Error....

[atti2000]

gcc -Wall -o keyboard_mouse keyboard_mouse.c

keyboard_mouse.c: In function 'main':
keyboard_mouse.c:74: error: 'for' loop initial declarations are only allowed in C99 mode
keyboard_mouse.c:74: note: use option -std=c99 or -std=gnu99 to compile your code
keyboard_mouse.c:134: error: 'for' loop initial declarations are only allowed in C99 mode
keyboard_mouse.c:232: error: storage size of 'setup_data' isn't known
keyboard_mouse.c:239: error: 'UI_DEV_SETUP' undeclared (first use in this function)
keyboard_mouse.c:239: error: (Each undeclared identifier is reported only once
keyboard_mouse.c:239: error: for each function it appears in.)

OS : CentOS 6.10

Help me....

[SalmonChris]

The error messages about lines 74 and 134 are easily fixed by adding -std=c99 to the compilation line. Newer versions of gcc seem to make C99 standard, but apparently the version you're using makes the older C90 standard the default. The C90 standard is the ANSI C standard adopted in 1990 and the C99 standard is the ANSI C standard adopted in 1999.

The other errors aren't so easily fixed. The fundamental problem is that the version of CentOS you're using uses an older, incompatible method of doing device setup.

The present keyboard_mouse.c code uses the UI_DEV_SETUP ioctl to set up the device. This ioctl was added to the kernel in 2015. Before that, a different method was used to set up the device: using write() to write a uinput_user_dev structure to the device node. The change, and the reason for it, is described in the kernel checkin comment here:

torvalds/linux@052876f

After a change is made to the kernel source code, it takes time for it to find its way into various distributions. CentOS 6 was released in 2011. The version you're using, 6.10, must not have gotten this change.

There are two options for addressing this problem:

1. Upgrade to a newer version of CentOS that uses a newer kernel.
2. Modify the keyboard_mouse.c code to use the write() method of initializing the device outlined in the kernel checkin comment I linked to above.

Since I don't use a system with an old kernel that uses the old write() device initialization method, it's not very practical for me to try to do option 2 for you since I wouldn't be able to test and debug the alternate version.

I hope that helps.