liolib.c
上传用户:yisoukefu
上传日期:2020-08-09
资源大小:39506k
文件大小:13k
- /*
- ** $Id: liolib.c,v 2.72 2006/01/28 12:59:13 roberto Exp $
- ** Standard I/O (and system) library
- ** See Copyright Notice in lua.h
- */
- #include <errno.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #define liolib_c
- #define LUA_LIB
- #include "lua.h"
- #include "lauxlib.h"
- #include "lualib.h"
- #define IO_INPUT 1
- #define IO_OUTPUT 2
- static const char *const fnames[] = {"input", "output"};
- 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 void fileerror (lua_State *L, int arg, const char *filename) {
- lua_pushfstring(L, "%s: %s", filename, strerror(errno));
- luaL_argerror(L, arg, lua_tostring(L, -1));
- }
- #define topfile(L) ((FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE))
- 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 = topfile(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;
- }
- /*
- ** this function has a separated environment, which defines the
- ** correct __close for 'popen' files
- */
- static int io_pclose (lua_State *L) {
- FILE **p = topfile(L);
- int ok = lua_pclose(L, *p);
- if (ok) *p = NULL;
- return pushresult(L, ok, NULL);
- }
- static int io_fclose (lua_State *L) {
- FILE **p = topfile(L);
- int ok = (fclose(*p) == 0);
- if (ok) *p = NULL;
- return pushresult(L, ok, NULL);
- }
- static int aux_close (lua_State *L) {
- lua_getfenv(L, 1);
- lua_getfield(L, -1, "__close");
- return (lua_tocfunction(L, -1))(L);
- }
- 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 io_gc (lua_State *L) {
- FILE *f = *topfile(L);
- /* ignore closed files and standard files */
- if (f != NULL && f != stdin && f != stdout && f != stderr)
- aux_close(L);
- return 0;
- }
- static int io_tostring (lua_State *L) {
- FILE *f = *topfile(L);
- if (f == NULL)
- lua_pushstring(L, "file (closed)");
- else
- lua_pushfstring(L, "file (%p)", f);
- return 1;
- }
- static int io_open (lua_State *L) {
- const char *filename = luaL_checkstring(L, 1);
- const char *mode = luaL_optstring(L, 2, "r");
- FILE **pf = newfile(L);
- *pf = fopen(filename, mode);
- return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
- }
- static int io_popen (lua_State *L) {
- const char *filename = luaL_checkstring(L, 1);
- const char *mode = luaL_optstring(L, 2, "r");
- FILE **pf = newfile(L);
- *pf = lua_popen(L, filename, mode);
- return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
- }
- static int io_tmpfile (lua_State *L) {
- FILE **pf = newfile(L);
- *pf = tmpfile();
- return (*pf == NULL) ? pushresult(L, 0, NULL) : 1;
- }
- static FILE *getiofile (lua_State *L, int findex) {
- FILE *f;
- lua_rawgeti(L, LUA_ENVIRONINDEX, findex);
- f = *(FILE **)lua_touserdata(L, -1);
- if (f == NULL)
- luaL_error(L, "standard %s file is closed", fnames[findex - 1]);
- return f;
- }
- static int g_iofile (lua_State *L, int f, const char *mode) {
- if (!lua_isnoneornil(L, 1)) {
- const char *filename = lua_tostring(L, 1);
- if (filename) {
- FILE **pf = newfile(L);
- *pf = fopen(filename, mode);
- if (*pf == NULL)
- fileerror(L, 1, filename);
- }
- else {
- tofile(L); /* check that it's a valid file handle */
- lua_pushvalue(L, 1);
- }
- lua_rawseti(L, LUA_ENVIRONINDEX, f);
- }
- /* return current value */
- lua_rawgeti(L, LUA_ENVIRONINDEX, f);
- return 1;
- }
- static int io_input (lua_State *L) {
- return g_iofile(L, IO_INPUT, "r");
- }
- static int io_output (lua_State *L) {
- return g_iofile(L, IO_OUTPUT, "w");
- }
- static int io_readline (lua_State *L);
- static void aux_lines (lua_State *L, int idx, int toclose) {
- lua_pushvalue(L, idx);
- lua_pushboolean(L, toclose); /* close/not close file when finished */
- lua_pushcclosure(L, io_readline, 2);
- }
- static int f_lines (lua_State *L) {
- tofile(L); /* check that it's a valid file handle */
- aux_lines(L, 1, 0);
- return 1;
- }
- static int io_lines (lua_State *L) {
- if (lua_isnoneornil(L, 1)) { /* no arguments? */
- /* will iterate over default input */
- lua_rawgeti(L, LUA_ENVIRONINDEX, IO_INPUT);
- return f_lines(L);
- }
- else {
- const char *filename = luaL_checkstring(L, 1);
- FILE **pf = newfile(L);
- *pf = fopen(filename, "r");
- if (*pf == NULL)
- fileerror(L, 1, filename);
- aux_lines(L, lua_gettop(L), 1);
- return 1;
- }
- }
- /*
- ** {======================================================
- ** READ
- ** =======================================================
- */
- static int read_number (lua_State *L, FILE *f) {
- lua_Number d;
- if (fscanf(f, LUA_NUMBER_SCAN, &d) == 1) {
- lua_pushnumber(L, d);
- return 1;
- }
