John Poltorak writes:
>
> Can anyone explain what this code in autoupdate does? :-
>
>
> my $macros = new Autom4te::XFile ("$autoconf"
> . " --trace AU_DEFUN:'AU:\$f:\$1'"
> . " --trace define:'AC:\$f:\$1'"
> . " --melt /dev/null |");
This is just one command, split over several lines for readability.
The dot operator connects all these strings into one:
$autoconf --trace AU_DEFUN:'AU:\$f:\$1' --trace define:'AC:\$f:\$1' --melt
/dev/null |"
So, it runs the above command (everything before "|") and reads its output
(the effect of the "|"). The /dev/null part specifies the input file
$autoconf should read. $macros is a filehandle that is later read from,
line by line.
(I could be wrong, of course - I haven't familiarised myself with autoconf
2 1/2 yet ;-)
> It appears to be causing the error msg:-
>
> no such file or directory: /dev/null
>
> on OS/2. This may be due to a bug in sh or Perl on OS/2 but it's difficult
> to debug. What exactly is the purpose of '/dev/null |' above, and can I
> try using something else instead just to get a pointer to the underlying
> problem?
Probably a bug in your sh.
