Package: libc6 Version: 2.1.1-11 Although fmemopen() is in glibc2 source (glibc-2.1.1.orig/glibc-2.1.1/stdio/fme mopen.c) And referenced in glibc-doc libc_12.html#SEC210 It is absent from glibc2.1.1-11, which is annoying, since my program won't link. Colin.