Package 'base64enc'

Encode/decode data into/from base64 encoding

Description

base64encode encodes a data into base64 encoding. The source can be a file, binary connection or a raw vector.

base64decode decodes a base64-encoded string into binary data. The source can be a string or a connection, the output is either a raw vector (output=NULL) or a binary connection.

Usage

base64encode(what, linewidth, newline)
base64decode(what, output = NULL, file)

Arguments

what	data to be encoded/decoded. For base64encode it can be a raw vector, text connection or file name. For base64decode it can be a string, raw vector or a binary connection.
linewidth	if set, the output is split into lines with at most linewidth characters per line. Zero or NA denotes no limit and values 1 .. 3 are silently treated as 4 since that is the shortest valid line.
newline	only applicable if linewidth is set; if set (string), the result will be a single string with all lines joined using the newline string
output	if NULL then the output will be a raw vector with the decoded data, otherwise it must be either a filename (string) or a binary connection.
file	file name (string) for data to use as input instead of what. It is essentially just a shorthand for base64decode(file(name)). Only one of what and file can be specified.

Value

base64encode: A character vector. If linewith > 0 and newline is not set then it will consist of as many elements as there are lines. Otherwise it is a single string.

base64decode: If output = NULL then a raw vector with the decoded content, otherwise the number of bytes written into the connection.

Author(s)

Simon Urbanek

Examples

base64encode(1:100)
  base64encode(1:100, 70)
  base64encode(1:100, 70, "\n")
  x <- charToRaw("the decoded content, otherwise the number of bytes")
  y <- base64decode(base64encode(x))
  stopifnot(identical(x, y))

---

Check the validity of a byte stream ot be interpreted as UTF8.

Description

checkUTF8 check whether a given raw vector can be used as a valid string encoded in UTF8.

Usage

checkUTF8(what, quiet = FALSE,	charlen = FALSE, min.char = 1L)

Arguments

what	raw vector with the payload
quiet	logical, if TRUE then the function will not fail but report success/failure via its result, otherwise failures are considered errors.
charlen	logical, if TRUE then the function returns the length of the longest byte sequence representing a character in the file.
min.char	integer, any bytes below this value are considered control chacters and reported as errors. The default value of 1L guards against strings including NULs.

Value

If charlen=FALSE: TRUE on success, FALSE if the payload is invalid and quite=TRUE.

If charlen=TRUE: positive integer corresponding to the longest encoded sequence on success, negative integer on failure.

Author(s)

Simon Urbanek

---

Create a data URI string

Description

dataURI creates URI with the data: scheme by encoding the payload either using base64 ot URI encoding.

Usage

dataURI(data, mime = "", encoding = "base64", file)

Arguments

data	raw vector, connection or character vector to use as payload. Character vectors of more than one element are collapsed using "\n" before encoding.
mime	MIME-type of the data (per standard "" is interpreted as "text/plain;charset=US-ASCII" without including it in the URI)
encoding	data encoding to use. Must be either "base64" or NULL
file	filename (string) to open as payload. file and data are mutually exclusive

Value

string of the form data:[mime][;base64],<encoded-payload>

Author(s)

Simon Urbanek

References

RFC 2397 The "data" URL scheme

Examples

dataURI(as.raw(1:10)) # default is base64
  dataURI(as.raw(1:10), encoding=NULL) # URI
  if (require("png", quietly=TRUE)) {
    # let's say you have an image - e.g. from dev.capture(TRUE)
    img <- matrix(1:16/16, 4)
    dataURI(writePNG(img), "image/png")
    # or straight from a file
    dataURI(file=system.file("img", "Rlogo.png", package="png"), mime="image/png")
  }

---