readline/NSH: Extend the tab-completion logic so that NSH commands can also be completed by pressing the tab key

ChangeLog.txt

@@ -1368,3 +1368,6 @@
 	* apps/system/readline:  Add support for Unix-style tab complete toi
 	  readline.  This currently works only for built-in functions.i
 	  Contributed by Nghia (2015-07-28).
+	* apps/system/readline and apps/nshlib:  Extended the tab-completion
+	  support to also expand NSH command names (2015-07-30).
+

include/readline.h

@@ -47,6 +47,27 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
+#ifndef CONFIG_READLINE_MAX_BUILTINS
+#  define CONFIG_READLINE_MAX_BUILTINS 64
+#endif
+
+#ifndef CONFIG_READLINE_MAX_EXTCMDS
+#  define CONFIG_READLINE_MAX_EXTCMDS 64
+#endif
+
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+#if defined(CONFIG_READLINE_TABCOMPLETION) && defined(CONFIG_READLINE_HAVE_EXTMATCH)
+struct extmatch_vtable_s
+{
+  CODE int (*count_matches)(FAR char *name, FAR int *matches, int namelen);
+  CODE FAR const char *(*getname)(int index);
+};
+#endif
+
 /****************************************************************************
  * Public Data
  ****************************************************************************/
@@ -72,10 +93,11 @@ extern "C"
  *   to reprint the prompt string.
  *
  * Input Parameters:
- *   prompt    - The prompt string.
+ *   prompt    - The prompt string. This function may then be
+ *   called with that value in order to restore the previous vtable.
  *
  * Returned values:
- *   None
+ *   Returns the previous value of the prompt string
  *
  * Assumptions:
  *   The prompt string is statically allocated a global.  readline will
@@ -87,11 +109,40 @@ extern "C"
  **************************************************************************/
 
 #ifdef CONFIG_READLINE_TABCOMPLETION
-void readline_prompt(FAR const char *prompt);
+FAR const char *readline_prompt(FAR const char *prompt);
 #else
 #  define readline_prompt(p)
 #endif
 
+/****************************************************************************
+ * Name: readline_extmatch
+ *
+ *   If the applications supports a command set, then it may call this
+ *   function in order to provide support for tab complete on these\
+ *   "external"  commands
+ *
+ * Input Parameters:
+ *   vtbl - Callbacks to access the external names.
+ *
+ * Returned values:
+ *   Returns the previous vtable pointer.  This function may then be
+ *   called with that value in order to restore the previous vtable.
+ *
+ * Assumptions:
+ *   The vtbl string is statically allocated a global.  readline will
+ *   simply remember the pointer to the structure.  The structure must stay
+ *   allocated and available.  Only one instance of such a structure is 
+ *   upported.  If there are multiple clients of readline, they must all
+ *   share the same tab-completion logic (with exceptions in the case of
+ *   the kernel build).
+ *
+ **************************************************************************/
+
+#if defined(CONFIG_READLINE_TABCOMPLETION) && defined(CONFIG_READLINE_HAVE_EXTMATCH)
+FAR const struct extmatch_vtable_s *
+  readline_extmatch(FAR const struct extmatch_vtable_s *vtbl);
+#endif
+
 /****************************************************************************
  * Name: readline
  *

nshlib/Kconfig

@@ -8,6 +8,7 @@ config NSH_LIBRARY
 	default n
 	select NETUTILS_NETLIB if NET
 	select LIBC_NETDB if NET
+	select READLINE_HAVE_EXTMATCH
 	---help---
 		Build the NSH support library.  This is used, for example, by
 		examples/nsh in order to implement the full NuttShell (NSH).

