The GNU coding standards have had these two items since the beginning. First: Don't use the return value of @code{sprintf}. It returns the number of characters written on some systems, but not on all systems.
I don't see this mentioned in the Gnulib entry for sprintf at http://www.gnu.org/software/gnulib/manual/html_node/sprintf.html Is it still relevant? Second: Be aware that @code{vfprintf} is not always available. Again, I don't see it mentioned in http://www.gnu.org/software/gnulib/manual/html_node/vfprintf.html though seemingly nearly every other system has some kind of problem. Is it still relevant? (Reuben and I are trying to rewrite that node among others.) Thanks, karl