C++ read_chars函数代码示例

static int g_read(lua_State *L, FILE *f, int first)
{
    int nargs = lua_gettop(L) - 1;
    int success;
    int n;
    clearerr(f);

    if(nargs == 0)     /* no arguments? */
    {
        success = read_line(L, f);
        n = first+1;  /* to return 1 result */
    }
    else    /* ensure stack space for all results and for auxlib's buffer */
    {
        luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
        success = 1;

        for(n = first; nargs-- && success; n++)
        {
            if(lua_type(L, n) == LUA_TNUMBER)
            {
                size_t l = (size_t)lua_tointeger(L, n);
                success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
            }
            else
            {
                const char *p = lua_tostring(L, n);
                luaL_argcheck(L, p && p[0] == '*', n, "invalid option");

                switch(p[1])
                {
                case 'n':  /* number */
                    success = read_number(L, f);
                    break;
                case 'l':  /* line */
                    success = read_line(L, f);
                    break;
                case 'a':  /* file */
                    read_chars(L, f, ~((size_t)0));  /* read MAX_SIZE_T chars */
                    success = 1; /* always success */
                    break;
                default:
                    return luaL_argerror(L, n, "invalid format");
                }
            }
        }
    }

    if(ferror(f))
        return pushresult(L, 0, NULL);

    if(!success)
    {
        lua_pop(L, 1);  /* remove last result */
        lua_pushnil(L);  /* push nil instead */
    }

    return n - first;
}

static int
elua_read(lua_State *L)
{
   FILE *f   = tofile(L);
   int nargs = lua_gettop(L) - 1;
   int first = 2;
   int success, n;
   clearerr(f);
   if (!nargs)
     {
        success = read_line(L, f);
        n = first + 1;
     }
   else
     {
        luaL_checkstack(L, nargs + LUA_MINSTACK, "too many arguments");
        success = 1;
        for (n = first; nargs-- && success; ++n)
          {
             if (lua_type(L, n) == LUA_TNUMBER)
               {
                  size_t l = (size_t)lua_tointeger(L, n);
                  success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
               }
             else
               {
                  const char *p = lua_tostring(L, n);
                  luaL_argcheck(L, p && p[0] == '*', n, "invalid option");
                  switch (p[1])
                    {
                       case 'n':
                          success = read_number(L, f);
                          break;
                       case 'l':
                          success = read_line(L, f);
                          break;
                       case 'a':
                          read_chars(L, f, ~((size_t)0));
                          success = 1;
                          break;
                       default:
                          return luaL_argerror(L, n, "invalid format");
                    }
               }
          }
     }
   if (ferror(f))
      return push_ret(L, 0, NULL);
   if (!success)
     {
        lua_pop(L, 1);
        lua_pushnil(L);
     }
   return n - first;
}

static int sgi_set_parttype(struct fdisk_context *cxt, int i,
			    struct fdisk_parttype *t)
{
	if (i >= partitions || !t || t->type > UINT32_MAX)
		return -EINVAL;

	if (sgi_get_num_sectors(cxt, i) == 0)	/* caught already before, ... */ {
		printf(_("Sorry, only for non-empty partitions you can change the tag.\n"));
		return -EINVAL;
	}

	if ((i == 10 && t->type != ENTIRE_DISK) || (i == 8 && t->type != 0))
		printf(_("Consider leaving partition 9 as volume header (0), "
			 "and partition 11 as entire volume (6), as IRIX "
			 "expects it.\n\n"));

	if (((t->type != ENTIRE_DISK) && (t->type != SGI_VOLHDR))
	    && (sgi_get_start_sector(cxt, i) < 1)) {
		read_chars(
			_("It is highly recommended that the partition at offset 0\n"
			  "is of type \"SGI volhdr\", the IRIX system will rely on it to\n"
			  "retrieve from its directory standalone tools like sash and fx.\n"
			  "Only the \"SGI volume\" entire disk section may violate this.\n"
			  "Type YES if you are sure about tagging this partition differently.\n"));
		if (strcmp (line_ptr, _("YES\n")))
			return 1;
	}
	sgilabel->partitions[i].id = SSWAP32(t->type);
	return 0;
}

