Support the DECSCUSR CSI escape sequence

st.c

@@ -197,14 +197,14 @@ typedef struct {
 } TCursor;
 
 /* CSI Escape sequence structs */
-/* ESC '[' [[ [<priv>] <arg> [;]] <mode>] */
+/* ESC '[' [[ [<priv>] <arg> [;]] <mode> [<mode>]] */
 typedef struct {
 	char buf[ESC_BUF_SIZ]; /* raw string */
 	int len;               /* raw string length */
 	char priv;
 	int arg[ESC_ARG_SIZ];
 	int narg;              /* nb of args */
-	char mode;
+	char mode[2];
 } CSIEscape;
 
 /* STR Escape sequence structs */
@@ -257,6 +257,7 @@ typedef struct {
 	int ch; /* char height */
 	int cw; /* char width  */
 	char state; /* focus, redraw, visible */
+	int cursor; /* cursor style */
 } XWindow;
 
 typedef struct {
@@ -1545,7 +1546,8 @@ csiparse(void) {
 			break;
 		p++;
 	}
-	csiescseq.mode = *p;
+	csiescseq.mode[0] = *p++;
+	csiescseq.mode[1] = (p < csiescseq.buf+csiescseq.len) ? *p : '\0';
 }
 
 /* for absolute user moves, when decom is set */
@@ -1983,7 +1985,7 @@ csihandle(void) {
 	char buf[40];
 	int len;
 
-	switch(csiescseq.mode) {
+	switch(csiescseq.mode[0]) {
 	default:
 	unknown:
 		fprintf(stderr, "erresc: unknown csi ");
@@ -2171,6 +2173,19 @@ csihandle(void) {
 	case 'u': /* DECRC -- Restore cursor position (ANSI.SYS) */
 		tcursor(CURSOR_LOAD);
 		break;
+	case ' ':
+		switch (csiescseq.mode[1]) {
+			case 'q': /* DECSCUSR -- Set Cursor Style */
+				DEFAULT(csiescseq.arg[0], 1);
+				if (!BETWEEN(csiescseq.arg[0], 0, 6)) {
+					goto unknown;
+				}
+				xw.cursor = csiescseq.arg[0];
+				break;
+			default:
+				goto unknown;
+		}
+		break;
 	}
 }
 
@@ -3551,16 +3566,36 @@ xdrawcursor(void) {
 
 	/* draw the new one */
 	if(xw.state & WIN_FOCUSED) {
-		if(IS_SET(MODE_REVERSE)) {
-			g.mode |= ATTR_REVERSE;
-			g.fg = defaultcs;
-			g.bg = defaultfg;
-		}
+		switch (xw.cursor) {
+			case 0: /* Blinking Block */
+			case 1: /* Blinking Block (Default) */
+			case 2: /* Steady Block */
+				if(IS_SET(MODE_REVERSE)) {
+						g.mode |= ATTR_REVERSE;
+						g.fg = defaultcs;
+						g.bg = defaultfg;
+					}
 
-		sl = utf8len(g.c);
-		width = (term.line[term.c.y][curx].mode & ATTR_WIDE)\
-			? 2 : 1;
-		xdraws(g.c, g, term.c.x, term.c.y, width, sl);
+				sl = utf8len(g.c);
+				width = (term.line[term.c.y][curx].mode & ATTR_WIDE)\
+					? 2 : 1;
+				xdraws(g.c, g, term.c.x, term.c.y, width, sl);
+				break;
+			case 3: /* Blinking Underline */
+			case 4: /* Steady Underline */
+				XftDrawRect(xw.draw, &dc.col[defaultcs],
+						borderpx + curx * xw.cw,
+						borderpx + (term.c.y + 1) * xw.ch - 1,
+						xw.cw, 1);
+				break;
+			case 5: /* Blinking bar */
+			case 6: /* Steady bar */
+				XftDrawRect(xw.draw, &dc.col[defaultcs],
+								borderpx + curx * xw.cw,
+								borderpx + term.c.y * xw.ch,
+								1, xw.ch);
+				break;
+		}
 	} else {
 		XftDrawRect(xw.draw, &dc.col[defaultcs],
 				borderpx + curx * xw.cw,
@@ -3985,6 +4020,7 @@ main(int argc, char *argv[]) {
 
 	xw.l = xw.t = 0;
 	xw.isfixed = False;
+	xw.cursor = 0;
 
 	ARGBEGIN {
 	case 'a':