The child process is started in the background, and the function return immediately.

rcmd_bg(
cmd,
cmdargs = character(),
libpath = .libPaths(),
stdout = "|",
stderr = "|",
poll_connection = TRUE,
repos = default_repos(),
system_profile = FALSE,
user_profile = "project",
env = rcmd_safe_env(),
wd = ".",
supervise = FALSE,
...
)

## Arguments

cmd Command to run. See R --help from the command line for the various commands. In the current version of R (3.2.4) these are: BATCH, COMPILE, SHLIB, INSTALL, REMOVE, build, check, LINK, Rprof, Rdconv, Rd2pdf, Rd2txt, Stangle, Sweave, Rdiff, config, javareconf, rtags. Command line arguments. The library path. Optionally a file name to send the standard output to. Optionally a file name to send the standard error to. It may be the same as stdout, in which case standard error is redirected to standard output. It can also be the special string "2>&1", in which case standard error will be redirected to standard output. Whether to have a control connection to the process. This is used to transmit messages from the subprocess to the parent. The repos option. If NULL, then no repos option is set. This options is only used if user_profile or system_profile is set FALSE, as it is set using the system or the user profile. Whether to use the system profile file. Whether to use the user's profile file. If this is "project", then only the profile from the working directory is used, but the R_PROFILE_USER environment variable and the user level profile are not. See also "Security considerations" below. Environment variables to set for the child process. Working directory to use for running the command. Defaults to the current working directory. Whether to register the process with a supervisor. If TRUE, the supervisor will ensure that the process is killed when the R process exits. Extra arguments are passed to the processx::process constructor.

## Value

It returns a process object.

## Security considerations

callr makes a copy of the user's .Renviron file and potentially of the local or user .Rprofile, in the session temporary directory. Avoid storing sensitive information such as passwords, in your environment file or your profile, otherwise this information will get scattered in various files, at least temporarily, until the subprocess finishes. You can use the keyring package to avoid passwords in plain files.

Other R CMD commands: rcmd_copycat(), rcmd()