static int
memfile_read (lua_State *L) {
    MemoryFile *f = luaL_checkudata(L, 1, MEMORYFILE_MT_NAME);
    int nargs = lua_gettop(L) - 1;
    int success;
    int n;

    if (nargs == 0) {   /* no arguments? */
        success = read_line(f, L);
        n = 3;          /* to return 1 result */
    }
    else {  /* ensure stack space for all results and for auxlib's buffer */
        luaL_checkstack(L, nargs + LUA_MINSTACK, "too many arguments");
        success = 1;
        for (n = 2; nargs-- && success; n++) {
            if (lua_type(L, n) == LUA_TNUMBER) {
                size_t l = (size_t) lua_tointeger(L, n);
                success = (l == 0) ? test_eof(f, L) : read_chars(f, L, l);
            }
            else {
                const char *p = lua_tostring(L, n);
                luaL_argcheck(L, p && p[0] == '*', n, "invalid option");
                switch (p[1]) {
                    case 'n':  /* number */
                        success = read_number(f, L);
                        break;
                    case 'l':  /* line */
                        success = read_line(f, L);
                        break;
                    case 'a':  /* all the rest of the file */
                        read_chars(f, L, ~((size_t)0)); /* MAX_SIZE_T bytes */
                        success = 1; /* always success */
                        break;
                    default:
                        return luaL_argerror(L, n, "invalid format");
                }
            }
        }
    }

    if (!success) {
        lua_pop(L, 1);      /* remove last result */
        lua_pushnil(L);     /* push nil instead */
    }

    return n - 2;
}

void
drop_chars (gint fd, gint count)
{
  gchar *buffer;

  buffer = read_chars (fd, count);
  flush_buffer (buffer);
}

/*
 * Ask the user for new partition type information (logical, extended).
 * This function calls the actual partition adding logic - dos_add_partition.
 */
void dos_new_partition(struct fdisk_context *cxt)
{
	int i, free_primary = 0;

	for (i = 0; i < 4; i++)
		free_primary += !ptes[i].part_table->sys_ind;

	if (!free_primary && partitions >= MAXIMUM_PARTS) {
		printf(_("The maximum number of partitions has been created\n"));
		return;
	}

	if (!free_primary) {
		if (extended_offset) {
			printf(_("All primary partitions are in use\n"));
			add_logical(cxt);
		} else
			printf(_("If you want to create more than four partitions, you must replace a\n"
				 "primary partition with an extended partition first.\n"));
	} else if (partitions >= MAXIMUM_PARTS) {
		printf(_("All logical partitions are in use\n"));
		printf(_("Adding a primary partition\n"));
		dos_add_partition(cxt, get_partition(cxt, 0, 4), LINUX_NATIVE);
	} else {
		char c, dflt, line[LINE_LENGTH];

		dflt = (free_primary == 1 && !extended_offset) ? 'e' : 'p';
		snprintf(line, sizeof(line),
			 _("Partition type:\n"
			   "   p   primary (%d primary, %d extended, %d free)\n"
			   "%s\n"
			   "Select (default %c): "),
			 4 - (extended_offset ? 1 : 0) - free_primary, extended_offset ? 1 : 0, free_primary,
			 extended_offset ? _("   l   logical (numbered from 5)") : _("   e   extended"),
			 dflt);

		c = tolower(read_chars(line));
		if (c == '\n') {
			c = dflt;
			printf(_("Using default response %c\n"), c);
		}
		if (c == 'p') {
			int i = get_nonexisting_partition(cxt, 0, 4);
			if (i >= 0)
				dos_add_partition(cxt, i, LINUX_NATIVE);
			return;
		} else if (c == 'l' && extended_offset) {
			add_logical(cxt);
			return;
		} else if (c == 'e' && !extended_offset) {
			int i = get_nonexisting_partition(cxt, 0, 4);
			if (i >= 0)
				dos_add_partition(cxt, i, EXTENDED);
			return;
		} else
			printf(_("Invalid partition type `%c'\n"), c);
	}
}

int read_object_basic(FILE *fp, int *index, object *obj)
{
	int	i;
	char	str[10];
	
