@PcodeUserop
	@EmuSyscall("close")
	public T unix_close(T fd) {
		PcodeArithmetic<T> arithmetic = machine.getArithmetic();
		int ifd = (int) arithmetic.toLong(fd, Purpose.OTHER);
		// TODO: Some fs.close or file.close, when all handles have released it?
		EmuUnixFileDescriptor<T> desc = releaseFd(ifd);
		desc.close();
		return arithmetic.fromConst(0, intSize);
	}
The UNIX {@code close} system call

@param fd the file descriptor
@return 0 for success
Ghidra/Features/SystemEmulation/src/main/java/ghidra/pcode/emu/unix/AbstractEmuUnixSyscallUseropLibrary.java