nshlib/nsh.h

@@ -1055,4 +1055,49 @@ void nsh_usbtrace(void);
 #  endif
 #endif
 
+/****************************************************************************
+ * Name: nsh_extmatch_count
+ *
+ * Description:
+ *   This support function is used to provide support for realine tab-
+ *   completion logic  nsh_extmatch_count() counts the number of matching
+ *   nsh command names
+ *
+ * Input Parameters:
+ *   name    - A point to the name containing the name to be matched.
+ *   matches - A table is size CONFIG_READLINE_MAX_EXTCMDS that can
+ *             be used to remember matching name indices.
+ *   namelen - The lenght of the name to match
+ *
+ * Returned Values:
+ *   The number commands that match to the first namelen characters.
+ *
+ ****************************************************************************/
+
+#if defined(CONFIG_NSH_READLINE) && defined(CONFIG_READLINE_TABCOMPLETION) && \
+    defined(CONFIG_READLINE_HAVE_EXTMATCH)
+int nsh_extmatch_count(FAR char *name, FAR int *matches, int namelen);
+#endif
+
+/****************************************************************************
+ * Name: nsh_extmatch_getname
+ *
+ * Description:
+ *   This support function is used to provide support for realine tab-
+ *   completion logic  nsh_extmatch_getname() will return the full command
+ *   string from an index that was previously saved by nsh_exmatch_count().
+ *
+ * Input Parameters:
+ *   index - The index of the command name to be returned.
+ *
+ * Returned Values:
+ *   The numb
+ *
+ ****************************************************************************/
+
+#if defined(CONFIG_NSH_READLINE) && defined(CONFIG_READLINE_TABCOMPLETION) && \
+    defined(CONFIG_READLINE_HAVE_EXTMATCH)
+FAR const char *nsh_extmatch_getname(int index);
+#endif
+
 #endif /* __APPS_NSHLIB_NSH_H */

nshlib/nsh_command.c

@@ -45,6 +45,10 @@
 #  include <nuttx/binfmt/builtin.h>
 #endif
 
+#if defined(CONFIG_SYSTEM_READLINE) && defined(CONFIG_READLINE_HAVE_EXTMATCH)
+#  include <apps/readline.h>
+#endif
+
 #include "nsh.h"
 #include "nsh_console.h"
 
@@ -824,3 +828,73 @@ int nsh_command(FAR struct nsh_vtbl_s *vtbl, int argc, char *argv[])
    ret = handler(vtbl, argc, argv);
    return ret;
 }
+
+/****************************************************************************
+ * Name: nsh_extmatch_count
+ *
+ * Description:
+ *   This support function is used to provide support for realine tab-
+ *   completion logic  nsh_extmatch_count() counts the number of matching
+ *   nsh command names
+ *
+ * Input Parameters:
+ *   name    - A point to the name containing the name to be matched.
+ *   matches - A table is size CONFIG_READLINE_MAX_EXTCMDS that can
+ *             be used to remember matching name indices.
+ *   namelen - The lenght of the name to match
+ *
+ * Returned Values:
+ *   The number commands that match to the first namelen characters.
+ *
+ ****************************************************************************/
+
+#if defined(CONFIG_NSH_READLINE) && defined(CONFIG_READLINE_TABCOMPLETION) && \
+    defined(CONFIG_READLINE_HAVE_EXTMATCH)
+int nsh_extmatch_count(FAR char *name, FAR int *matches, int namelen)
+{
+  int nr_matches = 0;
+  int i;
+
+  for (i = 0; i < NUM_CMDS; i++)
+    {
+      if (strncmp(name, g_cmdmap[i].cmd, namelen) == 0)
+        {
+          matches[nr_matches] = i;
+          nr_matches++;
+
+          if (nr_matches >= CONFIG_READLINE_MAX_EXTCMDS)
+            {
+              break;
+            }
+        }
+    }
+
+  return nr_matches;
+}
+#endif
+
+/****************************************************************************
+ * Name: nsh_extmatch_getname
+ *
+ * Description:
+ *   This support function is used to provide support for realine tab-
+ *   completion logic  nsh_extmatch_getname() will return the full command
+ *   string from an index that was previously saved by nsh_exmatch_count().
+ *
+ * Input Parameters:
+ *   index - The index of the command name to be returned.
+ *
+ * Returned Values:
+ *   The numb
+ *
+ ****************************************************************************/
+
+#if defined(CONFIG_NSH_READLINE) && defined(CONFIG_READLINE_TABCOMPLETION) && \
+    defined(CONFIG_READLINE_HAVE_EXTMATCH)
+FAR const char *nsh_extmatch_getname(int index)
+{
+  DEBUGASSERT(index > 0 && index <= NUM_CMDS);
+  return  g_cmdmap[index].cmd;
+}
+#endif
+

