static int pushresult (lua_State *L, int i, const char *filename) {
int en = errno; /* calls to Lua API may change this value */
if (i) {
lua_pushboolean(L, 1);
return 1;
}
else {
lua_pushnil(L);
if (filename)
lua_pushfstring(L, "%s: %s", filename, strerror(en));
else
lua_pushfstring(L, "%s", strerror(en));
lua_pushinteger(L, en);
return 3;
}
}
static int io_type (lua_State *L) {
void *ud;
luaL_checkany(L, 1);
ud = lua_touserdata(L, 1);
lua_getfield(L, LUA_REGISTRYINDEX, LUA_FILEHANDLE);
if (ud == NULL || !lua_getmetatable(L, 1) || !lua_rawequal(L, -2, -1))
lua_pushnil(L); /* not a file */
else if (*((FILE **)ud) == NULL)
lua_pushliteral(L, "closed file");
else
lua_pushliteral(L, "file");
return 1;
}
static FILE *tofile (lua_State *L) {
FILE **f = tofilep(L);
if (*f == NULL)
luaL_error(L, "attempt to use a closed file");
return *f;
}
/*
** When creating file handles, always creates a `closed' file handle
** before opening the actual file; so, if there is a memory error, the
** file is not left opened.
*/
static FILE **newfile (lua_State *L) {
FILE **pf = (FILE **)lua_newuserdata(L, sizeof(FILE *));
*pf = NULL; /* file handle is currently `closed' */
luaL_getmetatable(L, LUA_FILEHANDLE);
lua_setmetatable(L, -2);
return pf;
}
/*
** function to (not) close the standard files stdin, stdout, and stderr
*/
static int io_noclose (lua_State *L) {
lua_pushnil(L);
lua_pushliteral(L, "cannot close standard file");
return 2;
}
/*
** function to close 'popen' files
*/
static int io_pclose (lua_State *L) {
FILE **p = tofilep(L);
int ok = lua_pclose(L, *p);
*p = NULL;
return pushresult(L, ok, NULL);
}
/*
** function to close regular files
*/
static int io_fclose (lua_State *L) {
FILE **p = tofilep(L);
int ok = (fclose(*p) == 0);
*p = NULL;
return pushresult(L, ok, NULL);
}
static int io_close (lua_State *L) {
if (lua_isnone(L, 1))
lua_rawgeti(L, LUA_ENVIRONINDEX, IO_OUTPUT);
tofile(L); /* make sure argument is a file */
return aux_close(L);
}
static int test_eof (lua_State *L, FILE *f) {
int c = getc(f);
ungetc(c, f);
lua_pushlstring(L, NULL, 0);
return (c != EOF);
}
static int read_line (lua_State *L, FILE *f) {
luaL_Buffer b;
luaL_buffinit(L, &b);
for (;;) {
size_t l;
char *p = luaL_prepbuffer(&b);
if (fgets(p, LUAL_BUFFERSIZE, f) == NULL) { /* eof? */
luaL_pushresult(&b); /* close buffer */
return (lua_objlen(L, -1) > 0); /* check whether read something */
}
l = strlen(p);
if (l == 0 || p[l-1] != '\n')
luaL_addsize(&b, l);
else {
luaL_addsize(&b, l - 1); /* do not include `eol' */
luaL_pushresult(&b); /* close buffer */
return 1; /* read at least an `eol' */
}
}
}
static int read_chars (lua_State *L, FILE *f, size_t n) {
size_t rlen; /* how much to read */
size_t nr; /* number of chars actually read */
luaL_Buffer b;
luaL_buffinit(L, &b);
rlen = LUAL_BUFFERSIZE; /* try to read that much each time */
do {
char *p = luaL_prepbuffer(&b);
if (rlen > n) rlen = n; /* cannot read more than asked */
nr = fread(p, sizeof(char), rlen, f);
luaL_addsize(&b, nr);
n -= nr; /* still have to read `n' chars */
} while (n > 0 && nr == rlen); /* until end of count or eof */
luaL_pushresult(&b); /* close buffer */
return (n == 0 || lua_objlen(L, -1) > 0);
}
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;
}