- else return 0; /* read fails */
- }
- 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_strlen(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_strlen(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;
- }
- static int io_read (lua_State *L) {
- return g_read(L, getiofile(L, IO_INPUT), 1);
- }
- static int f_read (lua_State *L) {
- return g_read(L, tofile(L), 2);
- }
- static int io_readline (lua_State *L) {
- FILE *f = *(FILE **)lua_touserdata(L, lua_upvalueindex(1));
- int sucess;
- if (f == NULL) /* file is already closed? */
- luaL_error(L, "file is already closed");
- sucess = read_line(L, f);
- if (ferror(f))
- return luaL_error(L, "%s", strerror(errno));
- if (sucess) return 1;
- else { /* EOF */
- if (lua_toboolean(L, lua_upvalueindex(2))) { /* generator created file? */
- lua_settop(L, 0);
- lua_pushvalue(L, lua_upvalueindex(1));
- aux_close(L); /* close it */
- }
- return 0;
- }
- }
- /* }====================================================== */
- static int g_write (lua_State *L, FILE *f, int arg) {
- int nargs = lua_gettop(L) - 1;
- int status = 1;
- for (; nargs--; arg++) {
- if (lua_type(L, arg) == LUA_TNUMBER) {
- /* optimization: could be done exactly as for strings */
- status = status &&
- fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0;
- }
- else {
- size_t l;
- const char *s = luaL_checklstring(L, arg, &l);
- status = status && (fwrite(s, sizeof(char), l, f) == l);
- }
- }
- return pushresult(L, status, NULL);
- }
- static int io_write (lua_State *L) {
- return g_write(L, getiofile(L, IO_OUTPUT), 1);
- }
- static int f_write (lua_State *L) {
- return g_write(L, tofile(L), 2);
- }
- static int f_seek (lua_State *L) {
- static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
- static const char *const modenames[] = {"set", "cur", "end", NULL};
- FILE *f = tofile(L);
- int op = luaL_checkoption(L, 2, "cur", modenames);
- long offset = luaL_optlong(L, 3, 0);
- op = fseek(f, offset, mode[op]);
- if (op)
- return pushresult(L, 0, NULL); /* error */
- else {
- lua_pushinteger(L, ftell(f));
- return 1;
- }
- }
- static int f_setvbuf (lua_State *L) {
- static const int mode[] = {_IONBF, _IOFBF, _IOLBF};
- static const char *const modenames[] = {"no", "full", "line", NULL};
- FILE *f = tofile(L);
- int op = luaL_checkoption(L, 2, NULL, modenames);
- lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE);
- int res = setvbuf(f, NULL, mode[op], sz);
- return pushresult(L, res == 0, NULL);
- }
- static int io_flush (lua_State *L) {
- return pushresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
- }
- static int f_flush (lua_State *L) {
- return pushresult(L, fflush(tofile(L)) == 0, NULL);
- }
- static const luaL_Reg iolib[] = {
- {"close", io_close},
- {"flush", io_flush},
- {"input", io_input},
- {"lines", io_lines},
- {"open", io_open},
- {"output", io_output},
- {"popen", io_popen},
- {"read", io_read},
- {"tmpfile", io_tmpfile},
- {"type", io_type},
- {"write", io_write},
- {NULL, NULL}
- };
- static const luaL_Reg flib[] = {
- {"close", io_close},
- {"flush", f_flush},
- {"lines", f_lines},
- {"read", f_read},
- {"seek", f_seek},
- {"setvbuf", f_setvbuf},
- {"write", f_write},
- {"__gc", io_gc},
- {"__tostring", io_tostring},
- {NULL, NULL}
- };
- static void createmeta (lua_State *L) {
- luaL_newmetatable(L, LUA_FILEHANDLE); /* create metatable for file handles */
- lua_pushvalue(L, -1); /* push metatable */
- lua_setfield(L, -2, "__index"); /* metatable.__index = metatable */
- luaL_register(L, NULL, flib); /* file methods */
- }
- static void createstdfile (lua_State *L, FILE *f, int k, const char *fname) {
- *newfile(L) = f;
- if (k > 0) {
- lua_pushvalue(L, -1);
- lua_rawseti(L, LUA_ENVIRONINDEX, k);
- }
- lua_setfield(L, -2, fname);
- }
- LUALIB_API int luaopen_io (lua_State *L) {
- createmeta(L);
- /* create (private) environment (with fields IO_INPUT, IO_OUTPUT, __close) */
- lua_createtable(L, 2, 1);
- lua_replace(L, LUA_ENVIRONINDEX);
- /* open library */
- luaL_register(L, LUA_IOLIBNAME, iolib);
- /* create (and set) default files */
- createstdfile(L, stdin, IO_INPUT, "stdin");
- createstdfile(L, stdout, IO_OUTPUT, "stdout");
- createstdfile(L, stderr, 0, "stderr");
- /* create environment for 'popen' */
- lua_getfield(L, -1, "popen");
- lua_createtable(L, 0, 1);
- lua_pushcfunction(L, io_pclose);
- lua_setfield(L, -2, "__close");
- lua_setfenv(L, -2);
- lua_pop(L, 1); /* pop 'popen' */
- /* set default close function */
- lua_pushcfunction(L, io_fclose);
- lua_setfield(L, LUA_ENVIRONINDEX, "__close");
- return 1;
- }