on.exit {base}R Documentation

Function Exit Code


on.exit records the expression given as its argument as needing to be executed when the current function exits (either naturally or as the result of an error). This is useful for resetting graphical parameters or performing other cleanup actions.

If no expression is provided, i.e., the call is on.exit(), then the current on.exit code is removed.

on.exit is a primitive function so positional matching is used and names of supplied arguments are ignored.


on.exit(expr, add = FALSE)


expr an expression to be executed.
add if TRUE, add expr to be executed after any previously set expressions; otherwise (the default) expr will overwrite any previously set expressions.


Invisible NULL.


Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

See Also

sys.on.exit which returns the expression stored for use by on.exit() in the function in which sys.on.exit() is evaluated.


opar <- par(mai = c(1,1,1,1))

[Package base version 2.5.0 Index]