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Re: Should I worry about "Inappropriate ioctl for device"?
by choroba (Cardinal) on Aug 07, 2020 at 13:03 UTC
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Inspecting $! only makes sense when you know it was set, e.g. in open ... or die $!;. If you didn't run any function that sets $!, or you ran it but it didn't fail, the contents of $! could be anything.
Somehow mentioned in $!.
map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]
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I was just wondering if this was something I should go through all my work and fix now, or can it wait until later? Is it a critical flaw in my writing? Could an inappropriate use of $! bite me sooner rather than later?
I have been tacking $! onto the end of every string I use in die and warn since I was told to use it there. I had not looked into what it was doing or how it worked. I have been using it because I was told to use it on one occasion, probably when I first used die with an open.
Please forgive me for not knowing my use of $! was not appropriate in the case in my OP. Should this be urgent, I will go through my work and make the needed changes.
My OS is Debian 10 (Buster); my perl versions are 5.28.1 local and 5.16.3 or 5.30.0 on web host depending on the shebang.
No matter how hysterical I get, my problems are not time sensitive. So, relax, have a cookie, and a very nice day!
Lady Aleena
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If you use it just in the messages coming from die or warn, it's confusing, but not critical. Basing the program flow on the value would be a critical problem, though:
...
die $! if $!; # Can stop your program for no real reason.
map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]
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Lady_Aleena:
If you didn't run any function that sets $!, or you ran it but it didn't fail, the contents of $! could be anything.
E.g.:
c:\@Work\Perl\monks>perl -wMstrict -le
"print 0+$!, qq{ == '$!'};
"
9 == 'Bad file descriptor'
Give a man a fish: <%-{-{-{-<
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Re: Should I worry about "Inappropriate ioctl for device"?
by hippo (Bishop) on Aug 07, 2020 at 12:37 UTC
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That's merely the contents of $! at the time your die is called. You need to find out what it is prior to this which is setting $! to that string then you'll be in a position to fix it.
You are using warnings, I presume?
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Re: Should I worry about "Inappropriate ioctl for device"?
by Lady_Aleena (Priest) on Aug 09, 2020 at 00:33 UTC
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Now I am confused a bit. The $! in the following, when it died, did not tell me that I was using ioctl inappropriately. The reason I am confused is that the lines of code in my OP were inside-out conditionals (don't remember where I got that term), but the code below is just a conditional too.
My OS is Debian 10 (Buster); my perl versions are 5.28.1 local and 5.16.3 or 5.30.0 on web host depending on the shebang.
No matter how hysterical I get, my problems are not time sensitive. So, relax, have a cookie, and a very nice day!
Lady Aleena
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Nothing in the code you show does anything that would give $! a meaningful value. The value $! actually has at the moment the code shown is executed was either set in some previous operation that gave $! a meaningful value (update: see this), or else it's the value $! happened to have at program startup (update: see this), i.e., random. Either way, its value is meaningless.
Update: Consider this code:
c:\@Work\Perl\monks>perl -wMstrict -le
"my $year = 987;
$! = 0;
if ($year !~ /\d{4}/) { die qq{Idiot!, use 4 digit year. Stopped '$!'
+} }
"
Idiot!, use 4 digit year. Stopped '' at -e line 1.
Now try assigning different values (1, 2, 3, ...) to $! and see what messages you get. The messages you're seeing in your posted code are just cruft.
Give a man a fish: <%-{-{-{-<
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I forgot to mention, I already took $! out of that code. I am still a little confused by why I would get a message about inappropriate use of ioctl in one script but not another.
Also, I just checked the rest of my code and removed all the other inappropriate uses of ioctl that I could find. All those that are left are with opens.
My OS is Debian 10 (Buster); my perl versions are 5.28.1 local and 5.16.3 or 5.30.0 on web host depending on the shebang.
No matter how hysterical I get, my problems are not time sensitive. So, relax, have a cookie, and a very nice day!
Lady Aleena
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sub four_digit_year {
my $year = shift;
if ( $year !~ /\d{4}/ ) {
return; # undef
}
return $year;
}
Then check if the result of your sub call is defined and die with some custom error message if not.
And probably you may find a more robust recipe on PM how to test if some date is valid.
Best regards, Karl
«The Crux of the Biscuit is the Apostrophe»
perl -MCrypt::CBC -E 'say Crypt::CBC->new(-key=>'kgb',-cipher=>"Blowfish")->decrypt_hex($ENV{KARL});'Help
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Re: Should I worry about "Inappropriate ioctl for device"?
by Anonymous Monk on Aug 08, 2020 at 02:55 UTC
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No, don't ignore this. You have a bug. Better now than later. | [reply] |
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lol. what would you know about it? lol
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