static int io_popen (lua_State *L) {
#ifndef POPEN
luaL_verror(L, "`popen' not supported");
return 0;
#else
FILE *f = popen(luaL_check_string(L, 1), luaL_opt_string(L, 2, "r"));
return setnewfile(L, f);
#endif
}
scanFile::scanFile(const char * base_name , const char * index_name)
{
assert(basename!=NULL && index_name!=NULL);
index = new indexFile(index_name,indexFile::R);
int len = strlen(base_name);
basename = new char [len + 1];
strcpy(basename,base_name);
filefd = 0;
setnewfile(0);
offset.push_back(0);
page_content = new char [96000];
init();
}
char * scanFile::locate(const int page_num)
{
int number = page_num / MAXFILELIMIT;
if (number!=currentfilenumber)
{
//update filefd , currentfilenumber , currentfilenumber
setnewfile(number);
}
int size_offset = offset.at(page_num-1);
int size = pagesize.at(page_num-1);
//找到数据文件的指定序号的开始位置
lseek(filefd,size_offset,SEEK_SET);
//从上面的文件位置，进行读取
read(filefd,page_content,size);
page_content[size] = '\0';
return page_content;
}
static int io_tmpfile (lua_State *L) {
return setnewfile(L, tmpfile());
}
static int io_open (lua_State *L) {
FILE *f = fopen(luaL_check_string(L, 1), luaL_opt_string(L, 2, "r"));
return setnewfile(L, f);
}
