These functions are currently experimental and will change in the future. Note that processx connections are not compatible with R's built-in connection system.
conn_create_fd(fd, encoding = "", close = TRUE) conn_file_name(con) conn_create_pipepair(encoding = "", nonblocking = c(TRUE, FALSE)) conn_read_chars(con, n = -1) # S3 method for processx_connection conn_read_chars(con, n = -1) processx_conn_read_chars(con, n = -1) conn_read_lines(con, n = -1) # S3 method for processx_connection conn_read_lines(con, n = -1) processx_conn_read_lines(con, n = -1) conn_is_incomplete(con) # S3 method for processx_connection conn_is_incomplete(con) processx_conn_is_incomplete(con) conn_write(con, str, sep = "\n", encoding = "") # S3 method for processx_connection conn_write(con, str, sep = "\n", encoding = "") processx_conn_write(con, str, sep = "\n", encoding = "") conn_create_file(filename, read = NULL, write = NULL) conn_set_stdout(con, drop = TRUE) conn_set_stderr(con, drop = TRUE) conn_get_fileno(con) conn_disable_inheritance() # S3 method for processx_connection close(con, ...) processx_conn_close(con, ...) is_valid_fd(fd)
Integer scalar, a Unix file descriptor.
Encoding of the readable connection when reading.
Whether to close the OS file descriptor when closing the connection. Sometimes you want to leave it open, and use it again in a
conn_create_fdcall. Encoding to re-encode
strinto when writing.
Processx connection object.
Whether the pipe should be non-blocking. For
conn_create_pipepair()it must be a logical vector of length two, for both ends of the pipe.
Number of characters or lines to read. -1 means all available characters or lines.
Character or raw vector to write.
Separator to use if
stris a character vector. Ignored if
stris a raw vector.
File name. For
conn_create_pipe()on Windows, a
\\?\pipeprefix is added to this, if it does not have such a prefix. For
conn_create_pipe()it can also be
NULL, in which case a random file name is used via
Whether the connection is readable.
Whethe the connection is writeable.
Whether to close the original stdout/stderr, or keep it open and return a connection to it.
Extra arguments, for compatibility with the
close()generic, currently ignored by processx.
conn_create_fd() creates a connection from a file descriptor.
conn_file_name() returns the name of the file associated with the
connection. For connections that do not refer to a file in the file
system it returns
NA_character(). Except for named pipes on Windows,
where it returns the full name of the pipe.
conn_create_pipepair() creates a pair of connected connections, the
first one is writeable, the second one is readable.
conn_read_chars() reads UTF-8 characters from the connections. If the
connection itself is not UTF-8 encoded, it re-encodes it.
conn_read_lines() reads lines from a connection.
FALSE if the connection surely has no
conn_write() writes a character or raw vector to the connection.
It might not be able to write all bytes into the connection, in which
case it returns the leftover bytes in a raw vector. Call
again with this raw vector.
conn_create_file() creates a connection to a file.
conn_set_stdout() set the standard output of the R process, to the
conn_set_stderr() set the standard error of the R process, to the
conn_get_fileno() return the integer file desciptor that belongs to
conn_disable_inheritance() can be called to disable the inheritance
of all open handles. Call this function as soon as possible in a new
process to avoid inheriting the inherited handles even further.
The function is best effort to close the handles, it might still leave
some handles open. It should work for
fd is a valid open file
descriptor. You can use it to check if the R process has standard
input, output or error. E.g. R processes running in GUI (like RGui)
might not have any of the standard streams available.
If a stream is redirected to the null device (e.g. in a callr subprocess), that is is still a valid file descriptor.