string to u_long and back using two functions, flags_to_string and
string_to_flags, which co-existed with 'ls'. As time has progressed
more and more other tools have used these private functions to
manipulate the file flags.
Recently I moved these functions from /usr/src/bin/ls to libutil,
but after some discussion with bde it's been decided that they
really ought to go in libc.
There are two already existing libc functions for manipulating file
modes: setmode and getmode. In keeping with these flags_to_string
has been renamed getflags and string_to_flags to setflags.
The manual page could probably be improved upon ;)