UNIX for Dummies Questions & Answers

Pls. advise why on AIX the exit status is always '0' and on Linux it is always '1' even if the I just created a new file.
I'm thinking if there is a background process monitoring the created 'file1' on AIX even if it is just a dummy or new file. How can I resolve this. (I need to justify that exit status must be the same )

#On AIX:
echo "test fuser" > file1

fuser file1; echo $?
file1:
0

# On Linux:
echo "test fuser" > file1

fuser file1; echo $?
1

What about the reverse test:

Code:

$ (sleep 1 >file & fuser file ; echo $? ; wait)
[1]     9098
file:     9098o
0
$

The fuser command was intended for viewing or testing stdout, not testing the exit code. My man pages do not say anything about exit or return codes. The function is to tell you if it is open, and somthing about the type of open, and who opened it. It may be a write or a read, or a memory map (see man mmap() / mmap64(), those great doorways to VM!).