I asked:
#: > [What were the rules for ETEXT again...?  You can have it open for
#: > writing or executing, but you can't have it open for both, and read
#: > permission is immaterial.  Or something like that.]
#: 

der Mouse replied:
#: Something like that, except I think it's that when you try to open for
#: write, if the file is backing a text segment that's in use, you get
#: ETXTBUSY.  I don't recall anything that would prevent executing a file
#: that's still got a file descriptor open for write.  (But on the other
#: hand, the last source code I looked at this under was 4.3BSD.)

Which is interesting, since under 4.3BSD (stock), you couldn't execute
a program you were currently running under dbx or adb.

				--*greywolf;

#: 
#: 					der Mouse
#: 
#: 			    mouse@collatz.mcrcim.mcgill.edu
#: