4 files changed, 39 insertions, 14 deletions

diff --git a/src/user/app/shell.c b/src/user/app/shell.c
index 3a08af4..952b9b7 100644
--- a/src/user/app/shell.c
+++ b/src/user/app/shell.c
@@ -46,21 +46,24 @@ static void cmd_cat_ls(const char *args, bool ls) {
 	static char buf[512];
 	int len; // first used for strlen(args), then length of buffer
 
-	if (!args) args = "/";
-	len = strlen(args);
-	memcpy(buf, args, len + 1); // no overflow check - the shell is just a PoC
-
-	if (ls) { // paths to directories always have a trailing slash
-		char *p = buf;
-		while (*p) p++;
-		if (p[-1] != '/') {
-			p[0] = '/';
-			p[1] = '\0';
-			len++;
+	if (args) {
+		len = strlen(args);
+		memcpy(buf, args, len + 1); // no overflow check - the shell is just a PoC
+
+		if (ls) { // paths to directories always have a trailing slash
+			if (buf[len-1] != '/') {
+				buf[len] = '/';
+				buf[len+1] = '\0';
+			}
 		}
+
+		file = file_open(buf, 0);
+	} else if (ls) { /* ls default argument */
+		file = file_open("/", 0);
+	} else { /* cat default argument */
+		file = file_clone(stdin);
 	}
 
-	file = file_open(buf, 0);
 	if (!file) {
 		printf("couldn't open.\n");
 		return;
diff --git a/src/user/driver/termcook.c b/src/user/driver/termcook.c
index 6ed8223..56ac77c 100644
--- a/src/user/driver/termcook.c
+++ b/src/user/driver/termcook.c
@@ -28,8 +28,12 @@ static void line_editor(handle_t input, handle_t output) {
 					}
 					break;
 				case 4: /* EOT, C-d */
-					w_output(output, linebuf, linepos);
-					linepos = 0;
+					if (linepos > 0) {
+						w_output(output, linebuf, linepos);
+						linepos = 0;
+					} else {
+						_syscall_write(output, NULL, 0, 0); // eof
+					}
 					break;
 				case '\n':
 				case '\r':
diff --git a/src/user/lib/stdlib.c b/src/user/lib/stdlib.c
index 32b4f06..56b8bb4 100644
--- a/src/user/lib/stdlib.c
+++ b/src/user/lib/stdlib.c
@@ -94,6 +94,23 @@ fail:
 	return NULL;
 }
 
+libc_file *file_clone(const libc_file *f) {
+	handle_t h = _syscall_dup(f->fd, -1, 0);
+	libc_file *f2;
+	if (h < 0) return NULL;
+
+	// TODO file_wrapfd
+	f2 = malloc(sizeof *f2);
+	if (!f2) {
+		close(h);
+		return NULL;
+	}
+	f2->pos = f->pos;
+	f2->eof = f->eof;
+	f2->fd = h;
+	return f2;
+}
+
 int file_read(libc_file *f, char *buf, size_t len) {
 	if (f->fd < 0) return -1;
 
diff --git a/src/user/lib/stdlib.h b/src/user/lib/stdlib.h
index 22227e3..1982e85 100644
--- a/src/user/lib/stdlib.h
+++ b/src/user/lib/stdlib.h
@@ -17,6 +17,7 @@ typedef struct {
 } libc_file;
 libc_file *file_open(const char *path, int flags);
 libc_file *file_reopen(libc_file*, const char *path, int flags);
+libc_file *file_clone(const libc_file*);
 int file_read(libc_file*, char *buf, size_t len);
 int file_write(libc_file*, const char *buf, size_t len);
 void file_close(libc_file*);