lib/ss/get_readline.c

   1 /*
   2  * Copyright 2003 by MIT Student Information Processing Board
   3  *
   4  * Permission to use, copy, modify, and distribute this software and
   5  * its documentation for any purpose is hereby granted, provided that
   6  * the names of M.I.T. and the M.I.T. S.I.P.B. not be used in
   7  * advertising or publicity pertaining to distribution of the software
   8  * without specific, written prior permission.  M.I.T. and the
   9  * M.I.T. S.I.P.B. make no representations about the suitability of
  10  * this software for any purpose.  It is provided "as is" without
  11  * express or implied warranty.
  12  */
  13
  14 #ifdef HAS_STDLIB_H
  15 #include <stdlib.h>
  16 #endif
  17 #include "ss_internal.h"
  18 #define size    sizeof(ss_data *)
  19 #ifdef HAVE_DLOPEN
  20 #include <dlfcn.h>
  21 #endif
  22
  23 static void ss_release_readline(ss_data *info)
  24 {
  25 #ifdef HAVE_DLOPEN
  26         if (!info->readline_handle)
  27                 return;
  28
  29         info->readline = 0;
  30         info->add_history = 0;
  31         info->redisplay = 0;
  32         info->rl_completion_matches = 0;
  33         dlclose(info->readline_handle);
  34         info->readline_handle = 0;
  35 #endif
  36 }
  37
  38 void ss_get_readline(int sci_idx)
  39 {
  40 #ifdef HAVE_DLOPEN
  41         void    *handle;
  42         ss_data *info = ss_info(sci_idx);
  43         const char **t;
  44         char **(**completion_func)(const char *, int, int);
  45
  46         if (info->readline_handle ||
  47             getenv("SS_NO_READLINE") ||
  48             ((handle = dlopen("libreadline.so", RTLD_NOW)) == NULL))
  49                 return;
  50
  51         info->readline_handle = handle;
  52         info->readline = dlsym(handle, "readline");
  53         info->add_history = dlsym(handle, "add_history");
  54         info->redisplay = dlsym(handle, "rl_forced_update_display");
  55         info->rl_completion_matches = dlsym(handle, "rl_completion_matches");
  56         if ((t = dlsym(handle, "rl_readline_name")) != NULL)
  57                 *t = info->subsystem_name;
  58         if ((completion_func =
  59              dlsym(handle, "rl_attempted_completion_function")) != NULL)
  60                 *completion_func = ss_rl_completion;
  61         info->readline_shutdown = ss_release_readline;
  62 #endif
  63 }
  64
  65