I did ~/pythonsource1/python2.6-2.6.5$ find -D rates . -type dand gotPredicate success rates after completion:[need type] -type d [0.4] [280/4350=0.0643678] -a [0.4] [280/4350=0.0643678] -print [1] [280/280=1] What does the [0.4] indicate ?
Explain the output of -D rates in GNU find
linux;find;utilities
Judging from the source code, the numbers in square brackets are the a priori estimated success rate for a given predicate.  That is, the first [0.4] is an estimate of the probability that the -type d will evaluate to true.  It may be used to determine the order in which the terms of the predicate are evaluated.  You can find more in findutils-4.4.2/find/parser.c, findutils-4.4.2/find/tree.c and findutils-4.4.2/find/pred.c.