Implemented stat syscall

examples/readfile/readfile.q

@@ -0,0 +1,13 @@
+import fs
+import sys
+
+main() {
+	show("/proc/sys/kernel/ostype")
+	show("/proc/sys/kernel/osrelease")
+	show("/proc/sys/kernel/arch")
+}
+
+show(path []byte) {
+	contents, length := fs.readFile(path)
+	sys.write(1, contents, length)
+}

lib/fs/fs.q

@@ -0,0 +1,27 @@
+import mem
+import sys
+
+readFile(path []byte) -> (*byte, int) {
+	stat := new(sys.file_stat)
+
+	if sys.stat(path, stat) < 0 {
+		return 0, 0
+	}
+
+	size := stat.st_size
+
+	if size < 512 {
+		size = 512
+	}
+
+	file := sys.open(path, 0, 0)
+
+	if file < 0 {
+		return 0, 0
+	}
+
+	contents := mem.alloc(size)
+	length := sys.read(file, contents, size)
+	sys.close(file)
+	return contents, length
+}

lib/sys/struct_linux.q

@@ -5,6 +5,29 @@ sockaddr_in {
 	sin_zero int64
 }
 
+file_stat {
+	st_dev uint64
+	st_ino uint64
+	st_nlink uint64
+	st_mode uint32
+	st_uid uint32
+	st_gid uint32
+	_ uint32
+	st_rdev uint64
+	st_size int64
+	st_blksize int64
+	st_blocks int64
+	st_atime int64
+	st_atime_nsec int64
+	st_mtime int64
+	st_mtime_nsec int64
+	st_ctime int64
+	st_ctime_nsec int64
+	_ int64
+	_ int64
+	_ int64
+}
+
 timespec {
 	seconds int64
 	nanoseconds int64

lib/sys/sys_linux.q

@@ -22,6 +22,10 @@ close(fd int) -> int {
 	return syscall(n.close, fd)
 }
 
+stat(path *any, stat *file_stat) -> int {
+	return syscall(n.newfstatat, -100, path, stat, 0)
+}
+
 clone(flags uint, stack *any, parent *int, child *int, tls uint) -> int {
 	return syscall(n.clone, flags, stack, parent, child, tls)
 }

lib/sys/sys_linux_arm.q

@@ -6,6 +6,7 @@ const {
 		munmap 215
 		openat 56
 		close 57
+		newfstatat 79
 		clone 220
 		execve 221
 		exit 93

lib/sys/sys_linux_x86.q

@@ -6,6 +6,7 @@ const {
 		munmap 11
 		openat 257
 		close 3
+		newfstatat 262
 		clone 56
 		execve 59
 		exit 60