Infer the MIME type from a file name

This function returns the MIME type, i.e. part of the value used in the Content-Type for an HTTP request/response or in email to identify the nature of the content. This is a string such as "text/plain" or "text/xml" or "image/png".

The function consults an R object constructed by reading a Web site of known MIME types (not necessarily all) and matching the extension of the file name to the names of that table.

guessMIMEType(name, default = NA)

Arguments

name

character vector of file names

default

the value to use if no MIME type is found in the table for the given file name/extension.

Value

A character vector giving the MIME types for each element of name.

References

The table of MIME types and extensions was programmatically extracted from http://www.webmaster-toolkit.com/mime-types.shtml with tbls = readHTMLTable("http://www.webmaster-toolkit.com/mime-types.shtml") tmp = tbls[[1]][-1,] mimeTypeExtensions = structure(as.character(tmp[[2]]), names = gsub("^\.", "", tmp[[1]])) save(mimeTypeExtensions, file = "data/mimeTypeExtensions.rda") The IANA list is not as convenient to programmatically compile.

Author

Duncan Temple Lang

See also

Uploading file.

Examples

 guessMIMEType(c("foo.txt", "foo.png", "foo.jpeg", "foo.Z", "foo.R"))
#>                  foo.txt                  foo.png                 foo.jpeg 
#>             "text/plain"              "image/png"             "image/jpeg" 
#>                    foo.Z                    foo.R 
#> "application/x-compress"            "text/R-code" 

 guessMIMEType("foo.bob")
#> foo.bob 
#>      NA 
 guessMIMEType("foo.bob", "application/x-binary")
#>                foo.bob 
#> "application/x-binary"