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linuxgoioctl

How to set immutable file attribute

How can I set the immutable attribute for a file with Go?

I need a function that set/unset this attribute on a file, similar to chattr +i file

I found this: IoctlSetInt

how to use it?

    file, err := os.Open("file")

    if err != nil {
        fmt.Printf("%s\n", err)
        return
    }


    err = unix.IoctlSetInt(int(file.Fd()), unix.PERF_EVENT_IOC_MODIFY_ATTRIBUTES, unix.STATX_ATTR_IMMUTABLE)

    if err != nil {
        fmt.Printf("%s\n", err)
    }

error: inappropriate ioctl for device

SOLUTION

I found a pice of code in snapd's repo.

Solution

  • I'm not sure you're using the right ioctl here... At least chattr and the solution of Setting Immutable Flag using ioctl() in C use FS_IOC_SETFLAGS (you can see what chattr does using strace). You can have a look at /usr/include/linux/fs.h, notably the big comment about "Inode flags", for more information.