diff --git a/src/libvterm/bin/vterm-ctrl.c b/src/libvterm/bin/vterm-ctrl.c
new file mode 100644
index 0000000..14e35cd
--- /dev/null
+++ b/src/libvterm/bin/vterm-ctrl.c
@@ -0,0 +1,362 @@
+#define _XOPEN_SOURCE 500  /* strdup */
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#define streq(a,b) (strcmp(a,b)==0)
+
+#include <termios.h>
+
+static char *getvalue(int *argip, int argc, char *argv[])
+{
+  if(*argip >= argc) {
+    fprintf(stderr, "Expected an option value\n");
+    exit(1);
+  }
+
+  return argv[(*argip)++];
+}
+
+static int getchoice(int *argip, int argc, char *argv[], const char *options[])
+{
+  const char *arg = getvalue(argip, argc, argv);
+
+  int value = -1;
+  while(options[++value])
+    if(streq(arg, options[value]))
+      return value;
+
+  fprintf(stderr, "Unrecognised option value %s\n", arg);
+  exit(1);
+}
+
+typedef enum {
+  OFF,
+  ON,
+  QUERY
+} BoolQuery;
+
+static BoolQuery getboolq(int *argip, int argc, char *argv[])
+{
+  const char *choices[] = {"off", "on", "query", NULL};
+  return getchoice(argip, argc, argv, choices);
+}
+
+static char *helptext[] = {
+  "reset",
+  "s8c1t [off|on]",
+  "keypad [app|num]",
+  "screen [off|on|query]",
+  "cursor [off|on|query]",
+  "curblink [off|on|query]",
+  "curshape [block|under|bar|query]",
+  "mouse [off|click|clickdrag|motion]",
+  "altscreen [off|on|query]",
+  "bracketpaste [off|on|query]",
+  "icontitle [STR]",
+  "icon [STR]",
+  "title [STR]",
+  NULL
+};
+
+static bool seticanon(bool icanon, bool echo)
+{
+  struct termios termios;
+
+  tcgetattr(0, &termios);
+
+  bool ret = (termios.c_lflag & ICANON);
+
+  if(icanon) termios.c_lflag |=  ICANON;
+  else       termios.c_lflag &= ~ICANON;
+
+  if(echo) termios.c_lflag |=  ECHO;
+  else     termios.c_lflag &= ~ECHO;
+
+  tcsetattr(0, TCSANOW, &termios);
+
+  return ret;
+}
+
+static void await_c1(int c1)
+{
+  int c;
+
+  /* await CSI - 8bit or 2byte 7bit form */
+  bool in_esc = false;
+  while((c = getchar())) {
+    if(c == c1)
+      break;
+    if(in_esc && c == (char)(c1 - 0x40))
+      break;
+    if(!in_esc && c == 0x1b)
+      in_esc = true;
+    else
+      in_esc = false;
+  }
+}
+
+static char *read_csi()
+{
+  unsigned char csi[32];
+  int i = 0;
+
+  await_c1(0x9B); /* CSI */
+
+  /* TODO: This really should be a more robust CSI parser
+   */
+  for(; i < sizeof(csi)-1; i++) {
+    int c = csi[i] = getchar();
+    if(c >= 0x40 && c <= 0x7e)
+      break;
+  }
+  csi[++i] = 0;
+
+  /* TODO: returns longer than 32? */
+
+  return strdup((char *)csi);
+}
+
+static char *read_dcs()
+{
+  unsigned char dcs[32];
+  bool in_esc = false;
+  int i;
+
+  await_c1(0x90);
+
+  for(i = 0; i < sizeof(dcs)-1; ) {
+    char c = getchar();
+    if(c == 0x9c) /* ST */
+      break;
+    if(in_esc && c == 0x5c)
+      break;
+    if(!in_esc && c == 0x1b)
+      in_esc = true;
+    else {
+      dcs[i++] = c;
+      in_esc = false;
+    }
+  }
+  dcs[++i] = 0;
+
+  return strdup((char *)dcs);
+}
+
+static void usage(int exitcode)
+{
+  char **p;
+
+  fprintf(stderr, "Control a libvterm-based terminal\n"
+      "\n"
+      "Options:\n");
+
+  for(p = helptext; *p; p++)
+    fprintf(stderr, "  %s\n", *p);
+
+  exit(exitcode);
+}
+
+static bool query_dec_mode(int mode)
+{
+  char *s = NULL;
+
+  printf("\x1b[?%d$p", mode);
+
+  do {
+    int reply_mode, reply_value;
+    char reply_cmd;
+
+    if(s)
+      free(s);
+    s = read_csi();
+
+    /* expect "?" mode ";" value "$y" */
+
+    /* If the sscanf format string ends in a literal, we can't tell from
+     * its return value if it matches. Hence we'll %c the cmd and check it
+     * explicitly
+     */
+    if(sscanf(s, "?%d;%d$%c", &reply_mode, &reply_value, &reply_cmd) < 3)
+      continue;
+    if(reply_cmd != 'y')
+      continue;
+
+    if(reply_mode != mode)
+      continue;
+
+    free(s);
+
+    if(reply_value == 1 || reply_value == 3)
+      return true;
+    if(reply_value == 2 || reply_value == 4)
+      return false;
+
+    printf("Unrecognised reply to DECRQM: %d\n", reply_value);
