Add v3_cons_sc sanity check for Terminal size

diff --git a/linux_usr/v3_cons_sc.c b/linux_usr/v3_cons_sc.c
index a8e7046..6d7e522 100644 (file)
--- a/linux_usr/v3_cons_sc.c
+++ b/linux_usr/v3_cons_sc.c
@@ -371,7 +371,32 @@ int send_char_to_palacios_as_scancodes(int fd, unsigned char c)
     }
     return 0;
 }
-    
+
+
+#define MIN_TTY_COLS  80
+#define MIN_TTY_ROWS  25
+int check_terminal_size (void)
+{
+    unsigned short n_cols = 0;
+    unsigned short n_rows = 0;
+    struct winsize winsz; 
+
+    ioctl (fileno(stdin), TIOCGWINSZ, &winsz);
+    n_cols = winsz.ws_col;
+    n_rows = winsz.ws_row;
+
+    if (n_cols < MIN_TTY_COLS || n_rows < MIN_TTY_ROWS) {
+        printf ("Your window is not large enough.\n");
+        printf ("It must be at least %dx%d, but yours is %dx%d\n",
+                MIN_TTY_COLS, MIN_TTY_ROWS, n_cols, n_rows);
+    return (-1);
+    }
+
+    /* SUCCESS */
+    return (0);
+}
+
+
 int main(int argc, char* argv[]) {
     int vm_fd;
     int cons_fd;
@@ -385,6 +410,12 @@ int main(int argc, char* argv[]) {
        return -1;
     }
 
+    /* Check for minimum Terminal size at start */
+    if (0 != check_terminal_size()) {
+        printf ("Error: terminal too small!\n");
+        return -1;
+    }
+
     vm_dev = argv[1];
 
     vm_fd = open(vm_dev, O_RDONLY);
@@ -450,13 +481,6 @@ int main(int argc, char* argv[]) {
 
     //ioctl(STDIN_FILENO, KDSKBMODE, K_RAW);
 
-    if (LINES<25 || COLS<80) { 
-       printf("Your window is not large enough.\nIt must be at least 80x25, but yours is %dx%d\n",COLS,LINES);
-       close(cons_fd);
-       exit(-1);
-    }
-    
-
     while (1) {
        int ret; 
        int bytes_read = 0;