nshlib/nsh_init.c

@@ -40,6 +40,7 @@
 #include <nuttx/config.h>
 
 #include <sys/boardctl.h>
+
 #include <apps/readline.h>
 #include <apps/nsh.h>
 
@@ -61,7 +62,16 @@
  * Private Data
  ****************************************************************************/
 
-/****************************************************************************
+#if defined(CONFIG_NSH_READLINE) && defined(CONFIG_READLINE_TABCOMPLETION) && \
+    defined(CONFIG_READLINE_HAVE_EXTMATCH)
+static const struct extmatch_vtable_s g_nsh_extmatch =
+{
+  nsh_extmatch_count,  /* count_matches */
+  nsh_extmatch_getname /* getname */
+};
+#endif
+
+  /**************************************************************************
  * Public Data
  ****************************************************************************/
 
@@ -105,9 +115,15 @@ void nsh_initialize(void)
 
   (void)nsh_netinit();
 
-#ifdef CONFIG_READLINE_TABCOMPLETION
+#if defined(CONFIG_NSH_READLINE) && defined(CONFIG_READLINE_TABCOMPLETION)
   /* Configure the NSH prompt */
 
-  readline_prompt(g_nshprompt);
+  (void)readline_prompt(g_nshprompt);
+
+#ifdef CONFIG_READLINE_HAVE_EXTMATCH
+  /* Set up for tab completion on NSH commands */
+
+  (void)readline_extmatch(&g_nsh_extmatch);
+#endif
 #endif
 }

system/readline/Kconfig

@@ -9,6 +9,10 @@ menuconfig SYSTEM_READLINE
 	---help---
 		Enable support for the readline() function.
 
+config READLINE_HAVE_EXTMATCH
+	bool
+	default n
+
 if SYSTEM_READLINE
 
 config READLINE_ECHO
@@ -23,9 +27,28 @@ config READLINE_ECHO
 config READLINE_TABCOMPLETION
 	bool "Tab completion"
 	default n
-	depends on BUILD_FLAT && BUILTIN
+	depends on (BUILD_FLAT && BUILTIN) || READLINE_HAVE_EXTMATCH
 	---help---
 		Build in support for Unix-style tab completion.  This feature was
-		provided by Nghia.
+		originally provided by Nghia.
 
-endif
+if READLINE_TABCOMPLETION
+
+config READLINE_MAX_BUILTINS
+	int "Maximum built-in matches"
+	default 64
+    depends on BUILTIN
+	---help---
+		This the maximum number of matching names of builtin commands that
+		will be displayed.
+
+config READLINE_MAX_EXTCMDS
+    int "Maximum built-in matches"
+    default 64
+    depends on READLINE_HAVE_EXTMATCH
+    ---help---
+        This the maximum number of matching names of builtin commands that
+        will be displayed.
+
+endif # READLINE_TABCOMPLETION
+endif # SYSTEM_READLINE

system/readline/readline_common.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * apps/system/readline/readline_common.c
  *
- *   Copyright (C) 2007-2008, 2011-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2008, 2011-2013, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -64,12 +64,56 @@ static const char g_erasetoeol[] = VT100_CLEAREOL;
 /* Prompt string to present at the beginning of the line */
 
 static FAR const char *g_readline_prompt = NULL;
+
+#ifdef CONFIG_READLINE_HAVE_EXTMATCH
+static FAR const struct extmatch_vtable_s *g_extmatch_vtbl = NULL;
+#endif
 #endif
 
