ps_environ: Environment variables of a process

In r-lib/ps: List, Query, Manipulate System Processes

Environment variables of a process

Description

ps_environ() returns the environment variables of the process, in a named vector, similarly to the return value of Sys.getenv() (without arguments).

Usage

ps_environ(p = ps_handle())

ps_environ_raw(p = ps_handle())

Arguments

p	Process handle.

Details

Note: this usually does not reflect changes made after the process started.

ps_environ_raw() is similar to p$environ() but returns the unparsed "var=value" strings. This is faster, and sometimes good enough.

These functions throw a zombie_process error for zombie processes.

Value

ps_environ() returns a named character vector (that has a Dlist class, so it is printed nicely), ps_environ_raw() returns a character vector.

macOS issues

ps_environ() usually does not work on macOS nowadays. This is because macOS does not allow reading the environment variables of another process. Accoding to the Darwin source code, ps_environ will work is one of these conditions hold:

• You are running a development or debug kernel, i.e. if you are debugging the macOS kernel itself.

• The target process is same as the calling process.

• SIP if off.

• The target process is not restricted, e.g. it is running a binary that was not signed.

• The calling process has the com.apple.private.read-environment-variables entitlement. However adding this entitlement to the R binary makes R crash on startup.

Otherwise ps_environ will return an empty set of environment variables on macOS.

Issue 121 might have more information about this.

See Also

Other process handle functions: ps_children(), ps_cmdline(), ps_connections(), ps_cpu_times(), ps_create_time(), ps_cwd(), ps_descent(), ps_exe(), ps_handle(), ps_interrupt(), ps_is_running(), ps_kill(), ps_memory_info(), ps_name(), ps_num_fds(), ps_num_threads(), ps_open_files(), ps_pid(), ps_ppid(), ps_resume(), ps_send_signal(), ps_shared_libs(), ps_status(), ps_suspend(), ps_terminal(), ps_terminate(), ps_uids(), ps_username()

Examples

p <- ps_handle()
p
env <- ps_environ(p)
env[["R_HOME"]]

r-lib/ps documentation built on Sept. 8, 2024, 2:45 p.m.