terminating: Terminating a Child Process.
In subprocess: Manage Sub-Processes in R

Description Usage Arguments Format Details Value See Also

These functions give access to the state of the child process and to its exit status (return code).

The timeout parameter can take one of three values:

0 which means no timeout
-1 which means "wait until there is data to read"
a positive integer, which is the actual timeout in milliseconds

TIMEOUT_INFINITE denotes an "infinite" timeout (that is, wait until response is available) when waiting for an operation to complete.

TIMEOUT_IMMEDIATE denotes an "immediate" timeout (in other words, no timeout) when waiting for an operation to complete.

process_wait(handle, timeout = TIMEOUT_INFINITE)

process_state(handle)

process_return_code(handle)

TIMEOUT_INFINITE

TIMEOUT_IMMEDIATE

`handle`	Process handle obtained from `spawn_process`.
`timeout`	Optional timeout in milliseconds.

An object of class integer of length 1.

process_wait() checks the state of the child process by invoking the system call waitpid() or WaitForSingleObject().

process_state() refreshes the handle by calling process_wait() with no timeout and returns one of these values: "not-started". "running", "exited", "terminated".

process_return_code() gives access to the value returned also by process_wait(). It does not invoke process_wait() behind the scenes.

process_wait() returns an integer exit code of the child process or NA if the child process has not exited yet. The same value can be accessed by process_return_code().

spawn_process(), process_read() signals()

subprocess documentation built on May 2, 2019, 4:04 p.m.