src/user/info.nsc

include "syscalls.nsh";
include "stdio.nsh";
 
void
print_stat(ptr label, u64 val)
{
	puts(label);
	put_udec(val);
	putchar((u8)10);
}
 
/* prints a virtual file's content straight through -- /int/mem and
 * /int/cpu (virtfs.nsc, kernel-side) already format themselves as
 * plain readable text, so "info" showing memory/cpu sections is
 * nothing more than opening and reading them, the same way ps.nsc is
 * just a hardcoded cat of /proc/ps. */
void
cat_virtfile(ptr path, u64 path_len)
{
	i8 buf[256];
	i32 fd;
	i64 n;
 
	fd = sys_open(path, path_len);
	if(fd < 0)
	{
		return;
	}
	n = sys_read(fd, &buf[0], (u64)256);
	if(n > (i64)0)
	{
		sys_write(1, &buf[0], (u64)n);
	}
	sys_close(fd);
}
 
/* dumps kfs stats (blocks/inodes), then memory and cpu info by way of
 * /int/mem and /int/cpu -- no options, matching the rest of this
 * kernel's coreutils; extend the info(buf) syscall (idt.nsc's number
 * 14) if kfs ever needs its own new numbers here instead. */
global i32
main(i32 argc, ptr argv)
{
	u64 stats[4];
 
	sys_info((ptr)&stats[0]);
	print_stat("blocks total: ", stats[0]);
	print_stat("blocks used:  ", stats[1]);
	print_stat("inodes total: ", stats[2]);
	print_stat("inodes used:  ", stats[3]);
	stdio_flush();
 
	cat_virtfile("/int/mem", (u64)8);
	cat_virtfile("/int/cpu", (u64)8);
	return 0;
}