Re: [Help-bash] Option execfail does not work in subshells

[David Niklas]

On Mon, 14 Aug 2017 10:52:14 -0400
Chet Ramey <address@hidden> wrote:
> On 8/9/17 1:50 PM, address@hidden wrote:
> > On Tue, 8 Aug 2017 17:04:12 +0200
> > "R. Diez" <address@hidden> wrote:  
> >>  
> >>> `execfail' only works when the shell is interactive.  Subshells are
> >>> not considered interactive shells.    
> >>
> >> But that is not what the documentation says:
> >>
> >> -----8<-----8<-----8<-----
> >> execfail
> >>
> >> If this is set, a non-interactive shell will not exit if it cannot 
> >> execute the file specified as an argument to the exec builtin
> >> command. An interactive shell does not exit if exec fails.
> >> -----8<-----8<-----8<-----  
> > <snip>
> > 
> > Notice that the two statements above are similar but not the *same*.  
> 
> The second sentence is intended to be the same as the first, but shorter
> to avoid saying the same thing multiple times; the only difference is
> whether or not the shell is interactive.

I'm used to manuals where if something is said differently, then it means
something different.
Why not use the short version for both?

> >> If this is set, a non-interactive shell will not exit if it cannot 
> >> execute the file specified as an argument to the exec builtin
> >> command.   
> > See the word "file", it's not equivalent to the word "function"[1].  
> 
> True, but it doesn't matter in this case, since the example does not
> have exec attempting to execute a shell function. `exec' always treats
> its argument as an executable file.

I mean that exec is a builtin which is a C function (I would imagine), and
is not a program, but a builtin. But that is probably another case
of reading too much into what was written.

> > Notice also that exec could fail for other reasons which are not
> > listed above but also not covered.  
> 
> But execfail doesn't cover those. The idea behind execfail is that if
> execve fails, the shell doesn't exit.
> 
> >> An interactive shell does not exit if exec fails.  
> > OTOH, an interactive shell would not exit if, for *any* reason exec
> > fails.  
> 
> You're reading too much into it. The only other reasons the builtin
> would fail is if given an invalid option or if the shell is restricted,
> and execfail doesn't act on those cases. The shell doesn't exit if
> those happen.

What about having incorrect permissions for the file, like read but no
exec, or exec but no read?
Or, how about an OOM condition?

Sincerely,
David