Gustav H Meyer writes:
> >> The close statement is as follows:
> >> 85 close(MAIL) or die "Can't close pipe to $sendmail: $!\n";
> >>
> >> As you can see the value of $! is passed on to the browser together
> >> with the message. But unfortunately I can see no value to speak of.
> >> In other words the value must be blank.
[...]
> 459 open(MAIL,"| $sendmail -t") or &error("Couldn't
> open sendmail process: $!");
[...]
> 472 close(MAIL) or &error("Can't close pipe to $send mail: $!");
I haven't been following this thread in detail but this caught my eye.
Do you realise that if the piped program exits with a non-zero return
code then close(MAIL) will return false and set $! to 0 numerically
(a blank string if you use it as a string)? It will also put the exit
code of the subprogram in $? for you. This is all documented:
% man perlfunc
close FILEHANDLE
close Closes the file or pipe associated with the file
handle, returning true only if stdio successfully
[...]
If the file handle came from a piped open `close'
will additionally return false if one of the other
system calls involved fails or if the program
exits with non-zero status. (If the only problem
was that the program exited non-zero `$!' will be
set to `0'.) Closing a pipe also waits for the
process executing on the pipe to complete, in case
you want to look at the output of the pipe after
wards, and implicitly puts the exit status value
of that command into `$?'.
--Malcolm
--
Malcolm Beattie <mbeattie@???>
Unix Systems Programmer
Oxford University Computing Services
