libs/nixio/src/file.c

   1 /*
   2  * nixio - Linux I/O library for lua
   3  *
   4  *   Copyright (C) 2009 Steven Barth <steven@midlink.org>
   5  *
   6  *  Licensed under the Apache License, Version 2.0 (the "License");
   7  *  you may not use this file except in compliance with the License.
   8  *  You may obtain a copy of the License at
   9  *
  10  *      http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  *  Unless required by applicable law or agreed to in writing, software
  13  *  distributed under the License is distributed on an "AS IS" BASIS,
  14  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  *  See the License for the specific language governing permissions and
  16  *  limitations under the License.
  17  */
  18
  19 #include "nixio.h"
  20 #include <errno.h>
  21 #include <stdlib.h>
  22 #include <stdio.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #include <fcntl.h>
  26 #include <sys/types.h>
  27 #include <sys/stat.h>
  28 #include <sys/param.h>
  29
  30
  31 static int nixio_open(lua_State *L) {
  32         const char *filename = luaL_checklstring(L, 1, NULL);
  33         int flags;
  34
  35         if (lua_isnoneornil(L, 2)) {
  36                 flags = O_RDONLY;
  37         } else if (lua_isnumber(L, 2)) {
  38                 flags = lua_tointeger(L, 2);
  39         } else if (lua_isstring(L, 2)) {
  40                 const char *str = lua_tostring(L, 2);
  41                 if (!strcmp(str, "r")) {
  42                         flags = O_RDONLY;
  43                 } else if (!strcmp(str, "r+")) {
  44                         flags = O_RDWR;
  45                 } else if (!strcmp(str, "w")) {
  46                         flags = O_WRONLY | O_CREAT | O_TRUNC;
  47                 } else if (!strcmp(str, "w+")) {
  48                         flags = O_RDWR | O_CREAT | O_TRUNC;
  49                 } else if (!strcmp(str, "a")) {
  50                         flags = O_WRONLY | O_CREAT | O_APPEND;
  51                 } else if (!strcmp(str, "a+")) {
  52                         flags = O_RDWR | O_CREAT | O_APPEND;
  53                 } else {
  54                         return luaL_argerror(L, 2, "supported values: r, r+, w, w+, a, a+");
  55                 }
  56         } else {
  57                 return luaL_argerror(L, 2, "open flags or string expected");
  58         }
  59
  60         int fd;
  61
  62         do {
  63                 fd = open(filename, flags, nixio__check_mode(L, 3, 0666));
  64         } while (fd == -1 && errno == EINTR);
  65         if (fd == -1) {
  66                 return nixio__perror(L);
  67         }
  68
  69         int *udata = lua_newuserdata(L, sizeof(int));
  70         if (!udata) {
  71                 return luaL_error(L, "out of memory");
  72         }
  73
  74         *udata = fd;
  75
  76         luaL_getmetatable(L, NIXIO_FILE_META);
  77         lua_setmetatable(L, -2);
  78
  79         return 1;
  80 }
  81
  82 static int nixio_open_flags(lua_State *L) {
  83         int mode = 0;
  84         const int j = lua_gettop(L);
  85         for (int i=1; i<=j; i++) {
  86                 const char *flag = luaL_checkstring(L, i);
  87                 if (!strcmp(flag, "append")) {
  88                         mode |= O_APPEND;
  89                 } else if (!strcmp(flag, "creat")) {
  90                         mode |= O_CREAT;
  91                 } else if (!strcmp(flag, "excl")) {
  92                         mode |= O_EXCL;
  93                 } else if (!strcmp(flag, "nonblock") || !strcmp(flag, "ndelay")) {
  94 #ifndef __WINNT__
  95                         mode |= O_NONBLOCK;
  96 #endif
  97                 } else if (!strcmp(flag, "sync")) {
  98 #ifndef __WINNT__
  99                         mode |= O_SYNC;
 100 #endif
 101                 } else if (!strcmp(flag, "trunc")) {
 102                         mode |= O_TRUNC;
 103                 } else if (!strcmp(flag, "rdonly")) {
 104                         mode |= O_RDONLY;
 105                 } else if (!strcmp(flag, "wronly")) {
 106                         mode |= O_WRONLY;
 107                 } else if (!strcmp(flag, "rdwr")) {
 108                         mode |= O_RDWR;
 109                 } else {
 110                         return luaL_argerror(L, i, "supported values: append, creat, "
 111                                         "excl, nonblock, ndelay, sync, trunc");
 112                 }
 113         }
 114         lua_pushinteger(L, mode);
 115         return 1;
 116 }
 117
 118 static int nixio_dup(lua_State *L) {
 119         int oldfd = nixio__checkfd(L, 1);
 120         int newfd = (lua_gettop(L) > 1) ? nixio__checkfd(L, 2) : -1;
 121         int stat  = (newfd == -1) ? dup(oldfd) : dup2(oldfd, newfd);
