cmd_run: Run the command.
cmd_help: Print the help document for this command.
cmd_background: Run the command in the background. This function is
provided for completeness. Instead of using this function, we recommend
using cmd_parallel(), which can run multiple commands in the background
while ensuring that all processes are properly cleaned up when the process
exits.
cmd_run(
command,
stdout = TRUE,
stderr = TRUE,
stdin = TRUE,
stdout_callback = NULL,
stderr_callback = NULL,
timeout = NULL,
spinner = FALSE,
verbose = TRUE
)cmd_help(
command,
stdout = TRUE,
stderr = TRUE,
stdout_callback = NULL,
stderr_callback = NULL,
verbose = TRUE
)
cmd_background(
command,
stdout = FALSE,
stderr = FALSE,
stdin = NULL,
verbose = TRUE
)
cmd_run: Exit status invisiblely.
cmd_help: The input command invisiblely.
cmd_background: A process object.
A command object.
Specifies how the output/error streams of the child process are handled. Possible values include:
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 stderr, use string "2>&1" to redirect it to the same connection (i.e.
pipe or file) as stdout.
For cmd_help(), use FALSE/NULL will do nothing, since it always want to
display the help document.
For cmd_background(), connection cannot be used, and TRUE and "|"
will fallback to the empty string "".
When using a connection (if not already open) or a string, wrapping it
with I() prevents overwriting existing content.
should the input be diverted? Possible values include:
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().
Possible values include:
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.
Timeout in seconds. This is a limit for the elapsed time running command in the separate process.
Whether to show a reassuring spinner while the process is running.
A single boolean value indicating whether the command execution should be verbose.
cmd_wd()/cmd_envvar()/cmd_envpath()/cmd_conda()
cmd_on_start()/cmd_on_exit()
cmd_on_succeed()/cmd_on_fail()
cmd_parallel()