Function sys_ftruncate 

pub fn sys_ftruncate(
    abi: &mut LinuxRiscv64Abi,
    trapframe: &mut Trapframe,
) -> usize

Linux sys_ftruncate implementation

Truncate a file to a specified length using a file descriptor.

Arguments:

• fd: File descriptor to truncate
• length: New file length

Returns:

• 0 on success
• negative errno on failure