Jonny Grant wrote: > Please keep my email address in any replies > > Bob Proulx wrote: > > Jonny Grant wrote: > > > Yes, it's a known limitation of POSIX that it uses a shared error code for > > > both files and directors, ENOENT. Which without programmers handling and > > > checking the stat() flags, means the error isn't completely clear in the > > > case where a file or dir does exist. > > > > I don't see how POSIX is involved in this. Blaming POSIX is a > > complete non-sequitur here. > > Why do you feel it isn't?
The "No such file or directory" message I see in the Unix v7 code circa 1979 and therefore appeared at least that early but probably was there since the beginning. That predates the first POSIX standard by many years. File errlst.c: char *sys_errlist[] = { "Error 0", "Not owner", "No such file or directory", ... File errno.h: #define ENOENT 2 > > > I imagine we have spoken already for longer about this, than it would have > > > been to fix it. > > > > I see no bug to fix here. However I fear that trying to fix an > > imaginary one would introduce a bug here. > > How can an easy update to clarify message "No such file or directory" > introduce a bug? Because "No such file or directory" is the exact error message that corresponds to the error returned by the OS kernel as defined by the system in the /usr/include definition file which is used by all programs. It is an important commonality. All programs should say the same thing for that error. If every program created a different error message for that error then it would be hard to learn what each and every program said for each and every individual possible error. OMG! That would be horrible. Changing it to make it something different would obscure the error that is being returned by the OS. It would make this one program say something different for that error than other programs. Different makes it harder to understand. Let's look at your cases again. > $ cd missingdir > bash: cd: missingdir: No such file or directory Why do you think that is undesirable? That is the system error. The requested "missingdir" to change directory to failed because there is no entry by that name, uh, no such file or directory by that name. :-) > Likewise, software that deals with directories, or in the case of > "cd" in bash, trying to change directory, can very easily report "No > such directory" I think some of the problem might be that you are thinking that directories are not files. But in Unix like systems everything is a file. (And in a Linux like system everything is a file system. It's a joke but also with some truth to it.) If I were writing that error message I may have said "No such entry" since that is the literal error. Meaning directory entry. But I could see having written "No such file", stopped there without the directory hint, and defended it as being correct because everything is a file. But I forgive them for helping the user out a little by hinting that no files, not even special files such as directories, were found. Directories are files. They are special files. But files just the same. https://en.wikipedia.org/wiki/Unix_file_types "The most common special file is the directory." Let's try some other shells to see what error messages they produce. $ ksh $ cd nonexistent ksh: cd: nonexistent: [No such file or directory] $ mksh $ cd nonexistent mksh: cd: /home/rwp/nonexistent: No such file or directory $ ^D $ zsh % cd nonexistent cd: no such file or directory: nonexistent $ csh % cd nonexistent nonexistent: No such file or directory. % exit We can also try a programming solution too just to double check what error message is provided using a one-liner. $ perl -e 'chdir("doesnotexist") or die "$!\n";' No such file or directory It is good that everyone uses the same error messages. Let's look at your other case. > $ ./main > -bash: ./main: No such file or directory $ ksh $ ./nonexistent ksh: ./nonexistent: not found [No such file or directory] $ mksh $ ./nonexistent mksh: ./nonexistent: not found $ $ zsh % ./nonexistent zsh: no such file or directory: ./nonexistent % $ csh % ./non-existent ./non-existent: Command not found. % exit It looks like mksh and csh are the odd ones out here. Bob