Extend xdotool with getwindowstacklen command.

Makefile

@@ -49,7 +49,7 @@ CMDOBJS= cmd_click.o cmd_mousemove.o cmd_mousemove_relative.o cmd_mousedown.o \
          cmd_set_desktop_for_window.o cmd_get_desktop_for_window.o \
          cmd_get_desktop_viewport.o cmd_set_desktop_viewport.o \
          cmd_windowkill.o cmd_behave.o cmd_window_select.o \
-         cmd_getwindowname.o cmd_behave_screen_edge.o \
+         cmd_getwindowname.o cmd_getwindowstacklen.o cmd_behave_screen_edge.o \
          cmd_windowminimize.o cmd_exec.o cmd_getwindowgeometry.o \
          cmd_windowclose.o \
          cmd_sleep.o cmd_get_display_geometry.o

cmd_getwindowstacklen.c

@@ -0,0 +1,36 @@
+#include "xdo_cmd.h"
+
+int cmd_getwindowstacklen(context_t *context) {
+  char *cmd = context->argv[0];
+
+  int c;
+  static struct option longopts[] = {
+    { "help", no_argument, NULL, 'h' },
+    { 0, 0, 0, 0 },
+  };
+  static const char *usage = 
+    "Usage: %s \n"
+    HELP_SEE_WINDOW_STACK;
+  int option_index;
+
+  while ((c = getopt_long_only(context->argc, context->argv, "+h",
+                               longopts, &option_index)) != -1) {
+    switch (c) {
+      case 'h':
+        printf(usage, cmd);
+        consume_args(context, context->argc);
+        return EXIT_SUCCESS;
+        break;
+      default:
+        fprintf(stderr, usage, cmd);
+        return EXIT_FAILURE;
+    }
+  }
+
+
+  consume_args(context, optind);
+  xdotool_output(context, "stack_length:%i", context->nwindows);
+
+  return context->nwindows? EXIT_SUCCESS : EXIT_FAILURE;
+}
+

cmd_search.c

@@ -15,6 +15,7 @@ int cmd_search(context_t *context) {
   char out_prefix[17] = {'\0'};
   int search_class = 0;
   int search_classname = 0;
+  char flg_keep_chain = 0;
   typedef enum {
     opt_unused, opt_title, opt_onlyvisible, opt_name, opt_shell, opt_prefix, opt_class, opt_maxdepth,
     opt_pid, opt_help, opt_any, opt_all, opt_screen, opt_classname, opt_desktop,
@@ -139,6 +140,16 @@ int cmd_search(context_t *context) {
     }
   }
 
+  /*
+   * Look-ahead if next command can work with empty window stack or not.
+   */
+  if(context->argc > optind + 1){
+    if(*(context->argv + optind + 1)){
+      if(strcasecmp(*(context->argv + optind + 1), "getwindowstacklen") == 0){
+        flg_keep_chain = 1;
+      }
+    }
+  }
   consume_args(context, optind);
 
   /* We require a pattern or a pid to search for */
@@ -206,6 +217,10 @@ int cmd_search(context_t *context) {
   context->windows = list;
   context->nwindows = nwindows;
 
+  if(flg_keep_chain){
+    return EXIT_SUCCESS;
+  }
+
   /* error if number of windows found is zero (behave like grep) 
   but return success when being used inside eval (--shell option)*/
   return (nwindows || out_shell ? EXIT_SUCCESS : EXIT_FAILURE);

xdotool.c

@@ -225,6 +225,7 @@ struct dispatch {
   { "getwindowname", cmd_getwindowname, },
   { "getwindowpid", cmd_getwindowpid, },
   { "getwindowgeometry", cmd_getwindowgeometry, },
+  { "getwindowstacklen", cmd_getwindowstacklen, },
   { "getdisplaygeometry", cmd_get_display_geometry, },
   { "search", cmd_search, },
   { "selectwindow", cmd_window_select, },

xdotool.h

@@ -51,6 +51,7 @@ int cmd_getwindowfocus(context_t *context);
 int cmd_getwindowname(context_t *context);
 int cmd_getwindowpid(context_t *context);
 int cmd_getwindowgeometry(context_t *context);
+int cmd_getwindowstacklen(context_t *context);
 int cmd_help(context_t *context);
 int cmd_key(context_t *context);
 int cmd_mousedown(context_t *context);

xdotool.pod

@@ -539,6 +539,10 @@ Output values suitable for 'eval' in a shell.
 
 =back
 
+=item B<getwindowstacklen>
+
+Output the length of window stack. See L<WINDOW STACK> for more details.
+
 =item B<getwindowfocus> [-f]
 
 Prints the window id of the currently focused window. Saves the result to the