Hello Chris
On 07/16/2016 05:11 AM, Chris Gassib wrote:
Description:
The manual entry for KDGETMODE specifies "argp points to a long which
is set to one of the above values." At least on x86_64-bit Fedora24,
the text should probably specify argp is an int (32-bit), rather than
a long (64-bit).
Repo:
Open a file descriptor to the local console, and execute some code like the following:
long arg = -1;
if (-1 == ioctl(fd, KDGETMODE, &arg)) { return -1; }
printf("KDGETMODE: 0x%lx\n", arg);
Now try this version:
int arg = -1;
if (-1 == ioctl(fd, KDGETMODE, &arg)) { return -1; }
printf("KDGETMODE: 0x%x\n", arg);
Result:
The first version gives this result:
KDGETMODE: 0xffffffff00000001
The second version gives this result:
KDGETMODE: 0x1
Expected:
Either documentation incorrect, or the API is. One of them should be
changed so they match, or perhaps the documentation should specify
that it only applies to the 32-bit version.
Reading the source confirms your point, and it's the documentation that
should be fixed. I've made that change. Thanks for the report.
Cheers,
Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
--
To unsubscribe from this list: send the line "unsubscribe linux-man" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