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
 
+/****************************************************************************
+ * Name: count_builtin_maches
+ *
+ * Description:
+ *   Count the number of builtin commands
+ *
+ * Input Parameters:
+ *   matches - Array to save builtin command index.
+ *   len - The length of the matching name to try
+ *
+ * Returned Value:
+ *   The number of matching names
+ *
+ **************************************************************************/
+
+#if defined(CONFIG_READLINE_TABCOMPLETION) && defined(CONFIG_BUILTIN)
+static int count_builtin_maches(FAR char *buf, FAR int *matches, int namelen)
+{
+  FAR const char *name;
+  int nr_matches = 0;
+  int i;
+
+  for (i = 0; (name = builtin_getname(i)) != NULL; i++)
+    {
+      if (strncmp(buf, name, namelen) == 0)
+        {
+          matches[nr_matches] = i;
+          nr_matches++;
+
+          if (nr_matches >= CONFIG_READLINE_MAX_BUILTINS)
+            {
+              break;
+            }
+        }
+    }
+
+  return nr_matches;
+}
+#endif
+
 /****************************************************************************
  * Name: tab_completion
  *
@@ -87,36 +131,83 @@ static FAR const char *g_readline_prompt = NULL;
  **************************************************************************/
 
 #ifdef CONFIG_READLINE_TABCOMPLETION
-void tab_completion(FAR struct rl_common_s *vtbl, char *buf, int *nch)
+static void tab_completion(FAR struct rl_common_s *vtbl, char *buf,
+                           int *nch)
 {
   FAR const char *name = NULL;
-  int num_matches = 0;
+#ifdef CONFIG_BUILTIN
-  int matches[128];
+  int nr_builtin_matches = 0;
+  int builtin_matches[CONFIG_READLINE_MAX_BUILTINS];
+#endif
+#ifdef CONFIG_BUILTIN
+  int nr_ext_matches = 0;
+  int ext_matches[CONFIG_READLINE_MAX_EXTCMDS];
+#endif
+  int nr_matches;
   int len = *nch;
   int i;
   int j;
 
   if (len >= 1)
     {
-      for (i = 0; (name = builtin_getname(i)) != NULL; i++)
+#ifdef CONFIG_BUILTIN
-        {
+      /* Count the matching builtin commands */
-          if (!strncmp(buf, name, len))
-            {
-              matches[num_matches] = i;
-              num_matches++;
 
-              if (num_matches >= sizeof(matches) / sizeof(int))
+      nr_builtin_matches = count_builtin_maches(buf, builtin_matches, len);
+      nr_matches         = nr_builtin_matches;
+#else
+      nr_matches         = 0;
+#endif
+
+#ifdef CONFIG_READLINE_HAVE_EXTMATCH
+      /* Is there registered external handling logic? */
+
+      nr_ext_matches     = 0;
+      if (g_extmatch_vtbl != NULL)
         {
-                  break;
+          /* Count the number of external commands */
-                }
+
-            }
+          nr_ext_matches = g_extmatch_vtbl->count_matches(buf, ext_matches, len);
+          nr_matches    += nr_ext_matches;
         }
 
-      if (num_matches ==  1)
+#endif
-        {
-          name = builtin_getname(matches[0]);
 
-          int name_len = strlen(name);
+      /* Is there only one matching name? */
+
+      if (nr_matches ==  1)
+        {
+          int name_len;
+
+          /* Yes... that that is the one we want.  Was it a match with a
+           * builtin command?  Or with an external command.
+           */
+
+#ifdef CONFIG_BUILTIN
+#ifdef CONFIG_READLINE_HAVE_EXTMATCH
+          if (nr_builtin_matches ==  1)
+#endif
+            {
+              /* It is a match with a builtin command */
+
+              name = builtin_getname(builtin_matches[0]);
+            }
+#endif
+
+#ifdef CONFIG_READLINE_HAVE_EXTMATCH
+#ifdef CONFIG_BUILTIN
+          else
+#endif
+            {
+              /* It is a match with an external command */
+
+              name = g_extmatch_vtbl->getname(ext_matches[0]);
+            }
+#endif
+
+          /* Copy the name to the command buffer and to the display. */
+
+          name_len = strlen(name);
 
           for (j = len; j < name_len; j++)
             {
@@ -124,22 +215,26 @@ void tab_completion(FAR struct rl_common_s *vtbl, char *buf, int *nch)
               RL_PUTC(vtbl, name[j]);
             }
 
