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.

1 files changed, 80 insertions, 54 deletions

diff --git a/src/lex.l b/src/lex.l
index 9c2c5f8..236474d 100644
--- a/src/lex.l
+++ b/src/lex.l
@@ -43,24 +43,22 @@ advance_line ()
   while (0);
 
 #undef YY_INPUT
 #define YY_INPUT(buf,result,max_size)                                   \
   do                                                                    \
     {                                                                   \
-      result = read_input (buf, max_size);                              \
+      result = input_read (yyin, buf, max_size);                        \
     }                                                                   \
   while (0);
  
 void string_begin (void);
 void string_add (const char *s, int l);
 void string_addc (int c);
 char *string_end (void);
 int unescape (int c);
 
-static ssize_t read_input (char *buf, size_t size);
-
 struct context                /* Input context */
 {
   struct context *parent;     /* Pointer to the parent context */
   struct locus locus;         /* Locus */
   struct point point;
   int interactive;
@@ -312,24 +310,22 @@ begin_def (void)
 void
 end_def (void)
 {
   BEGIN (INITIAL);
 } 
 
-static ssize_t
-read_input (char *buf, size_t size)
+void
+print_prompt_at_bol (void)
 {
-  if (interactive)
+  if (YY_AT_BOL ())
     {
-      if (YY_AT_BOL ())
-        print_prompt ();
-      if (fgets (buf, size, yyin) == NULL)
-        return 0;
-      return strlen (buf);
+      char *s = make_prompt ();
+      fputs (s, stdout);
+      fflush (stdout);
+      free (s);
     }
-  return fread (buf, 1, size, yyin);
 }
   
 
 struct strseg
 {
   struct strseg *next;
@@ -450,121 +446,151 @@ lerror (struct locus *loc, const char *fmt, ...)
   va_start (ap, fmt);
   vlerror (loc, fmt, ap);
   va_end (ap);
 }
 
 
-struct prompt_exp;
-
-void
-pe_file_name (struct prompt_exp *p)
+static struct slist *
+pe_file_name (void)
 {
-  if (file_name)
-    fwrite (file_name, strlen (file_name), 1, stdout);
+  return file_name ? slist_new (file_name) : NULL;
 }
 
-void
-pe_program_name (struct prompt_exp *p)
+static struct slist *
+pe_program_name (void)
 {
-  fwrite (progname, strlen (progname), 1, stdout);
+  return slist_new (progname);
 }
 
-void
-pe_package_name (struct prompt_exp *p)
+static struct slist *
+pe_package_name (void)
 {
-  fwrite (PACKAGE_NAME, sizeof (PACKAGE_NAME) - 1, 1, stdout);
+  return slist_new (PACKAGE_NAME);
 }
 
-void
-pe_program_version (struct prompt_exp *p)
+static struct slist *
+pe_program_version (void)
 {
-  fwrite (PACKAGE_VERSION, sizeof (PACKAGE_VERSION) - 1, 1, stdout);
+  return slist_new (PACKAGE_VERSION);
 }
 
-void
-pe_space (struct prompt_exp *p)
+static struct slist *
+pe_space (void)
 {
-  fwrite (" ", 1, 1, stdout);
+  return slist_new (" ");
 }
 
 struct prompt_exp
 {
   int ch;
-  void (*fun) (struct prompt_exp *);
-  char *cache;
+  struct slist *(*fun) (void);
 };
 
 struct prompt_exp prompt_exp[] = {
   { 'f', pe_file_name },
   { 'p', pe_program_name },
   { 'P', pe_package_name },
   { 'v', pe_program_version },
   { '_', pe_space },
   { 0 }
 };
 
-static void
-expand_char (int c)
+static int
+expand_char (int c, struct slist **tailp)
 {
   struct prompt_exp *p;
 
   if (c && c != '%')
     {
       for (p = prompt_exp; p->ch; p++)
         {
           if (c == p->ch)
             {
-              if (p->cache)
-                free (p->cache);
-              p->fun (p);
-              return;
+              struct slist *s = p->fun ();
+              if (s)
+                slist_insert (tailp, s);
+              return 0;
             }
         }
     }
-  putchar ('%');
-  putchar (c);
+  return 1;
 }
 
 char const *
-psname ()
+psname (void)
 {
   if (YYSTATE == DEF || YYSTATE == MLSTR)
     return "ps2";
   return "ps1";
 }
 
-void
-print_prompt ()
+char *
+make_prompt (void)
 {
   const char *s;
   const char *prompt;
-
+  struct slist *head = NULL, *tail = NULL, *p;
+  char *ret, *end;
+  size_t len;
+  
   switch (variable_get (psname (), VART_STRING, (void *) &prompt))
     {
     case VAR_OK:
       break;
 
     case VAR_ERR_NOTSET:
-      return;
+      return NULL;
       
     default:
       abort ();
     }
-  
-  for (s = prompt; *s; s++)
+
+  for (s = prompt; *s; )
     {
-      if (*s == '%')
+      if (*s == '%' && s[1])
         {
-          if (!*++s)
+          if (s > prompt)
+            {
+              slist_insert (&tail, slist_new_l (prompt, s - prompt));
+              if (!head)
+                head = tail;
+            }
+          if (expand_char (s[1], &tail) == 0)