Here is the test case in a unix shell transcript: johnb@ilinux zsh: cat test.fqn ads.gamespy.com ads.enliven.com adserver.akqa.net ads.dogpile.com ads.fool.com johnb@ilinux zsh: sort test.fqn ads.dogpile.com ads.enliven.com adserver.akqa.net ads.fool.com ads.gamespy.com johnb@ilinux zsh: sort --version sort (GNU textutils) 2.0 Written by Mike Haertel. Copyright (C) 1999 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. johnb@ilinux zsh: type sort sort is /bin/sort It appears as though the -d option is enabled by default. Just my speculation though. My results on Solaris 2.6 appeared correct.
This was related to the locale stuff, which turned out to be more confusing than senseful. It's now (Rawhide/6.2b*) disabled by default.
So how do I disable -d in the interim?
For now, set the environmental variable LC_ALL to POSIX, and sort will work properly.