[dev] [dvtm] ESC sequences in madtty.c

[Ross Mohn]

 Hi,

I'm no terminal expert, and I'm reluctant to add more code to the
madtty.c source, but I hope these changes will be considered. They
certainly work for me!

The existing ESC ] s (CUPSV) and ESC ] u (CUPRS) are for save/restore
cursor position. I use at least one program that uses ESC 7 (DECSC) and
ESC 8 (DECRC) to save/restore state, both cursor position and character
attributes, so I've implemented them. To do this, I created reusable
functions for save_curs(), restore_curs(), save_attrs(), and
restore_attrs() because they are used more than once now.

I also have some programs that were displaying weird reverse video
backgrounds, only in dvtm. To fix this I added code at the beginning and
end of the interpret_csi_ED() 'erase display' function so that the
display is always erased with A_NORMAL character attributes.

Thanks! --Ross


--- madtty000.c 2010-10-08 12:06:05.000000000 -0400
+++ madtty.c    2010-12-06 18:09:57.000000000 -0500
@@ -104,8 +105,8 @@
  
      /* geometry */
      int rows, cols, maxcols;
-     unsigned curattrs;
-     short curfg, curbg;
+     unsigned curattrs, scurattrs;
+     short curfg, curbg, scurfg, scurbg;
  
      /* scrollback buffer */
      struct t_row_t *scroll_buf;
@@ -229,6 +230,33 @@
      }
  }
  
+ static void save_curs(madtty_t *t)
+ {
+     t->curs_srow = t->curs_row - t->lines;
+     t->curs_scol = t->curs_col;
+ }
+ 
+ static void restore_curs(madtty_t *t)
+ {
+     t->curs_row = t->lines + t->curs_srow;
+     t->curs_col = t->curs_scol;
+     clamp_cursor_to_bounds(t);
+ }
+ 
+ static void save_attrs(madtty_t *t)
+ {
+     t->scurattrs = t->curattrs;
+     t->scurfg = t->curfg;
+     t->scurbg = t->curbg;
+ }
+ 
+ static void restore_attrs(madtty_t *t)
+ {
+     t->curattrs = t->scurattrs;
+     t->curfg = t->scurfg;
+     t->curbg = t->scurbg;
+ }
+ 
  static void clamp_cursor_to_bounds(madtty_t *t)
  {
      if (t->curs_row < t->lines) {
@@ -393,6 +421,10 @@
  {
      t_row_t *row, *start, *end;
  
+     save_attrs(t);
+     t->curattrs = A_NORMAL;
+     t->curfg = t->curbg = -1;
+ 
      /* decide range */
      if (pcount && param[0] == 2) {
          start = t->lines;
@@ -412,6 +444,8 @@
      for (row = start; row < end; row++) {
          t_row_set(row, 0, t->cols, t);
      }
+ 
+     restore_attrs(t);
  }
  
  /* interprets a 'move cursor' (CUP) escape sequence */
@@ -687,14 +721,9 @@
        case 'r': /* set scrolling region */
          interpret_csi_DECSTBM(t, csiparam, param_count); break;
        case 's': /* save cursor location */
-         t->curs_srow = t->curs_row - t->lines;
-         t->curs_scol = t->curs_col;
-         break;
+         save_curs(t); break;
        case 'u': /* restore cursor location */
-         t->curs_row = t->lines + t->curs_srow;
-         t->curs_col = t->curs_scol;
-         clamp_cursor_to_bounds(t);
-         break;
+         restore_curs(t); break;
        default:
          break;
      }
@@ -742,6 +771,18 @@
              return;
          }
          break;
+ 
+       case '7': /* save cursor and attrs */
+         save_attrs(t);
+         save_curs(t);
+         cancel_escape_sequence(t);
+         return;
+ 
+       case '8': /* restore cursor and attrs */
+         restore_attrs(t);
+         restore_curs(t);
+         cancel_escape_sequence(t);
+         return;
      }
  
      if (t->elen + 1 >= (int)sizeof(t->ebuf)) {
@@ -1224,7 +1265,7 @@
  
          maxfd = sysconf(_SC_OPEN_MAX);
          for (fd = 3; fd < maxfd; fd++)
-             if (close(fd) == EBADF)
+             if (close(fd) == -1 && errno == EBADF)
                  break;
  
          while (envp && envp[0]) {