Line-editing support in gdbmtool

* configure.ac: Check if GNU Readline is available.
* src/Makefile.am: Add new files.
* src/input-rl.c: New file.
* src/input-std.c: New file.
* src/gdbmtool.c (handler_param): Move declaration to
the header file.
(quit_handler): Call input_done.
(command_tab): Add the "history" command.
(command_generator): New function.
(slist_new_s, slist_new_l)
(slist_insert): New functions.
(main): Call input_init and input_done.
* src/gdbmtool.h: New protos.
* src/gram.y: Use slist_insert to construct string lists.
* src/lex.l (read_input): Remove.  Use input_read instead.
(print_prompt_at_bol): New function.
(print_prompt): Remove.
(make_prompt): New function.

* NEWS: Document changes.
* README: Document readline support.
* doc/gdbm.texi: Document line editing in gdbmtool.
* doc/gdbmtool.1: Likewise.

7 files changed, 483 insertions, 81 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 6a05634..b55deb6 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -79,7 +79,11 @@ libgdbmapp_a_SOURCES =\
 # Programs
 bin_PROGRAMS = gdbmtool gdbm_load gdbm_dump
 
-gdbmtool_LDADD  = ./libgdbmapp.a ./libgdbm.la
+gdbmtool_LDADD  = \
+ ./libgdbmapp.a\
+ ./libgdbm.la\
+ @READLINE_LIBS@
+
 gdbmtool_SOURCES = \
  datconv.c\
  gram.y\
@@ -89,6 +93,12 @@ gdbmtool_SOURCES = \
  var.c\
  util.c
 
+if GDBM_COND_READLINE
+  gdbmtool_SOURCES += input-rl.c
+else
+  gdbmtool_SOURCES += input-std.c
+endif
+
 AM_YFLAGS = -dtv
 #AM_LFLAGS = -d
 
diff --git a/src/gdbmtool.c b/src/gdbmtool.c
index 65b6740..2d57cbc 100644
--- a/src/gdbmtool.c
+++ b/src/gdbmtool.c
@@ -323,20 +323,6 @@ get_screen_lines ()
 #endif
   return -1;
 }
-
-
-#define ARG_UNUSED __attribute__ ((__unused__))
-
-#define NARGS 5
-
-struct handler_param
-{
-  int argc;
-  struct gdbmarg **argv;
-  FILE *fp;
-  void *data;
-};
-             
 
 /* Open database */
 void
@@ -751,7 +737,7 @@ quit_handler (struct handler_param *param ARG_UNUSED)
 {
   if (gdbm_file != NULL)
     gdbm_close (gdbm_file);
-
+  input_done ();
   exit (EXIT_OK);
 }
 
@@ -891,6 +877,8 @@ struct argdef
   int ds;
 };
 
+#define NARGS 5
+
 struct command
 {
   char *name;           /* Command name */
@@ -902,7 +890,6 @@ struct command
   struct argdef args[NARGS];
   char *doc;
 };
-
 
 struct command command_tab[] = {
 #define S(s) #s, sizeof (#s) - 1
@@ -1007,6 +994,13 @@ struct command command_tab[] = {
     NULL, open_handler, NULL,
     { { "FILE", GDBM_ARG_STRING }, { NULL } },
     N_("open new database") },
+#ifdef WITH_READLINE
+  { S(history), T_CMD,
+    input_history_begin, input_history_handler, NULL,
+    { { N_("[FROM]"), GDBM_ARG_STRING },
+      { N_("[COUNT]"), GDBM_ARG_STRING },
+      { NULL } }, N_("show input history") },
+#endif
 #undef S
   { 0 }
 };
@@ -1026,6 +1020,39 @@ sort_commands ()
          sizeof (command_tab[0]), cmdcmp);
 }
 
+/* Generator function for command completion.  STATE lets us know whether
+   to start from scratch; without any state (i.e. STATE == 0), then we
+   start at the top of the list. */
+char *
+command_generator (const char *text, int state)
+{
+  const char *name;
+  static int len;
+  static struct command *cmd;
+
+  /* If this is a new word to complete, initialize now.  This includes
+     saving the length of TEXT for efficiency, and initializing the index
+     variable to 0. */
+  if (!state)
+    {
+      cmd = command_tab;
+      len = strlen (text);
+    }
+
+  if (!cmd->name)
+    return NULL;
+
+  /* Return the next name which partially matches from the command list. */
+  while ((name = cmd->name))
+    {
+      cmd++;
+      if (strncmp (name, text, len) == 0)
+        return strdup (name);
+    }
+
+  /* If no names matched, then return NULL. */
+  return NULL;
+}
 
 /* ? - help handler */
 #define CMDCOLS 30
@@ -1174,7 +1201,7 @@ gdbmarg_kvpair (struct kvpair *kvp, struct locus *loc)
 }
 
 struct slist *
-slist_new (char *s)
+slist_new_s (char *s)
 {
   struct slist *lp = emalloc (sizeof (*lp));
   lp->next = NULL;
@@ -1182,6 +1209,21 @@ slist_new (char *s)
   return lp;
 }
 
+struct slist *
+slist_new (char const *s)
+{
+  return slist_new_s (estrdup (s));
+}
+
+struct slist *
+slist_new_l (char const *s, size_t l)
+{
+  char *copy = emalloc (l + 1);
+  memcpy (copy, s, l);
+  copy[l] = 0;
+  return slist_new_s (copy);
+}
+
 void
 slist_free (struct slist *lp)
 {
@@ -1193,6 +1235,21 @@ slist_free (struct slist *lp)
       lp = next;
     }
 }
+
+void
+slist_insert (struct slist **where, struct slist *what)
+{
+  if (*where)
+    {
+      while (what->next)
+        what = what->next;
+      what->next = (*where)->next;
+      (*where)->next = what;
+    }
+  else
+    what->next = NULL;
+  *where = what;
+}
 
 struct kvpair *
 kvpair_string (struct locus *loc, char *val)
@@ -1216,7 +1273,6 @@ kvpair_list (struct locus *loc, struct slist *s)
   return p;
 }  
 
-
 static void
 kvlist_free (struct kvpair *kvp)
 {
@@ -1534,6 +1590,7 @@ main (int argc, char *argv[])
   int opt;
   int bv;
   int norc = 0;
+  int res;
   char *source = "-";
   
   set_progname (argv[0]);
@@ -1545,15 +1602,18 @@ main (int argc, char *argv[])
   textdomain (PACKAGE);
 
   sort_commands ();
-
+  
   /* Initialize variables. */
   intr = isatty (0);
+  interactive = intr; /* Used early by input_init */
   dsdef[DS_KEY] = dsegm_new_field (datadef_lookup ("string"), NULL, 1);