/* begin of object data */
	read_int(fp, index);  /* object # */
	
	read_chars(fp, obj->name, sizeof(obj->name));
	read_chars(fp, obj->description, sizeof(obj->description));
	for (i = 0; i != 3; i++)
		read_chars(fp, obj->key[i], sizeof(obj->key[i]));
	read_chars(fp, obj->use_output, sizeof(obj->use_output));
	read_long(fp, &obj->value);
	read_short(fp, &obj->weight);
	
	read_char(fp, &obj->type);
	read_char(fp, &obj->adjustment);
	
	read_short(fp, &obj->shotsmax);
	read_short(fp, &obj->shotscur);
	read_short(fp, &obj->ndice);
	read_short(fp, &obj->sdice);
	read_short(fp, &obj->pdice);
	
	read_char(fp, &obj->armor);
	read_char(fp, &obj->wearflag);
	read_char(fp, &obj->magicpower);
	read_char(fp, &obj->magicrealm);
	read_short(fp, &obj->special);
	read_chars(fp, obj->flags, sizeof(obj->flags));
	read_char(fp, &obj->questnum);
	read_char(fp,&obj->strength);
	read_char(fp,&obj->dexterity);
	read_char(fp,&obj->constitution);
	read_char(fp,&obj->intelligence);
	read_char(fp,&obj->piety);
	for (i = 0; i != 16; i++)
		read_short(fp, &obj->sets_flag[i]);
	read_short(fp,&obj->special1);
	read_long(fp,&obj->special2);
	
/* end of object data */
	return(0);
}

// grabs the 32 bytes for the file at (directory_clus, entry_num) and place it
// where ptr points to
int get_directory_entry(union directory_entry *ptr, unsigned int directory_clus, unsigned int entry_num) {
	unsigned int first_dir_clus, entry_first_byte_offset;
	first_dir_clus = get_first_sector_of_cluster(directory_clus);
	if ((entry_first_byte_offset = 32*entry_num) >= img_info.bytes_per_sec*img_info.sec_per_clus) {
		// bad offset
		return 0;
	}
	read_chars(ptr, entry_first_byte_offset + first_dir_clus*img_info.bytes_per_sec, sizeof(union directory_entry));
	return 1;
}

static int icu_ufile_read(lua_State *L) {
	int nargs = lua_gettop(L) - 1;
	int success;
	int n;
	UFILE* ufile = icu4lua_checkufile(L,1,UFILE_UV_META);
	if (nargs == 0) { // no arguments?
		success = read_line(L, ufile);
		n = 3; // to return 1 result
	}
	else {
		luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
		success = 1;
		for (n = 2; nargs-- && success; n++) {
			if (lua_type(L,n) == LUA_TNUMBER) {
				int32_t l = (int32_t)lua_tointeger(L, n);
				success = (l == 0) ? test_eof(L, ufile) : read_chars(L, ufile, l);
			}
			else {
				const char* p = lua_tostring(L, n);
				luaL_argcheck(L, p && p[0] == '*', n, "invalid option");
				switch(p[1]) {
					case 'n': // number
						success = read_number(L, ufile);
						break;
					case 'l': // line
						success = read_line(L, ufile);
						break;
					case 'a': // file
						read_chars(L, ufile, INT32_MAX);
						success = 1;
						break;
					default:
						return luaL_argerror(L, n, "invalid format");
				}
			}
		}
	}
	if (!success) {
		lua_pop(L,1); // remove last result
		lua_pushnil(L); // push nil instead
	}
	return n - 2;
}

