next: https://viewsourcecode.org/snaptoken/kilo/04.aTextViewer.html#m…

…ove-to-the-end-of-the-line-with-end#status-message

kilo.c

@@ -51,6 +51,7 @@ struct editorConfig {
   int screencols;
   int numrows;
   erow *row;
+  char *filename;
   struct termios orig_termios;
 };
 
@@ -237,6 +238,9 @@ void editorAppendRow(char *s, size_t len) {
 /*** file i/o ***/
 
 void editorOpen(char *filename) {
+  free(E.filename);
+  E.filename = strdup(filename);
+
   FILE *fp = fopen(filename, "r");
   if (!fp) die("fopen");
 
@@ -408,16 +412,26 @@ void editorDrawRows(struct abuf *ab) {
     }
 
     abAppend(ab, "\x1b[K", 3);
-      abAppend(ab, "\r\n", 2);
+    abAppend(ab, "\r\n", 2);
   }
 }
 
 void editorDrawStatusBar(struct abuf *ab) {
   abAppend(ab, "\x1b[7m", 4);
-  int len = 0;
+  char status[80], rstatus[80];
+  int len = snprintf(status, sizeof(status), "%.20s - %d lines",
+                     E.filename ? E.filename : "[No Name]", E.numrows);
+  int rlen = snprintf(rstatus, sizeof(rstatus), "%d/%d", E.cy + 1, E.numrows);
+  if (len > E.screencols) len = E.screencols;
+  abAppend(ab, status, len);
   while (len < E.screencols) {
+    if (E.screencols - len == rlen) {
+      abAppend(ab, rstatus, rlen);
+      break;
+    } else {
       abAppend(ab, " ", 1);
       len++;
+    }
   }
   abAppend(ab, "\x1b[m", 3);
 }
@@ -453,6 +467,7 @@ void initEditor() {
   E.coloff = 0;
   E.numrows = 0;
   E.row = NULL;
+  E.filename = NULL;
 
   if (getWindowSize(&E.screenrows, &E.screencols) == -1) die("getWindowSize");
   E.screenrows -= 1;