liolib.c

小游戏 linux very happy

/*
** $Id: liolib.c,v 1.6 2003/06/30 19:15:26 ahowe Exp $
** Standard I/O (and system) library
** This file modified from it's original form.
** See Copyright Notice in lua.h
*/


#include <ctype.h>
#include <stdio.h>
#define __USE_MISC /* for mkstemp() */
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <assert.h>

#ifndef macintosh
#ifndef WIN32
#  include <unistd.h> /* for close() */
#endif
#endif

#ifdef WIN32
#  define close _close
#endif

#include "lua.h"

#include "lauxlib.h"
#include "luadebug.h"
#include "lualib.h"


#ifndef OLD_ANSI
#include <errno.h>
#include <locale.h>
#define realloc(b,s)    ((b) == NULL ? malloc(s) : (realloc)(b, s))
#define free(b)         if (b) (free)(b)
#else
/* no support for locale and for strerror: fake them */
#define setlocale(a,b)	((void)a, strcmp((b),"C")==0?"C":NULL)
#define LC_ALL		0
#define LC_COLLATE	0
#define LC_CTYPE	0
#define LC_MONETARY	0
#define LC_NUMERIC	0
#define LC_TIME		0
#define strerror(e)	"generic I/O error"
#define errno		(-1)
#endif



#ifdef POPEN
/* FILE *popen();
int pclose(); */
#define CLOSEFILE(L, f)    ((pclose(f) == -1) ? fclose(f) : 0)
#else
/* no support for popen */
#define popen(x,y) NULL  /* that is, popen always fails */
#define CLOSEFILE(L, f)    (fclose(f))
#endif


#define INFILE	0
#define OUTFILE 1

typedef struct IOCtrl {
  int ref[2];  /* ref for strings _INPUT/_OUTPUT */
  int iotag;    /* tag for file handles */
  int closedtag;  /* tag for closed handles */
} IOCtrl;



static const char *const filenames[] = {"_INPUT", "_OUTPUT"};


static int pushresult (lua_State *L, int i) {
  if (i) {
    lua_pushuserdata(L, NULL);
    return 1;
  }
  else {
    lua_pushnil(L);
    lua_pushstring(L, strerror(errno));
    lua_pushnumber(L, errno);
    return 3;;
  }
}


/*
** {======================================================
** FILE Operations
** =======================================================
*/


static FILE *gethandle (lua_State *L, IOCtrl *ctrl, int f) {
  void *p = lua_touserdata(L, f);
  if (p != NULL) {  /* is `f' a userdata ? */
    int ftag = lua_tag(L, f);
    if (ftag == ctrl->iotag)  /* does it have the correct tag? */
      return (FILE *)p;
    else if (ftag == ctrl->closedtag)
      lua_error(L, "cannot access a closed file");
    /* else go through */
  }
  return NULL;
}


static FILE *getnonullfile (lua_State *L, IOCtrl *ctrl, int arg) {
  FILE *f = gethandle(L, ctrl, arg);
  luaL_arg_check(L, f, arg, "invalid file handle");
  return f;
}


static FILE *getfilebyref (lua_State *L, IOCtrl *ctrl, int inout) {
  FILE *f;
  lua_getglobals(L);
  lua_getref(L, ctrl->ref[inout]);
  lua_rawget(L, -2);
  f = gethandle(L, ctrl, -1);
  if (f == NULL)
    luaL_verror(L, "global variable `%.10s' is not a file handle",
                filenames[inout]);
  return f;
}


static void setfilebyname (lua_State *L, IOCtrl *ctrl, FILE *f,
                           const char *name) {
  lua_pushusertag(L, f, ctrl->iotag);
  lua_setglobal(L, name);
}


#define setfile(L,ctrl,f,inout)	(setfilebyname(L,ctrl,f,filenames[inout]))


static int setreturn (lua_State *L, IOCtrl *ctrl, FILE *f, int inout) {
  if (f == NULL)
    return pushresult(L, 0);
  else {
    setfile(L, ctrl, f, inout);
    lua_pushusertag(L, f, ctrl->iotag);
    return 1;
  }
}


static int closefile (lua_State *L, IOCtrl *ctrl, FILE *f) {
  if (f == stdin || f == stdout || f == stderr)
    return 1;
  else {
    lua_pushusertag(L, f, ctrl->iotag);
    lua_settag(L, ctrl->closedtag);
    return (CLOSEFILE(L, f) == 0);
  }
}


static int io_close (lua_State *L) {
  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
  lua_pop(L, 1);  /* remove upvalue */
  return pushresult(L, closefile(L, ctrl, getnonullfile(L, ctrl, 1)));
}


static int file_collect (lua_State *L) {
  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
  FILE *f = getnonullfile(L, ctrl, 1);
  if (f != stdin && f != stdout && f != stderr)
    CLOSEFILE(L, f);
  return 0;
}


static int io_open (lua_State *L) {
  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
  FILE *f;
  lua_pop(L, 1);  /* remove upvalue */
  f = fopen(luaL_check_string(L, 1), luaL_check_string(L, 2));
  if (f) {
    lua_pushusertag(L, f, ctrl->iotag);
    return 1;
  }
  else
    return pushresult(L, 0);
}