int read_file(union directory_entry *file, unsigned int position, unsigned int size) {
	unsigned int offset, bytes_left, cur_clus, bytes_per_clus, byte_position, nmemb;
	char *buffer;
	bytes_per_clus = img_info.bytes_per_sec*img_info.sec_per_clus;
	buffer = malloc(sizeof(char)*(bytes_per_clus));
	offset = position;
	bytes_left = size;
	cur_clus = get_file_cluster(file);
	while (offset > bytes_per_clus) {
		cur_clus = get_next_cluster_in_fat(cur_clus);
		if (end_of_chain(cur_clus)) {
			free(buffer);
			return 0;
		}
		offset -= bytes_per_clus;
	}
	byte_position = img_info.bytes_per_sec*get_first_sector_of_cluster(cur_clus) + offset;
	if (bytes_left > bytes_per_clus - offset) {
		nmemb = bytes_per_clus - offset;
	} else {
		nmemb = bytes_left;
	}
	read_chars(buffer, byte_position, nmemb);
	fwrite(buffer, sizeof(char), nmemb, stdout);
	bytes_left -= nmemb;
	while (bytes_left > 0) {
		cur_clus = get_next_cluster_in_fat(cur_clus);
		if (end_of_chain(cur_clus)) {
			free(buffer);
			return 0;
		}
		byte_position = img_info.bytes_per_sec*get_first_sector_of_cluster(cur_clus);
		if (bytes_left < bytes_per_clus) {
			nmemb = bytes_left;
		} else {
			nmemb = bytes_per_clus;
		}
		read_chars(buffer, byte_position, nmemb);
		fwrite(buffer, sizeof(char), nmemb, stdout);
		bytes_left -= nmemb;
	}
	return 1;
}

    // File Read Operatings {{{
    int LuaIOLib::g_read (lua_State *lua, FileHandle *file, int first) 
    {
        auto process = proc(lua);
        auto &vfs = process->vfs();

        int nargs = lua_gettop(lua) - 1;
        int success;
        int n;
        //clearerr(file);
        if (nargs == 0) {  /* no arguments? */
            success = read_line(lua, file, 1);
            n = first+1;  /* to return 1 result */
        }
        else {  /* ensure stack space for all results and for auxlib's buffer */
            luaL_checkstack(lua, nargs+LUA_MINSTACK, "too many arguments");
            success = 1;
            for (n = first; nargs-- && success; n++) {
                if (lua_type(lua, n) == LUA_TNUMBER) {
                    size_t l = (size_t)lua_tointeger(lua, n);
                    success = (l == 0) ? file->at_end_of_stream() : read_chars(lua, file, l);
                }
                else {
                    const char *p = lua_tostring(lua, n);
                    luaL_argcheck(lua, p && p[0] == '*', n, "invalid option");
                    switch (p[1]) {
                        case 'n':  /* number */
                            success = read_number(lua, file);
                            break;
                        case 'l':  /* line */
                            success = read_line(lua, file, 1);
                            break;
                        case 'L':  /* line with end-of-line */
                            success = read_line(lua, file, 0);
                            break;
                        case 'a':  /* file */
                            read_all(lua, file);  /* read entire file */
                            success = 1; /* always success */
                            break;
                        default:
                            return luaL_argerror(lua, n, "invalid format");
                    }
                }
            }
        }
        /*
        if (ferror(file))
            return luaL_fileresult(lua, 0, NULL);
            */
        if (!success) {
            lua_pop(lua, 1);  /* remove last result */
            lua_pushnil(lua);  /* push nil instead */
        }
        return n - first;
    }

int get_next_directory_entry(union directory_entry *ptr, unsigned int directory_clus, unsigned int entry_num) {
	unsigned int first_dir_clus, entry_first_byte_offset, next_num;
	next_num = entry_num + 1;
	if ((entry_first_byte_offset = 32*next_num) >= img_info.bytes_per_sec*img_info.sec_per_clus) {
		first_dir_clus = get_first_sector_of_cluster(get_next_cluster_in_fat(directory_clus));
		entry_first_byte_offset -= img_info.bytes_per_sec*img_info.sec_per_clus;
	} else {
		first_dir_clus = get_first_sector_of_cluster(directory_clus);
	}
	read_chars(ptr, entry_first_byte_offset + first_dir_clus*img_info.bytes_per_sec, sizeof(union directory_entry));
	return 1;
}