 122
 123         if (stat == -1) {
 124                 return nixio__perror(L);
 125         } else {
 126                 if (newfd == -1) {
 127                         int *udata = lua_newuserdata(L, sizeof(int));
 128                         if (!udata) {
 129                                 return luaL_error(L, "out of memory");
 130                         }
 131
 132                         *udata = stat;
 133                         luaL_getmetatable(L, NIXIO_FILE_META);
 134                         lua_setmetatable(L, -2);
 135                 } else {
 136                         lua_pushvalue(L, 2);
 137                 }
 138                 return 1;
 139         }
 140 }
 141
 142 static int nixio_pipe(lua_State *L) {
 143         int pipefd[2], *udata;
 144         if (pipe(pipefd)) {
 145                 return nixio__perror(L);
 146         }
 147
 148         luaL_getmetatable(L, NIXIO_FILE_META);
 149         udata = lua_newuserdata(L, sizeof(int));
 150         if (!udata) {
 151                 return luaL_error(L, "out of memory");
 152         }
 153
 154         *udata = pipefd[0];
 155         lua_pushvalue(L, -2);
 156         lua_setmetatable(L, -2);
 157
 158
 159         udata = lua_newuserdata(L, sizeof(int));
 160         if (!udata) {
 161                 return luaL_error(L, "out of memory");
 162         }
 163
 164         *udata = pipefd[1];
 165         lua_pushvalue(L, -3);
 166         lua_setmetatable(L, -2);
 167
 168         return 2;
 169 }
 170
 171 static int nixio_file_write(lua_State *L) {
 172         int fd = nixio__checkfd(L, 1);
 173         size_t len;
 174         ssize_t sent;
 175         const char *data = luaL_checklstring(L, 2, &len);
 176
 177         if (lua_gettop(L) > 2) {
 178                 int offset = luaL_optint(L, 3, 0);
 179                 if (offset) {
 180                         if (offset < len) {
 181                                 data += offset;
 182                                 len -= offset;
 183                         } else {
 184                                 len = 0;
 185                         }
 186                 }
 187
 188                 unsigned int wlen = luaL_optint(L, 4, len);
 189                 if (wlen < len) {
 190                         len = wlen;
 191                 }
 192         }
 193
 194         do {
 195                 sent = write(fd, data, len);
 196         } while(sent == -1 && errno == EINTR);
 197         if (sent >= 0) {
 198                 lua_pushinteger(L, sent);
 199                 return 1;
 200         } else {
 201                 return nixio__perror(L);
 202         }
 203 }
 204
 205 static int nixio_file_read(lua_State *L) {
 206         int fd = nixio__checkfd(L, 1);
 207         char buffer[NIXIO_BUFFERSIZE];
 208         uint req = luaL_checkinteger(L, 2);
 209         int readc;
 210
 211         /* We limit the readsize to NIXIO_BUFFERSIZE */
 212         req = (req > NIXIO_BUFFERSIZE) ? NIXIO_BUFFERSIZE : req;
 213
 214         do {
 215                 readc = read(fd, buffer, req);
 216         } while (readc == -1 && errno == EINTR);
 217
 218         if (readc < 0) {
 219                 return nixio__perror(L);
 220         } else {
 221                 lua_pushlstring(L, buffer, readc);
 222                 return 1;
 223         }
 224 }
 225
 226
 227 static int nixio_file_seek(lua_State *L) {
 228         int fd = nixio__checkfd(L, 1);
 229         off_t len = (off_t)luaL_checknumber(L, 2);
 230         int whence;
 231         const char *whstr = luaL_optlstring(L, 3, "set", NULL);
 232         if (!strcmp(whstr, "set")) {
 233                 whence = SEEK_SET;
 234         } else if (!strcmp(whstr, "cur")) {
 235                 whence = SEEK_CUR;
 236         } else if (!strcmp(whstr, "end")) {
 237                 whence = SEEK_END;
 238         } else {
 239                 return luaL_argerror(L, 3, "supported values: set, cur, end");
 240         }
 241         len = lseek(fd, len, whence);
 242         if (len == -1) {
 243                 return nixio__perror(L);
 244         } else {
 245                 lua_pushnumber(L, len);
 246                 return 1;
 247         }
 248 }
 249
 250 static int nixio_file_tell(lua_State *L) {
 251         int fd = nixio__checkfd(L, 1);
 252         off_t pos = lseek(fd, 0, SEEK_CUR);
 253         if (pos < 0) {
 254                 return nixio__perror(L);
 255         } else {
 256                 lua_pushnumber(L, pos);
 257                 return 1;
 258         }
 259 }
 260
 261 static int nixio_file_stat(lua_State *L) {
 262         nixio_stat_t buf;
 263         if (fstat(nixio__checkfd(L, 1), &buf)) {
 264                 return nixio__perror(L);
