Add a new ioctl to syscons, CONS_SCRSHOT. Given a userland buffer, it

copies out the current contents of the video buffer for a syscons terminal,
providing a snapshot of the text and attributes.

Based heavily on work originally submitted by Joel Holveck <joelh@gnu.org>
for 2.2.x almost 30 months ago, which I cleaned up a little, and forward
ported to -current.

See also the usr.bin/scrshot utility.

2 files changed, 28 insertions, 0 deletions

diff --git a/sys/dev/syscons/syscons.c b/sys/dev/syscons/syscons.c
index da11de9..f3305c4 100644
--- a/sys/dev/syscons/syscons.c
+++ b/sys/dev/syscons/syscons.c
@@ -838,6 +838,24 @@ scioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
 	splx(s);
 	return 0;
 
+    case CONS_SCRSHOT:		/* get a screen shot */
+    {
+	scrshot_t *ptr = (scrshot_t*)data;
+	s = spltty();
+	if (ISGRAPHSC(scp)) {
+	    splx(s);
+	    return EOPNOTSUPP;
+	}
+	if (scp->xsize != ptr->xsize || scp->ysize != ptr->ysize) {
+	    splx(s);
+	    return EINVAL;
+	}
+	copyout ((void*)scp->vtb.vtb_buffer, ptr->buf,
+		 ptr->xsize * ptr->ysize * sizeof(u_int16_t));
+	splx(s);
+	return 0;
+    }
+
     case VT_SETMODE:    	/* set screen switcher mode */
     {
 	struct vt_mode *mode;
diff --git a/sys/sys/consio.h b/sys/sys/consio.h
index 7a9fb02..5cb599a 100644
--- a/sys/sys/consio.h
+++ b/sys/sys/consio.h
@@ -239,6 +239,16 @@ typedef struct vid_info vid_info_t;
 /* release the current keyboard */
 #define CONS_RELKBD	_IO('c', 111)
 
+/* Snapshot the current video buffer */
+#define CONS_SCRSHOT	_IOWR('c', 105, scrshot_t)
+
+struct scrshot {
+	int		xsize;
+	int		ysize;
+	u_int16_t*	buf;
+};
+typedef struct scrshot scrshot_t;
+
 /* get/set the current terminal emulator info. */
 #define TI_NAME_LEN	32
 #define TI_DESC_LEN	64