+ "Test for existence of the file. This is implied by each of the\n"
+ "other tests, so there's no need to combine it with them.\n"
+ "@end defvar\n"
+ "\n"
+ "It's important to note that @code{access?} does not simply\n"
+ "indicate what will happen on attempting to read or write a\n"
+ "file. In normal circumstances it does, but in a set-UID or\n"
+ "set-GID program it doesn't because @code{access?} tests the\n"
+ "real ID, whereas an open or execute attempt uses the effective\n"
+ "ID.\n"
+ "\n"
+ "A program which will never run set-UID/GID can ignore the\n"
+ "difference between real and effective IDs, but for maximum\n"
+ "generality, especially in library functions, it's best not to\n"
+ "use @code{access?} to predict the result of an open or execute,\n"
+ "instead simply attempt that and catch any exception.\n"
+ "\n"
+ "The main use for @code{access?} is to let a set-UID/GID program\n"
+ "determine what the invoking user would have been allowed to do,\n"
+ "without the greater (or perhaps lesser) privileges afforded by\n"
+ "the effective ID. For more on this, see ``Testing File\n"
+ "Access'' in The GNU C Library Reference Manual.")