 265         } else {
 266                 nixio__push_stat(L, &buf);
 267                 if (lua_isstring(L, 2)) {
 268                         lua_getfield(L, -1, lua_tostring(L, 2));
 269                 }
 270                 return 1;
 271         }
 272 }
 273
 274 static int nixio_file_sync(lua_State *L) {
 275         int fd = nixio__checkfd(L, 1);
 276         int stat;
 277 #if (!defined BSD && !defined __WINNT__)
 278         int dataonly = lua_toboolean(L, 2);
 279         do {
 280                 stat = (dataonly) ? fdatasync(fd) : fsync(fd);
 281         } while (stat == -1 && errno == EINTR);
 282         return nixio__pstatus(L, !stat);
 283 #else
 284         do {
 285                 stat = fsync(fd);
 286         } while (stat == -1 && errno == EINTR);
 287         return nixio__pstatus(L, !stat);
 288 #endif
 289 }
 290
 291 static int nixio_file_lock(lua_State *L) {
 292         int fd = nixio__checkfd(L, 1);
 293         const char *flag = luaL_checkstring(L, 2);
 294         off_t len = (off_t)luaL_optnumber(L, 3, 0);
 295         int stat;
 296
 297         int cmd = 0;
 298         if (!strcmp(flag, "lock")) {
 299                 cmd = F_LOCK;
 300         } else if (!strcmp(flag, "tlock")) {
 301                 cmd = F_TLOCK;
 302         } else if (!strcmp(flag, "ulock")) {
 303                 cmd = F_ULOCK;
 304         } else if (!strcmp(flag, "test")) {
 305                 cmd = F_TEST;
 306         } else {
 307                 return luaL_argerror(L, 2,
 308                                 "supported values: lock, tlock, ulock, test");
 309         }
 310
 311         do {
 312                 stat = lockf(fd, cmd, len);
 313         } while (stat == -1 && errno == EINTR);
 314
 315         return nixio__pstatus(L, !stat);
 316 }
 317
 318 static int nixio_file_close(lua_State *L) {
 319         int *fdp = luaL_checkudata(L, 1, NIXIO_FILE_META);
 320         luaL_argcheck(L, *fdp != -1, 1, "invalid file object");
 321         int res;
 322         do {
 323                 res = close(*fdp);
 324         } while (res == -1 && errno == EINTR);
 325         *fdp = -1;
 326         return nixio__pstatus(L, !res);
 327 }
 328
 329 static int nixio_file__gc(lua_State *L) {
 330         int *fdp = luaL_checkudata(L, 1, NIXIO_FILE_META);
 331         int res;
 332         if (*fdp != -1) {
 333                 do {
 334                         res = close(*fdp);
 335                 } while (res == -1 && errno == EINTR);
 336                 *fdp = -1;
 337         }
 338         return 0;
 339 }
 340
 341 /**
 342  * string representation
 343  */
 344 static int nixio_file__tostring(lua_State *L) {
 345         lua_pushfstring(L, "nixio file %d", nixio__tofd(L, 1));
 346         return 1;
 347 }
 348
 349 /* method table */
 350 static const luaL_reg M[] = {
 351         {"write",               nixio_file_write},
 352         {"read",                nixio_file_read},
 353         {"tell",                nixio_file_tell},
 354         {"seek",                nixio_file_seek},
 355         {"stat",                nixio_file_stat},
 356         {"sync",                nixio_file_sync},
 357         {"lock",                nixio_file_lock},
 358         {"close",               nixio_file_close},
 359         {"__gc",                nixio_file__gc},
 360         {"__tostring",  nixio_file__tostring},
 361         {NULL,                  NULL}
 362 };
 363
 364 /* module table */
 365 static const luaL_reg R[] = {
 366         {"dup",                 nixio_dup},
 367         {"open",                nixio_open},
 368         {"open_flags",  nixio_open_flags},
 369         {"pipe",                nixio_pipe},
 370         {NULL,                  NULL}
 371 };
 372
 373 void nixio_open_file(lua_State *L) {
 374         luaL_register(L, NULL, R);
 375
 376         luaL_newmetatable(L, NIXIO_FILE_META);
 377         luaL_register(L, NULL, M);
 378         lua_pushvalue(L, -1);
 379         lua_setfield(L, -2, "__index");
 380
 381         int *uin  = lua_newuserdata(L, sizeof(int));
 382         int *uout = lua_newuserdata(L, sizeof(int));
 383         int *uerr = lua_newuserdata(L, sizeof(int));
 384
 385         if (!uin || !uout || !uerr) {
 386                 luaL_error(L, "out of memory");
 387         }
 388
 389         *uin  = STDIN_FILENO;
 390         *uout = STDOUT_FILENO;
 391         *uerr = STDERR_FILENO;
 392
 393         for (int i = -4; i < -1; i++) {
 394                 lua_pushvalue(L, -4);
 395                 lua_setmetatable(L, i);
 396         }
 397
 398         lua_setfield(L, -5, "stderr");
 399         lua_setfield(L, -4, "stdout");
 400         lua_setfield(L, -3, "stdin");
 401         lua_setfield(L, -2, "meta_file");
 402 }