Check required values for system environment variables

Individual session check function that inspects system environment variables. Session checkers can produce errors, warnings, or messages if requested.

Usage

check_required_sysenv(
  action = "warn",
  required_sysenv = NULL,
  action_on_pass = "none"
)

Arguments

action

Behavior to take if the status is not clean. Possible values are "error", "warn", "message", and "none". The default is action = "warn".

required_sysenv

A named list of required system environment variables. If any of these variables are missing or have different values to the required values, an action is triggered. The default is required_sysenv = NULL, which means there is nothing to compare against, so the check always passes.

action_on_pass

Behavior to take if the status is clean. Possible values are "message" and "none". The default is action_on_pass = "none".

Value

Invisibly returns an object of class sessioncheck_status.

See also

check_attached_packages(), check_loaded_namespaces(), check_globalenv_objects(), check_attached_environments(), check_sessiontime(), check_required_options(), check_required_locale(), check_working_directory()

Examples

check_required_sysenv(action = "message", required_sysenv = list(R_TEST = "value"))
#> ✖ Unexpected system environment variables:
#>     R_TEST: missing (expected value)

# a required variable that is present, but has a different value: reports
# the expected and actual values (R_HOME is set by R itself, so this is
# reliably a mismatch rather than a missing variable)
check_required_sysenv(action = "message", required_sysenv = list(R_HOME = "not-the-real-path"))
#> ✖ Unexpected system environment variables:
#>     R_HOME: expected not-the-real-path, got /opt/R/4.6.1/lib/R

# a required variable that is not set at all: reported as missing,
# rather than lumped in with the mismatched-value case above
check_required_sysenv(
  action = "message",
  required_sysenv = list(SESSIONCHECK_EXAMPLE_UNSET_VAR = "value")
)
#> ✖ Unexpected system environment variables:
#>     SESSIONCHECK_EXAMPLE_UNSET_VAR: missing (expected value)

# a required variable matching its current value: `action` only
# controls what happens when a problem *is* found, so use
# `action_on_pass = "message"` to confirm the clean result instead
check_required_sysenv(
  action = "none",
  required_sysenv = list(R_HOME = Sys.getenv("R_HOME")),
  action_on_pass = "message"
)
#> ✔ No unexpected system environment variables detected