-          /* Don't remove extra characters after the completed word, if any */
+          /* Don't remove extra characters after the completed word, if any. */
 
           if (len < name_len)
             {
               *nch = name_len;
             }
         }
-      else if (num_matches > 1)
+
+      /* Are there multiple matching names? */
+
+      else if (nr_matches > 1)
         {
           RL_PUTC(vtbl, '\n');
 
-          /* possible completion */
+#ifdef CONFIG_READLINE_HAVE_EXTMATCH
+          /* Show the possible external completions */
 
-          for (i = 0; i < num_matches; i++)
+          for (i = 0; i < nr_ext_matches; i++)
             {
-              name = builtin_getname(matches[i]);
+              name = g_extmatch_vtbl->getname(ext_matches[i]);
 
               RL_PUTC(vtbl, ' ');
               RL_PUTC(vtbl, ' ');
@@ -151,6 +246,26 @@ void tab_completion(FAR struct rl_common_s *vtbl, char *buf, int *nch)
 
               RL_PUTC(vtbl, '\n');
             }
+#endif
+
+#ifdef CONFIG_BUILTIN
+          /* Show the possible builtin completions */
+
+          for (i = 0; i < nr_builtin_matches; i++)
+            {
+              name = builtin_getname(builtin_matches[i]);
+
+              RL_PUTC(vtbl, ' ');
+              RL_PUTC(vtbl, ' ');
+
+              for (j = 0; j < strlen(name); j++)
+                {
+                  RL_PUTC(vtbl, name[j]);
+                }
+
+              RL_PUTC(vtbl, '\n');
+            }
+#endif
 
           /* Output the original prompt */
 
@@ -184,10 +299,11 @@ void tab_completion(FAR struct rl_common_s *vtbl, char *buf, int *nch)
  *   to reprint the prompt string.
  *
  * Input Parameters:
- *   prompt    - The prompt string.
+ *   prompt    - The prompt string. This function may then be
+ *   called with that value in order to restore the previous vtable.
  *
  * Returned values:
- *   None
+ *   Returns the previous value of the prompt string
  *
  * Assumptions:
  *   The prompt string is statically allocated a global.  readline will
@@ -199,9 +315,45 @@ void tab_completion(FAR struct rl_common_s *vtbl, char *buf, int *nch)
  **************************************************************************/
 
 #ifdef CONFIG_READLINE_TABCOMPLETION
-void readline_prompt(FAR const char *prompt)
+FAR const char *readline_prompt(FAR const char *prompt)
 {
+  FAR const char *ret = g_readline_prompt;
   g_readline_prompt = prompt;
+  return ret;
+}
+#endif
+
+/****************************************************************************
+ * Name: readline_extmatch
+ *
+ *   If the applications supports a command set, then it may call this
+ *   function in order to provide support for tab complete on these\
+ *   "external"  commands
+ *
+ * Input Parameters:
+ *   vtbl - Callbacks to access the external names.
+ *
+ * Returned values:
+ *   Returns the previous vtable pointer.  This function may then be
+ *   called with that value in order to restore the previous vtable.
+ *
+ * Assumptions:
+ *   The vtbl string is statically allocated a global.  readline will
+ *   simply remember the pointer to the structure.  The structure must stay
+ *   allocated and available.  Only one instance of such a structure is 
+ *   upported.  If there are multiple clients of readline, they must all
+ *   share the same tab-completion logic (with exceptions in the case of
+ *   the kernel build).
+ *
+ **************************************************************************/
+
+#if defined(CONFIG_READLINE_TABCOMPLETION) && defined(CONFIG_READLINE_HAVE_EXTMATCH)
+FAR const struct extmatch_vtable_s *
+  readline_extmatch(FAR const struct extmatch_vtable_s *vtbl)
+{
+  FAR const struct extmatch_vtable_s *ret = g_extmatch_vtbl;
+  g_extmatch_vtbl = vtbl;
+  return ret;
 }
 #endif