shell: ^C cancels the line / aborts streams, ^D = EOF → poweroff

- ps2: Ctrl+C and Ctrl+D are now KeyEvents (ctrl modifier + c/d map);
  other Ctrl+key combos are swallowed
- shell read_line: ^C clears the line and echoes '^C' (bash-style),
  ^D on an empty line echoes '^D' and shuts down (EOF), ^D with text
  on the line is ignored
- cat/hexdump stream incrementally (was: build whole string then print)
  and check for ^C between chunks, so a running dump can be aborted
- verified in QEMU: line cancel, standalone interrupt, ^C aborts an
  infinite 'cat /dev/zero' stream, ^D powers off

1 files changed, 22 insertions, 10 deletions

diff --git a/rsnix/src/fs.rs b/rsnix/src/fs.rs
index 56820bb..95a84bf 100644
--- a/rsnix/src/fs.rs
+++ b/rsnix/src/fs.rs
@@ -15,14 +15,14 @@
 
 extern crate alloc;
 
-use alloc::boxed::Box;
-use alloc::string::String;
-use alloc::vec::Vec;
 use crate::gop;
 use crate::memory;
 use crate::pci;
 use crate::rtc;
 use crate::serial;
+use alloc::boxed::Box;
+use alloc::string::String;
+use alloc::vec::Vec;
 
 /// /dev/mem covers the low physical-memory window (identity-mapped RAM).
 pub const MEM_WINDOW: u64 = 64 * 1024;
@@ -96,9 +96,24 @@ pub fn init() -> (usize, usize) {
     let _tmp = add("tmp", Some(root), FileType::Dir, NodeData::Dir(Vec::new()));
     let etc = add("etc", Some(root), FileType::Dir, NodeData::Dir(Vec::new()));
 
-    add("mem", Some(dev), FileType::Char, NodeData::Char(CharDevice::Mem));
-    add("rtc", Some(dev), FileType::Char, NodeData::Char(CharDevice::Rtc));
-    add("pci", Some(dev), FileType::Char, NodeData::Char(CharDevice::Pci));
+    add(
+        "mem",
+        Some(dev),
+        FileType::Char,
+        NodeData::Char(CharDevice::Mem),
+    );
+    add(
+        "rtc",
+        Some(dev),
+        FileType::Char,
+        NodeData::Char(CharDevice::Rtc),
+    );
+    add(
+        "pci",
+        Some(dev),
+        FileType::Char,
+        NodeData::Char(CharDevice::Pci),
+    );
     add(
         "version",
         Some(dev),
@@ -146,10 +161,7 @@ pub fn init() -> (usize, usize) {
         ),
     );
 
-    let dirs = nodes()
-        .iter()
-        .filter(|n| n.kind == FileType::Dir)
-        .count();
+    let dirs = nodes().iter().filter(|n| n.kind == FileType::Dir).count();
     let files = nodes().len() - dirs;
     (dirs, files)
 }