saconfig.c

Lua 语言解释器源码

/* sa-config.c -- configuration for stand-alone Lua interpreter
*
* #define LUA_USERCONFIG to this file
*
* Here are the features that can be customized using #define:
*
*** Line edit and history:
*   #define USE_READLINE to use the GNU readline library.
*
*   To use another library for this, use the code below as a start.
*   Make sure you #define lua_readline and lua_saveline accordingly.
*   If you do not #define lua_readline, you'll get a version based on fgets
*   that uses a static buffer of size MAXINPUT.
*
*
*** Static Lua libraries to be loaded at startup:
*   #define lua_userinit(L) to a Lua function that loads libraries; typically
*	#define lua_userinit(L)	openstdlibs(L);myinit(L)
*   or
*	#define lua_userinit(L)	myinit(L)
*
*   Another way is to add the prototypes of the init functions here and
*   #define LUA_EXTRALIBS accordingly. For example,
*	#define LUA_EXTRALIBS {"mylib","luaopen_mylib"},
*   Note the ending comma!
*
*
*** Prompts:
*   The stand-alone Lua interpreter uses two prompts: PROMPT and PROMPT2.
*   PROMPT is the primary prompt, shown when the intepreter is ready to receive
*   a new statement. PROMPT2 is the secondary prompt, shown while a statement
*   is being entered but is still incomplete.
*
*
*** Program name:
*   Error messages usually show argv[0] as a program name. In systems that do
*   not give a valid string as argv[0], error messages show PROGNAME instead.
*
*
*/

#ifdef USE_READLINE
/*
* This section implements of lua_readline and lua_saveline  for lua.c using
* the GNU readline and history libraries.  It should also work with drop-in
* replacements  such as  editline  and  libedit (you  may  have to  include
* different headers, though).
*
*/

#define lua_readline	myreadline
#define lua_saveline	mysaveline

#include <ctype.h>
#include <readline/readline.h>
#include <readline/history.h>

static int myreadline (lua_State *L, const char *prompt) {
  char *s=readline(prompt);
  if (s==NULL)
    return 0;
  else {
    lua_pushstring(L,s);
    lua_pushliteral(L,"\n");
    lua_concat(L,2);
    free(s);
    return 1;
  }
}

static void mysaveline (lua_State *L, const char *s) {
  const char *p;
  for (p=s; isspace(*p); p++)
    ;
  if (*p!=0) {
    size_t n=strlen(s)-1;
    if (s[n]!='\n')
      add_history(s);
    else {
      lua_pushlstring(L,s,n);
      s=lua_tostring(L,-1);
      add_history(s);
      lua_remove(L,-1);
    }
  }
}
#endif