Execute a list of commands

Usage

cmd_parallel(
  ...,
  stdouts = FALSE,
  stderrs = FALSE,
  stdins = NULL,
  stdout_callbacks = NULL,
  stderr_callbacks = NULL,
  timeouts = NULL,
  threads = NULL,
  verbose = TRUE
)

Arguments

...

A list of command object.

stdouts, stderrs

Specifies how the output/error streams of the child process are handled. One of or a list of following values:

FALSE/NULL: Suppresses the output/error stream.
TRUE: Prints the child process output/error to the R console. If a standard output/error stream exists, "" is used; otherwise, "|" is used.
string: An empty string "" inherits the standard output/error stream from the main R process (Printing in the R console). If the main R process lacks a standard output/error stream, such as in RGui on Windows, an error is thrown. A string "|" prints to the standard output connection of R process (Using cat()). Alternative, a file name or path to redirect the output/error. If a relative path is specified, it remains relative to the current working directory, even if a different directory is set using cmd_wd().
connection: A writable R connection object. If the connection is not open(), it will be automatically opened.

For stderrs, use string "2>&1" to redirect it to the same connection (i.e. pipe or file) as stdout.

When a single file path is specified, the stdout/stderr of all commands will be merged into this single file.

stdins

should the input be diverted? One of or a list of following values:

FALSE/NULL: no standard input.
TRUE: If a standard input stream exists, "" is used; otherwise, NULL is used.
string: An empty string "" inherits the standard input stream from the main R process. If the main R process lacks a standard input stream, such as in RGui on Windows, an error is thrown. Alternative, a file name or path to redirect the input. If a relative path is specified, it remains relative to the current working directory, even if a different directory is set using cmd_wd().

stdout_callbacks, stderr_callbacks

One of or a list of following values:

NULL: no callback function.
function: A function invoked for each line of standard output or error. Non-text (non-character) output will be ignored. The function should accept two arguments: one for the standard output or error and another for the running process object.

timeouts

Timeout in seconds. Can be a single value or a list, specifying the maximum elapsed time for running the command in the separate process.

threads

Number of threads to use.

verbose

A single boolean value indicating whether the command execution should be verbose.

Value

A list of exit status invisiblely.

Execute a list of commands

Usage

Arguments

Value

See also