eval — Evaluate expression
eval is a way to make up commands and functions at execution time.
You do not gain much by using this function during an interactive
session, however it can be very useful when called from a script.
The expression contained in the string argument is evaluated without
regard to local functions. Essentially what occurs is equivalent to
replacing the eval function with the contents of the
string in a global context. Any assignments or variable
modifications will effect the global symbol table only.
eval does not have any knowledge of local variables. Thus if
you use eval within a user-defined function, you must be
careful not to reference that function's arguments or local variables.
This is not an built-in function. This function
is normally loaded on start-up from the eval.r file in the
standard rlib directory. Use of the -r option, incorrectly
setting the RLAB_LIB_DIR environmental variable, or modifying
eval.r may make this function unavailable.
Subsections