+    return false;
+  } while(1);
+}
+
+static void do_dec_mode(int mode, BoolQuery val, const char *name)
+{
+  switch(val) {
+    case OFF:
+    case ON:
+      printf("\x1b[?%d%c", mode, val == ON ? 'h' : 'l');
+      break;
+
+    case QUERY:
+      if(query_dec_mode(mode))
+        printf("%s on\n", name);
+      else
+        printf("%s off\n", name);
+      break;
+  }
+}
+
+static int query_rqss_numeric(char *cmd)
+{
+  char *s = NULL;
+
+  printf("\x1bP$q%s\x1b\\", cmd);
+
+  do {
+    int num;
+
+    if(s)
+      free(s);
+    s = read_dcs();
+
+    if(!s)
+      return -1;
+    if(strlen(s) < strlen(cmd))
+      return -1;
+    if(strcmp(s + strlen(s) - strlen(cmd), cmd) != 0) {
+      printf("No match\n");
+      continue;
+    }
+
+    if(s[0] != '1' || s[1] != '$' || s[2] != 'r')
+      return -1;
+
+    if(sscanf(s + 3, "%d", &num) != 1)
+      return -1;
+
+    return num;
+  } while(1);
+}
+
+bool wasicanon;
+
+void restoreicanon(void)
+{
+  seticanon(wasicanon, true);
+}
+
+int main(int argc, char *argv[])
+{
+  int argi = 1;
+
+  if(argc == 1)
+    usage(0);
+
+  wasicanon = seticanon(false, false);
+  atexit(restoreicanon);
+
+  while(argi < argc) {
+    const char *arg = argv[argi++];
+
+    if(streq(arg, "reset")) {
+      printf("\x1b" "c");
+    }
+    else if(streq(arg, "s8c1t")) {
+      const char *choices[] = {"off", "on", NULL};
+      switch(getchoice(&argi, argc, argv, choices)) {
+      case 0:
+        printf("\x1b F"); break;
+      case 1:
+        printf("\x1b G"); break;
+      }
+    }
+    else if(streq(arg, "keypad")) {
+      const char *choices[] = {"app", "num", NULL};
+      switch(getchoice(&argi, argc, argv, choices)) {
+      case 0:
+        printf("\x1b="); break;
+      case 1:
+        printf("\x1b>"); break;
+      }
+    }
+    else if(streq(arg, "screen")) {
+      do_dec_mode(5, getboolq(&argi, argc, argv), "screen");
+    }
+    else if(streq(arg, "cursor")) {
+      do_dec_mode(25, getboolq(&argi, argc, argv), "cursor");
+    }
+    else if(streq(arg, "curblink")) {
+      do_dec_mode(12, getboolq(&argi, argc, argv), "curblink");
+    }
+    else if(streq(arg, "curshape")) {
+      /* TODO: This ought to query the current value of DECSCUSR because it */
+      /*   may need blinking on or off */
+      const char *choices[] = {"block", "under", "bar", "query", NULL};
+      int shape = getchoice(&argi, argc, argv, choices);
+      switch(shape) {
+        case 3: /* query */
+          shape = query_rqss_numeric(" q");
+          switch(shape) {
+            case 1: case 2:
+              printf("curshape block\n");
+              break;
+            case 3: case 4:
+              printf("curshape under\n");
+              break;
+            case 5: case 6:
+              printf("curshape bar\n");
+              break;
+          }
+          break;
+
+        case 0:
+        case 1:
+        case 2:
+          printf("\x1b[%d q", 1 + (shape * 2));
+          break;
+      }
+    }
+    else if(streq(arg, "mouse")) {
+      const char *choices[] = {"off", "click", "clickdrag", "motion", NULL};
+      switch(getchoice(&argi, argc, argv, choices)) {
+      case 0:
+        printf("\x1b[?1000l"); break;
+      case 1:
+        printf("\x1b[?1000h"); break;
+      case 2:
+        printf("\x1b[?1002h"); break;
+      case 3:
+        printf("\x1b[?1003h"); break;
+      }
+    }
+    else if(streq(arg, "altscreen")) {
+      do_dec_mode(1049, getboolq(&argi, argc, argv), "altscreen");
+    }
+    else if(streq(arg, "bracketpaste")) {
+      do_dec_mode(2004, getboolq(&argi, argc, argv), "bracketpaste");
+    }
+    else if(streq(arg, "icontitle")) {
+      printf("\x1b]0;%s\a", getvalue(&argi, argc, argv));
+    }
+    else if(streq(arg, "icon")) {
+      printf("\x1b]1;%s\a", getvalue(&argi, argc, argv));
+    }
+    else if(streq(arg, "title")) {
+      printf("\x1b]2;%s\a", getvalue(&argi, argc, argv));
+    }
+    else {
+      fprintf(stderr, "Unrecognised command %s\n", arg);
+      exit(1);
+    }
+  }
+  return 0;
+}