| rawConnection {base} | R Documentation |
Input and output raw connections.
rawConnection(object, open = "r")
rawConnectionValue(con)
object |
character or raw vector. A description of the connection. For an input this is an R raw vector object, and for an output connection the name for the connection. |
open |
character. Any of the standard connection open modes. |
con |
an output raw connection. |
An input raw connection is opened and the raw vector is copied
at the time the connection object is created, and close
destroys the copy.
An output raw connection is opened and creates an R raw vector
internally. The raw vector can be retrieved via
rawConnectionValue.
If a connection is open for both input and output the initial raw vector supplied is copied when the connections is open
For rawConnection, a connection object of class
"rawConnection" which inherits from class "connection".
For rawConnectionValue, a raw vector.
As output raw connections keep the internal raw vector up to date
call-by-call, they are relatively expensive to use (although
over-allocation is used), and it may be better to use an anonymous
file() connection to collect output.
On (rare) platforms where vsnprintf does not return the needed length
of output there is a 100,000 character limit on the length of line for
output connections: longer lines will be truncated with a warning.
zz <- rawConnection(raw(0), "r+") # start with empty raw vector
writeBin(LETTERS, zz)
seek(zz, 0)
readLines(zz) # raw vector has embedded nuls
seek(zz, 0)
writeBin(letters[1:3], zz)
rawConnectionValue(zz)
close(zz)