Debian - /etc/passwd, vim, vipw
 

I know that the vipw command, as man pages say, "edits the password file after setting the appropriate locks".

I tried opening two terminals and issuing "vipw" on both. The first time I got in the passwd file as expected, the second time I got an error message, as expected.

I then issued "vipw" in one terminal and "vim /etc/passwd" in the other. The first time I got in the passwd file as expected, the second time I... also entered the passwd file and was able to edit and also to save it!

Am I missing something or those locks are not so "appropriate"?

Not sure but i think the Default editor is allowed to edit the file by bypassing the locks but i may be wrong

and i think in your case vi is the default editor