we do not want a subtype for it)

Examples

library(mime)
# well-known file types
guess_type(c("a/b/c.html", "d.pdf", "e.odt", "foo.docx", "tex"))
# not in the standard table, but in mimeextra
guess_type(c("a.md", "b.R"), mime_extra = NULL)
guess_type(c("a.md", "b.R"))

# override the standard MIME table (tex is text/x-tex by default)
guess_type("tex", mime_extra = c(tex = "text/plain"))
# unknown extension 'zzz'
guess_type("foo.zzz")
# force unknown types to be plain text
guess_type("foo.zzz", unknown = "text/plain")

# empty file extension
guess_type("Makefile")
# we know it is a plain text file
guess_type("Makefile", empty = "text/plain")

# subtypes
guess_type(c("abc.html", "def.htm"), subtype = c("charset=UTF-8", ""))