Added support for readline-style Ctrl-v/Ctrl-q for literal char insert,

Ctrl-t transpose, and fixed weird chars to render as escape sequences.
Also changed redrawing code to not use saved cursor position and use
left movement instead.

ask.c

@@ -68,39 +68,56 @@ static int matches(const char *str, const char *patt)
     return 1;
 }
 
-static void draw_line(FILE *out, const char *line, const char *patt, int cursor, int stop_at_cursor)
+static int fputc_escaped(char c, FILE *out)
+{
+    static const char *escapes = "       abtnvfr             e";
+    if (c > 0 && c <= '\x1b' && escapes[(int)c] != ' ') { // "\n", etc.
+        fprintf(out, "\033[35m\\%c\033[37m", escapes[(int)c]);
+        return 2;
+    } else if (c >= 0 && !(' ' <= c && c <= '~')) { // "\x02", etc.
+        fprintf(out, "\033[35m\\x%02X\033[37m", c);
+        return 4;
+    } else {
+        fputc(c, out);
+        return 1;
+    }
+}
+
+static int draw_line(FILE *out, const char *line, const char *patt, int cursor)
 {
     size_t linelen = strlen(line), patlen = strlen(patt);
     int dim = 0;
     int p = 0;
     int run = 0;
     int *cache = calloc((linelen+1)*(patlen+1), sizeof(int));
-    if (patlen == 0 && stop_at_cursor)
+    int backtrack = 0;
-        return;
+    int to_start = 0;
     for (int i = 0; i < (int)linelen; i++) {
         if (EQ(patt[p], line[i]) &&
             run + lcs(line,patt,(int)linelen,(int)patlen,i,p,cache)
             >= lcs(line,patt,(int)linelen,(int)patlen,i+1,p,cache)) {
             if (dim) {
-                fputs("\033[22m", out);
+                fputs("\033[22;1m", out);
                 dim = 0;
             }
-            if (cursor == p && stop_at_cursor)
+            int len = fputc_escaped(line[i], out);
-                return;
+            if (p >= cursor) backtrack += len;
-            fputc(patt[p], out);
+            else to_start += len;
             ++run;
             ++p;
-            if (cursor == p && stop_at_cursor)
-                return;
         } else {
             run = 0;
             if (!dim) {
-                fputs("\033[2m", out);
+                fputs("\033[22;2m", out);
                 dim = 1;
             }
-            fputc(line[i], out);
+            int len = fputc_escaped(line[i], out);
+            if (p >= cursor) backtrack += len;
+            else to_start += len;
         }
     }
+    if (backtrack) fprintf(out, "\033[0m\033[%dD", backtrack);
+    return to_start;
 }
 
 /*
@@ -108,8 +125,8 @@ static void draw_line(FILE *out, const char *line, const char *patt, int cursor,
  */
 static char *get_input(FILE *in, FILE *out, const char *prompt, const char *initial, int nopts, char **opts)
 {
-    fputs("\0337", out);
     if (!prompt) prompt = "> ";
+    fprintf(out, "\033[K\033[0;1m%s\033[0m", prompt);
     size_t cap = initial ? strlen(initial) + 100 : 100;
     char *buf = memcheck(calloc(cap, 1));
     char *picked = NULL;
@@ -120,7 +137,7 @@ static char *get_input(FILE *in, FILE *out, const char *prompt, const char *init
         b = len;
     }
 
-    int start = 0;
+    int start = 0, backtrack = 0;
     while (1) {
         case_sensitive = 0;
         for (const char *p = buf; *p; ++p)
@@ -144,29 +161,20 @@ static char *get_input(FILE *in, FILE *out, const char *prompt, const char *init
         if (quickpick && ncandidates == 1 && picked)
             goto finished;
 
-        fprintf(out, "\0338\033[K\033[0;1m%s\033[0m", prompt);
+        if (backtrack) fprintf(out, "\033[%dD", backtrack);
+        fputs("\033[K", out);
         if (password) {
             if (picked) fputs("\033[0;32m", out);
             else if (nopts > 0) fputs("\033[0;31m", out);
             else fputs("\033[0;2m", out);
             fputc((PASSWORD)[strlen(buf) % strlen(PASSWORD)], out);
             fputs("\033[0m", out);
+            backtrack = 1;
         } else {
             if (picked) {
-                // Because stuff can have tabs and whatnot and the saved cusor
+                backtrack = draw_line(out, picked, buf, b);
-                // position is already in use, the most reliable way to make
-                // sure the cursor ends up in the right place is to draw the
-                // whole line, then redraw everything up to the cursor.
-                draw_line(out, picked, buf, b, 0);
-                fprintf(out, "\0338\033[0m\033[37;1m%s\033[0m", prompt);
-                draw_line(out, picked, buf, b, 1);
             } else {
-                if (nopts > 0)
+                backtrack = draw_line(out, buf, buf, b);
-                    fprintf(out, "\033[0;31m%s\033[0m", buf);
-                else
-                    fprintf(out, "\033[0m%s\033[0m", buf);
-                if (b < (int)strlen(buf))
-                    fprintf(out, "\033[%dD", (int)strlen(buf) - b);
             }
         }
         fflush(out);
@@ -184,10 +192,10 @@ static char *get_input(FILE *in, FILE *out, const char *prompt, const char *init
                 picked = NULL;
                 goto finished;
             case KEY_CTRL_A:
-                if (b > 0) b = 0;
+                b = 0;
                 break;
             case KEY_CTRL_E:
-                if (b < len) b = len;
+                b = len;
                 break;
             case KEY_CTRL_U: {
                 int to_clear = b;
@@ -243,8 +251,29 @@ static char *get_input(FILE *in, FILE *out, const char *prompt, const char *init
             case KEY_ARROW_RIGHT: case KEY_CTRL_F:
                 if (b < len) ++b;
                 break;
+            case KEY_CTRL_Q: case KEY_CTRL_V: {
+                int nextkey;
+                while ((nextkey = bgetkey(in, NULL, NULL, -1)) < 0)
+                    ;
+                if (len + 1 >= (int)cap)
+                    buf = memcheck(realloc(buf, (cap += 100)));
+                if (b < len)
+                    memmove(buf+b+1, buf+b, (size_t)(len-b+1));
+                buf[b++] = (char)nextkey;
+                buf[++len] = 0;
+                break;
+            }
+            case KEY_CTRL_T: {
+                if (len < 2 || b == 0) break;
+                if (b < len)
+                    b++;
+                char tmp = buf[b-1];
+                buf[b-1] = buf[b-2];
+                buf[b-2] = tmp;
+                break;
+            }
             default:
-                if (' ' <= key && key <= '~') {
+                if ((' ' <= key && key <= '~') || key == '\t') {
                     if (len + 1 >= (int)cap)
                         buf = memcheck(realloc(buf, (cap += 100)));
                     if (b < len)