External R Process

An R process that runs in the background. This is an R6 class that extends the processx::process class. The process starts in the background, evaluates an R function call, and then quits.

Super class

processx::process -> r_process

Methods

Public methods

• r_process$new()

• r_process$get_result()

• r_process$finalize()

• r_process$clone()

Inherited methods

• processx::process$as_ps_handle()
• processx::process$format()
• processx::process$get_cmdline()
• processx::process$get_cpu_times()
• processx::process$get_error_connection()
• processx::process$get_error_file()
• processx::process$get_exe()
• processx::process$get_exit_status()
• processx::process$get_input_connection()
• processx::process$get_input_file()
• processx::process$get_memory_info()
• processx::process$get_name()
• processx::process$get_output_connection()
• processx::process$get_output_file()
• processx::process$get_pid()
• processx::process$get_poll_connection()
• processx::process$get_start_time()
• processx::process$get_status()
• processx::process$get_username()
• processx::process$get_wd()
• processx::process$has_error_connection()
• processx::process$has_input_connection()
• processx::process$has_output_connection()
• processx::process$has_poll_connection()
• processx::process$interrupt()
• processx::process$is_alive()
• processx::process$is_incomplete_error()
• processx::process$is_incomplete_output()
• processx::process$is_supervised()
• processx::process$kill()
• processx::process$kill_tree()
• processx::process$poll_io()
• processx::process$print()
• processx::process$read_all_error()
• processx::process$read_all_error_lines()
• processx::process$read_all_output()
• processx::process$read_all_output_lines()
• processx::process$read_error()
• processx::process$read_error_lines()
• processx::process$read_output()
• processx::process$read_output_lines()
• processx::process$resume()
• processx::process$signal()
• processx::process$supervise()
• processx::process$suspend()
• processx::process$wait()
• processx::process$write_input()

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Method new()

Start a new R process in the background.

Usage

r_process$new(options)

Arguments

options

A list of options created via r_process_options().

Returns

A new r_process object.

---

Method get_result()

Return the result, an R object, from a finished background R process. If the process has not finished yet, it throws an error. (You can use wait() method (see processx::process) to wait for the process to finish, optionally with a timeout.) You can also use processx::poll() to wait for the end of the process, together with other processes or events.

Usage

r_process$get_result()

Returns

The return value of the R expression evaluated in the R process.

---

Method finalize()

Clean up temporary files once an R process has finished and its handle is garbage collected.

Usage

r_process$finalize()

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Method clone()

The objects of this class are cloneable with this method.

Usage

r_process$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Examples

if (FALSE) {
## List all options and their default values:
r_process_options()

## Start an R process in the background, wait for it, get result
opts <- r_process_options(func = function() 1 + 1)
rp <- r_process$new(opts)
rp$wait()
rp$get_result()
}