readline-related functions.

+/* GNU mailutils - a suite of utilities for electronic mail
+   Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include "mail.h"
+
+static char **ml_command_completion __P((char *cmd, int start, int end));
+static char *ml_command_generator __P((char *text, int state));
+
+static int _interrupt;
+
+static RETSIGTYPE
+sig_int(int signo)
+{
+  if (util_find_env("quit")->set)
+    exit (0);
+  _interrupt++;
+  signal (signo, sig_int);
+}
+
+void
+ml_clear_interrupt()
+{
+  _interrupt = 0;
+}
+
+int
+ml_got_interrupt()
+{
+  int rc = _interrupt;
+  _interrupt = 0;
+  return rc;
+}
+
+#ifdef WITH_READLINE
+int
+ml_getc (FILE *stream)
+{
+    unsigned char c;
+
+    if (read (fileno (stream), &c, 1) == 1)
+      return c;
+    return EOF;
+}
+#endif
+
+void
+ml_readline_init ()
+{
+  if (!interactive)
+    return;
+  
+#ifdef WITH_READLINE
+  rl_readline_name = "mail";
+  rl_attempted_completion_function = (CPPFunction*)ml_command_completion;
+  rl_getc_function = ml_getc;
+#endif
+  signal(SIGINT, sig_int);
+}
+
+#ifdef WITH_READLINE
+
+static char *insert_text;
+
+static int
+ml_insert_hook()
+{
+  if (insert_text)
+    rl_insert_text(insert_text);
+  return 0;
+}
+
+int
+ml_reread(char *prompt, char **text)
+{
+  char *s;
+  
+  insert_text = *text;
+  rl_startup_hook = ml_insert_hook;
+  s = readline(prompt);
+  if (*text)
+    free(*text);
+  *text = s;
+  rl_startup_hook = NULL;
+  return 0;
+}
+
+/*
+ * readline tab completion
+ */
+char **
+ml_command_completion (char *cmd, int start, int end)
+{
+  if (start == 0)
+    return completion_matches (cmd, ml_command_generator);
+  return NULL;
+}
+
+/*
+ * more readline
+ */
+char *
+ml_command_generator (char *text, int state)
+{
+  static int i, len;
+  char *name;
+
+  if (!state)
+    {
+      i = 0;
+      len = strlen (text);
+    }
+
+  while ((name = mail_command_table[i].longname))
+    {
+      if (strlen (mail_command_table[i].shortname) > strlen(name))
+	name = mail_command_table[i].shortname;
+      i++;
+      if (strncmp (name, text, len) == 0)
+	return (strdup(name));
+    }
+
+  return NULL;
+}
+
+#else
+
+int
+ml_reread(char *prompt, char **text)
+{
+  char *s;
+  /*FIXME*/
+  s = readline(prompt);
+  if (*text)
+    free(*text);
+  *text = s;
+  return 0;
+}
+
+char *
+readline (const char *prompt)
+{
+  char *line;
+  char *p;
+  size_t alloclen, linelen;
+
+  if (prompt)
+    {
+      fprintf (ofile, "%s", prompt);
+      fflush (ofile);
+    }
+
+  p = line = calloc (1, 255);
+  alloclen = 255;
+  linelen = 0;
+  for (;;)
+    {
+      size_t n;
+
+      p = fgets (p, alloclen - linelen, stdin);
+      
+      if (p)
+	n = strlen(p);
+      else if (_interrupt)
+	{
+	  free (line);
+	  return NULL;
+	}
+      else
+	n = 0;
+
+      linelen += n;
+
+      /* Error.  */
+      if (linelen == 0)
+	{
+	  free (line);
+	  return NULL;
+	}
+
+      /* Ok.  */
+      if (line[linelen - 1] == '\n')
+	{
+	  line[linelen - 1] = '\0';
+	  return line;
+	}
+      else
+        {
+	  char *tmp;
+	  alloclen *= 2;
+	  tmp = realloc (line, alloclen);
+	  if (tmp == NULL)
+	    {
+	      free (line);
+	      return NULL;
+	    }
+	  line = tmp;
+	  p = line + linelen;
+	}
+    }
+}
+#endif
+