readBin
Read and Write Binary Data
Description
Read or write binary data from a connection.
Usage
readBin(con, what, n = 1L, size = NA_integer_, signed = TRUE,
endian = .Platform$endian)
writeBin(object, con, size = NA_integer_,
endian = .Platform$endian, useBytes = FALSE)
Arguments
| con |
a connection object or a character string naming a file.
|
| object |
an atomic object to be written to con.
|
| what |
a character string denoting the mode of the data to be read. Can be
one of '"numeric", "double", "integer", "int",
"logical", "complex", or "character".
Alternatively, what can be an object whose
mode is used for the mode of the object to read.
|
| n |
an integer specifying the maximum number of values to read.
|
| size |
an integer specifying the number of bytes per value read.
The default of NA_integer_ uses a default size for a value of the
given mode (4 for integer and single, 8 for double, and 16 for complex:
the same for both 32- and 64-bit versions of Spotfire Enterprise Runtime for R).
This argument is ignored for character data. Rather, character data is read as null-terminated
strings of single byte characters.
|
| signed |
a logical value. Used only for integers of sizes 1 and 2. If TRUE (the default), integers
are regarded as signed integers.
|
| endian |
a character string. If endian="big" or endian="little", specifies
the endian-ness of the values read or written. If endian="swap"
the endian-ness is swapped. Intel hardware is "little" endian and
Sun hardware is "big" endian.
|
| useBytes |
a logical value. Ignored by Spotfire Enterprise Runtime for R.
In R, if FALSE (the default), specifies that writeBin should
convert strings with encodings to a printable string before writing the bytes.
If TRUE, specifies that writeBin should write the unconverted string bytes.
|
Details
If con is a character string, the function creates a file
connection to a file of that name.
Value
| readBin | returns a vector of the appropriate mode.
The length is the number of items read. |
| writeBin | returns NULL or a raw vector (if con is a raw vector). |
Differences between Spotfire Enterprise Runtime for R and Open-source R
- In open-source R, the useBytes argument to writeBin specifies
whether to write encoded strings in a form that can be printed. For
example, if R cannot display Unicode characters, writeBin("\u30A4",f,useBytes=FALSE) would write the bytes for
the string "a<U+30A4>;b", whereas
writeBin("\u30A4",f,useBytes=TRUE) would write the bytes
contained in the string as produced by charToRaw.
- Spotfire Enterprise Runtime for R ignores the useBytes argument, and always writes the
string bytes as produced by charToRaw.
See Also
Examples
tf <- tempfile()
x <- as.integer(c(-1,1)*3^(0:19))
writeBin(con=tf, x)
readBin(tf, integer(), n=20)
unlink(tf)