static int io_fromto (lua_State *L, int inout, const char *mode) {
  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
  FILE *current;
  lua_pop(L, 1);  /* remove upvalue */
  if (lua_isnull(L, 1)) {
    closefile(L, ctrl, getfilebyref(L, ctrl, inout));
    current = (inout == 0) ? stdin : stdout;    
  }
  else if (lua_tag(L, 1) == ctrl->iotag)  /* deprecated option */
    current = (FILE *)lua_touserdata(L, 1);
  else {
    const char *s = luaL_check_string(L, 1);
    current = (*s == '|') ? popen(s+1, mode) : fopen(s, mode);
  }
  return setreturn(L, ctrl, current, inout);
}


static int io_readfrom (lua_State *L) {
  return io_fromto(L, INFILE, "r");
}


static int io_writeto (lua_State *L) {
  return io_fromto(L, OUTFILE, "w");
}


static int io_appendto (lua_State *L) {
  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
  FILE *current;
  lua_pop(L, 1);  /* remove upvalue */
  current = fopen(luaL_check_string(L, 1), "a");
  return setreturn(L, ctrl, current, OUTFILE);
}



/*
** {======================================================
** READ
** =======================================================
*/



#ifdef LUA_COMPAT_READPATTERN

/*
** We cannot lookahead without need, because this can lock stdin.
** This flag signals when we need to read a next char.
*/
#define NEED_OTHER (EOF-1)  /* just some flag different from EOF */


static int read_pattern (lua_State *L, FILE *f, const char *p) {
  int inskip = 0;  /* {skip} level */
  int c = NEED_OTHER;
  luaL_Buffer b;
  luaL_buffinit(L, &b);
  while (*p != '\0') {
    switch (*p) {
      case '{':
        inskip++;
        p++;
        continue;
      case '}':
        if (!inskip) lua_error(L, "unbalanced braces in read pattern");
        inskip--;
        p++;
        continue;
      default: {
        const char *ep = luaI_classend(L, p);  /* get what is next */
        int m;  /* match result */
        if (c == NEED_OTHER) c = getc(f);
        m = (c==EOF) ? 0 : luaI_singlematch(c, p, ep);
        if (m) {
          if (!inskip) luaL_putchar(&b, c);
          c = NEED_OTHER;
        }
        switch (*ep) {
          case '+':  /* repetition (1 or more) */
            if (!m) goto break_while;  /* pattern fails? */
            /* else go through */
          case '*':  /* repetition (0 or more) */
            while (m) {  /* reads the same item until it fails */
              c = getc(f);
              m = (c==EOF) ? 0 : luaI_singlematch(c, p, ep);
              if (m && !inskip) luaL_putchar(&b, c);
            }
            /* go through to continue reading the pattern */
          case '?':  /* optional */
            p = ep+1;  /* continues reading the pattern */
            continue;
          default:
            if (!m) goto break_while;  /* pattern fails? */
            p = ep;  /* else continues reading the pattern */
        }
      }
    }
  } break_while:
  if (c != NEED_OTHER) ungetc(c, f);
  luaL_pushresult(&b);  /* close buffer */
  return (*p == '\0');
}

#else

#define read_pattern(L, f, p) (lua_error(L, "read patterns are deprecated"), 0)

#endif


static int read_number (lua_State *L, FILE *f) {
  double d;
  if (fscanf(f, "%lf", &d) == 1) {
    lua_pushnumber(L, d);
    return 1;
  }
  else return 0;  /* read fails */
}


static int read_word (lua_State *L, FILE *f) {
  int c;
  luaL_Buffer b;
  luaL_buffinit(L, &b);
  do { c = fgetc(f); } while (isspace(c));  /* skip spaces */
  while (c != EOF && !isspace(c)) {
    luaL_putchar(&b, c);
    c = fgetc(f);
  }
  ungetc(c, f);
  luaL_pushresult(&b);  /* close buffer */
  return (lua_strlen(L, -1) > 0);
}


static int read_line (lua_State *L, FILE *f) {
  int n = 0;
  luaL_Buffer b;
  luaL_buffinit(L, &b);
  for (;;) {
    char *p = luaL_prepbuffer(&b);
    if (!fgets(p, LUAL_BUFFERSIZE, f))  /* read fails? */
      break;
    n = strlen(p);
    if (p[n-1] != '\n')
      luaL_addsize(&b, n); 
    else {
      luaL_addsize(&b, n-1);  /* do not add the `\n' */
      break;
    }
  }
  luaL_pushresult(&b);  /* close buffer */
  return (n > 0);  /* read something? */
}


static void read_file (lua_State *L, FILE *f) {
  size_t len = 0;
  size_t size = BUFSIZ;
  char *buffer = NULL;
  for (;;) {
    char *newbuffer = (char *)realloc(buffer, size);
    if (newbuffer == NULL) {
      free(buffer);
      lua_error(L, "not enough memory to read a file");
    }
    buffer = newbuffer;
    len += fread(buffer+len, sizeof(char), size-len, f);
    if (len < size) break;  /* did not read all it could */
    size *= 2;
  }
  lua_pushlstring(L, buffer, len);
  free(buffer);
}