static int io_read (lua_State *L) {
  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
  int lastarg = lua_gettop(L) - 1;
  int firstarg = 1;
  FILE *f = gethandle(L, ctrl, firstarg);
  int n;
  if (f) firstarg++;
  else f = getfilebyref(L, ctrl, INFILE);  /* get _INPUT */
  lua_pop(L, 1);
  if (firstarg > lastarg) {  /* no arguments? */
    lua_settop(L, 0);  /* erase upvalue and other eventual garbage */
    firstarg = lastarg = 1;  /* correct indices */
    lua_pushstring(L, "*l");  /* push default argument */
  }
  else  /* ensure stack space for all results and for auxlib's buffer */
    luaL_checkstack(L, lastarg-firstarg+1+LUA_MINSTACK, "too many arguments");
  for (n = firstarg; n<=lastarg; n++) {
    int success;
    if (lua_isnumber(L, n))
      success = read_chars(L, f, (size_t)Re(lua_tonumber(L, n)));
    else {
      const char *p = luaL_check_string(L, n);
      if (p[0] != '*')
        success = read_pattern(L, f, p);  /* deprecated! */
      else {
        switch (p[1]) {
          case 'n':  /* number */
            if (!read_number(L, f)) goto endloop;  /* read fails */
            continue;  /* number is already pushed; avoid the "pushstring" */
          case 'l':  /* line */
            success = read_line(L, f);
            break;
          case 'a':  /* file */
            read_file(L, f);
            success = 1; /* always success */
            break;
          case 'w':  /* word */
            success = read_word(L, f);
            break;
          default:
            luaL_argerror(L, n, "invalid format");
            success = 0;  /* to avoid warnings */
        }
      }
    }
    if (!success) {
      lua_pop(L, 1);  /* remove last result */
      break;  /* read fails */
    }
  } endloop:
  return n - firstarg;
}

void read_db() {
#ifdef DEBUG_VALUE
    //char cur_dir[256];
    //GetCurrentDirectory(256, cur_dir);
    //printf("in read_db(): %s\n", cur_dir);
#endif
    GLint charsRead = read_chars();
    GLint mapsRead = read_maps();
    GLint itemsRead = read_items();

    if (charsRead || mapsRead || itemsRead) {
        exit_glut("Error reading database!");
    }
}

boolean put_handler(MiniWebServer& web_server) {
    web_server.send_error_code(200);
    web_server.end_headers();

    const char* length_str = web_server.get_header_value("Content-Length");
    long length = atol(length_str);
    uint32_t start_time = 0;
    boolean watchdog_start = false;

    EthernetClient client = web_server.get_client();

    if (put_handler_fn) {
        (*put_handler_fn)(web_server, START, NULL, length);
    }

    uint32_t i;
    for (i = 0; i < length && client.connected();) {
        int16_t size = read_chars(web_server, client, (uint8_t*)buffer, 64);
        if (!size) {
            if (watchdog_start) {
                if (millis() - start_time > 30000) {
                    // Exit if there has been zero data from connected client
                    // for more than 30 seconds.
#if DEBUG
                    Serial << F("TWS:There has been no data for >30 Sec.\n");
#endif
                    break;
                }
            } else {
                // We have hit an empty buffer, start the watchdog.
                start_time = millis();
                watchdog_start = true;
            }
            continue;
        }
        i += size;
        // Ensure we re-start the watchdog if we get ANY data input.
        watchdog_start = false;

        if (put_handler_fn) {
            (*put_handler_fn)(web_server, WRITE, buffer, size);
        }
    }
    if (put_handler_fn) {
        (*put_handler_fn)(web_server, END, NULL, 0);
    }

    return true;
}