"Inappropriate ioctl for device"

Question

I have a Perl script running on AIX.

The script is trying to open the file from a specific directory and it cannot read the file because the file does not have read permission, but I get another error saying inappropriate ioctl for device .

Shouldn't it say something like no read permissions for file or something like that?

What does this inappropriate ioctl for device message mean?

How can i fix this?

EDIT: This is what I found when I did strace .

 open ("/ local / logs / xxx / xxxxServer.log", O_WRONLY | O_CREAT | O_APPEND | O_LARGEFILE, 
     0666) = 4 _llseek (4, 0, [77146], SEEK_END) = 0
 ioctl (4, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbffc14f8) = -1 ENOTTY 
     (Inappropriate ioctl for device)

Answer 1

Most likely, this means that open did not work.

When Perl opens the file, it checks if the file is TTY (so that it can respond to the -T $fh filetest operator) by issuing TCGETS ioctl against it. If the file is a regular file and not tty, ioctl fails and sets errno to ENOTTY (string value: "ioctl mismatch for device"). According to ysth, the most common cause of an unexpected value in $! is checking it when it is invalid, that is, anywhere except immediately after the syscall failure, so it is critical to check the result codes of your operations.

If open really returned false for you and you found ENOTTY at $! , then I would think of it as a small mistake (giving a useless value of $! ), but I would also be very curious how this happened. The output of the code and / or farm will be great.

Answer 2

Odd errors, such as "inappropriate ioctl for the device," are usually the result of checking $! at some point other than immediately after a system call failure. If you show your code, I'm sure someone will quickly point out your error.

Answer 3

"files" on * nix type systems is a very abstract concept.

They can be disk areas organized by the file system, but they can also be a network connection, a bit of shared memory, a buffer output from another process, screen, or keyboard.

In order for perl to be really useful, it reflects this model very closely and does not process files, emulating magnetic tape, as 4gls does.

Thus, he tried to perform the “IOCTL” operation “open for writing” in a file descriptor that does not allow writing operations that are unacceptable IOCTL operations for this device / file.

The easiest thing to do is stick to the or die 'Cannot open $myfile' statement at the end of your discovery, and you can choose your own meaningful message.

Answer 4

"Incorrect ioctl for device" is the error string for the ENOTTY error. Previously, this was caused by attempts to configure the properties of the terminal (for example, echo mode) in a file descriptor that was not a terminal (but, say, a regular file), therefore, ENOTTY. More generally, it starts when ioctl is run on a device that does not support this ioctl, therefore the error line.

To find out what ioctl is doing, which fails, and in which file descriptor, run the script under strace / truss. You will learn ENOTTY, and then the actual error message is printed. Then find out which file number was used and which open () call returned that file number.

Answer 5

Eureka moment!

I had this error before.

You called the perl debugger with something like: -

 perl -d yourprog.pl > log.txt 

If so, what happens is: perl debug tries to request and possibly reset the width of the terminal. When stdout is not a terminal, it fails with an IOCTL message.

An alternative would be your debugging session forever, because you do not see tooltips for instructions.

Answer 6

I just fixed this error. See https://rt.perl.org/Ticket/Display.html?id=124232

When we push the buffer layer to PerlIO and perform an isatty () failure check which obviously does not work in all normal files, the errno ENOTTY is ignored.

Answer 7

Start this error today by trying to use the code to delete the folder / files that live in the Windoze 7 window set as a share on the Centos server. Got the wrong icotl for the device error and tried everything that came to mind. Read about each post on the network related to this.

Obviously, the problem was isolated from the installed Windoze resource on the Linux server. I looked at the resolution of the file in the Windoze window and noted that the files have their read-only permissions.

Changed them, returned to the Linux server and everything worked as expected. This may not be the solution for most, but hopefully it will save time.

Answer 8

I tried the following code that seemed to work:

 if(open(my $FILE, "<File.txt")) { while(<$FILE>){ print "$_";} } else { print "File could not be opened or did not exists\n"; } 

Answer 9

Since this is a fatal error and it is also difficult to debug it, maybe the fix could be placed somewhere (in the provided command line?):

 export GPG_TTY=$(tty) 

From: https://github.com/keybase/keybase-issues/issues/2798