The old inappropriate ioctl bugaboo again, in mod

jcabraham has asked for the wisdom of the Perl Monks concerning the following question:

Hi all, I have some code I'm porting to mod_perl2, running on ubuntu jaunty. The code is below. In a request handler, I'm simply opening a file, writing a little data, closing it. Simplicity itself. This code ran for years and years on mod_perl1. I ported it unchanged (this snippet, unchanged -- I made all the appropriate mod_perl2 conversions), and now running it causes intermittent "inappropriate ioctl for device" errors. I read somewhere that this may have to do with mod_perl2 needing to retie filehandles, but that would seem like a big change from mp1. Any thoughts?

my $file = "/tmp/foobar.txt"; #dir perms 777
open (FILE, ">$file") or die "ERROR: can't create $file: $!\n";
print FILE "the quick brown fox, etc.\n" or die "ERROR: $!\n";
close FILE or die "ERROR: closing $file $!\n";
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Re: The old inappropriate ioctl bugaboo again, in mod_perl2 by almut (Canon) on Apr 27, 2010 at 21:59 UTC
Maybe the `print` is intermittently failing for some reason... I think `print` doesn't necessarily set `$!` when returning false, so when you effectively execute the following code (in case of error), you'd get `my $file = "/tmp/foobar.txt"; #dir perms 777 open (FILE, ">$file") or die "ERROR: can't create $file: $!\n"; 0 or die "ERROR: $!\n"; # <--- dies with "ERROR: Inappropriate ioc +tl for device"` [download] In other words, what you see might be just the last errno that occurred, which is the regular (nothing-to-worry-about) ENOTTY from the `ioctl` belonging to the preceding `open`: `$ strace ./837195.pl ... open("/tmp/foobar.txt", O_WRONLY\|O_CREAT\|O_TRUNC, 0666) = 3 ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, 0x7fffa2ebce90) = -1 ENOTTY (I +nappropriate ioctl for device) lseek(3, 0, SEEK_CUR) = 0 fstat(3, {st_mode=S_IFREG\|0600, st_size=0, ...}) = 0 fcntl(3, F_SETFD, FD_CLOEXEC) = 0 write(3, "the quick brown fox, etc.\n", 26) = 26 close(3) = 0 exit_group(0) = ?` [download] Of course, you'd still have to find the cause for the failing print, but it might have nothing to do with `ioctl`...	[reply] [d/l] [select]
Re: The old inappropriate ioctl bugaboo again, in mod_perl2 by Corion (Patriarch) on Apr 27, 2010 at 21:24 UTC
Personally, I would try lexical filehandles instead of global filehandles, especially as you don't seem to be `local`izing `FILE`. If circumstances collude, you might or might not close the `FILE` filehandle for some other routine while you're doing your logging. Alternatively, maybe it's a hardware problem and the device in question is (going) bad and has intermittent errors?	[reply] [d/l] [select]
Re: The old inappropriate ioctl bugaboo again, in mod_perl2 by ikegami (Patriarch) on Apr 27, 2010 at 21:26 UTC
it causes intermittent "inappropriate ioctl for device" errors. Perl regularly makes calls that return that error, but that's not a problem. Do you mean "it dies with intermittent 'inappropriate ioctl for device' errors."?	[reply]
Re: The old inappropriate ioctl bugaboo again, in mod_perl2 by swartz (Beadle) on May 12, 2010 at 22:43 UTC
Might be related to the longstanding Apache/mod_perl 2 bug in which it closes STDOUT but doesn't reopen it. See the thread at http://marc.info/?l=apache-modperl&m=126296015910250&w=2	[reply]