uspace/lib/posix/src/stdio.c

   1 /*
   2  * Copyright (c) 2011 Jiri Zarevucky
   3  * Copyright (c) 2011 Petr Koupy
   4  * Copyright (c) 2018 Jiri Svoboda
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * - Redistributions of source code must retain the above copyright
  12  *   notice, this list of conditions and the following disclaimer.
  13  * - Redistributions in binary form must reproduce the above copyright
  14  *   notice, this list of conditions and the following disclaimer in the
  15  *   documentation and/or other materials provided with the distribution.
  16  * - The name of the author may not be used to endorse or promote products
  17  *   derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 /** @addtogroup libposix
  32  * @{
  33  */
  34 /** @file Standard buffered input/output.
  35  */
  36
  37 #define _LARGEFILE64_SOURCE
  38 #undef _FILE_OFFSET_BITS
  39
  40 #include "internal/common.h"
  41 #include <stdio.h>
  42
  43 #include <assert.h>
  44 #include <errno.h>
  45 #include <stdbool.h>
  46 #include <tmpfile.h>
  47
  48 #include <fcntl.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <sys/stat.h>
  52 #include <sys/types.h>
  53 #include <unistd.h>
  54
  55 #include <printf_core.h>
  56 #include <str.h>
  57 #include <stdlib.h>
  58 #include <adt/list.h>
  59
  60 /**
  61  * Generate a pathname for the controlling terminal.
  62  *
  63  * @param s Allocated buffer to which the pathname shall be put.
  64  * @return Either s or static location filled with the requested pathname.
  65  */
  66 char *ctermid(char *s)
  67 {
  68         /* Currently always returns an error value (empty string). */
  69         // TODO: return a real terminal path
  70
  71         static char dummy_path[L_ctermid] = { '\0' };
  72
  73         if (s == NULL) {
  74                 return dummy_path;
  75         }
  76
  77         s[0] = '\0';
  78         return s;
  79 }
  80
  81 /**
  82  * Read a stream until the delimiter (or EOF) is encountered.
  83  *
  84  * @param lineptr Pointer to the output buffer in which there will be stored
  85  *     nul-terminated string together with the delimiter (if encountered).
  86  *     Will be resized if necessary.
  87  * @param n Pointer to the size of the output buffer. Will be increased if
  88  *     necessary.
  89  * @param delimiter Delimiter on which to finish reading the stream.
  90  * @param stream Input stream.
  91  * @return Number of fetched characters (including delimiter if encountered)
  92  *     or -1 on error (set in errno).
  93  */
  94 ssize_t getdelim(char **restrict lineptr, size_t *restrict n,
  95     int delimiter, FILE *restrict stream)
  96 {
  97         /* Check arguments for sanity. */
  98         if (!lineptr || !n) {
  99                 errno = EINVAL;
 100                 return -1;
 101         }
 102
 103         size_t alloc_step = 80; /* Buffer size gain during reallocation. */
 104         char *pos = *lineptr; /* Next free byte of the output buffer. */
 105         size_t cnt = 0; /* Number of fetched characters. */
 106         int c = fgetc(stream); /* Current input character. Might be EOF. */
 107
 108         do {
 109                 /* Mask EOF as NUL to terminate string. */
 110                 if (c == EOF) {
 111                         c = '\0';
 112                 }
 113
 114                 /* Ensure there is still space left in the buffer. */
 115                 if (pos == *lineptr + *n) {
 116                         *lineptr = realloc(*lineptr, *n + alloc_step);
 117                         if (*lineptr) {
 118                                 pos = *lineptr + *n;
 119                                 *n += alloc_step;
 120                         } else {
 121                                 errno = ENOMEM;
 122                                 return -1;
 123                         }
 124                 }
 125
 126                 /* Store the fetched character. */
 127                 *pos = c;
 128
 129                 /* Fetch the next character according to the current character. */
 130                 if (c != '\0') {
 131                         ++pos;
 132                         ++cnt;
 133                         if (c == delimiter) {
 134                                 /*
 135                                  * Delimiter was just stored. Provide EOF as the next
 136                                  * character - it will be masked as NUL and output string
 137                                  * will be properly terminated.
 138                                  */
 139                                 c = EOF;
 140                         } else {
 141                                 /*
 142                                  * Neither delimiter nor EOF were encountered. Just fetch
 143                                  * the next character from the stream.
 144                                  */
 145                                 c = fgetc(stream);
 146                         }
 147                 }
 148         } while (c != '\0');
 149
 150         if (errno == EOK && cnt > 0) {
 151                 return cnt;
 152         } else {
 153                 /* Either some error occured or the stream was already at EOF. */
 154                 return -1;
 155         }
 156 }
 157
 158 /**
 159  * Read a stream until the newline (or EOF) is encountered.
 160  *
 161  * @param lineptr Pointer to the output buffer in which there will be stored
 162  *     nul-terminated string together with the delimiter (if encountered).
 163  *     Will be resized if necessary.
 164  * @param n Pointer to the size of the output buffer. Will be increased if
 165  *     necessary.
 166  * @param stream Input stream.
 167  * @return Number of fetched characters (including newline if encountered)
 168  *     or -1 on error (set in errno).
 169  */
 170 ssize_t getline(char **restrict lineptr, size_t *restrict n,
 171     FILE *restrict stream)
 172 {
 173         return getdelim(lineptr, n, '\n', stream);
 174 }
 175
 176 /**
 177  * Reposition a file-position indicator in a stream.
 178  *
 179  * @param stream Stream to seek in.
 180  * @param offset Direction and amount of bytes to seek.
 181  * @param whence From where to seek.
 182  * @return Zero on success, -1 otherwise.
 183  */
 184 int fseeko(FILE *stream, off_t offset, int whence)
 185 {
 186         return fseek(stream, offset, whence);
 187 }
 188
 189 /**
 190  * Discover current file offset in a stream.
 191  *
 192  * @param stream Stream for which the offset shall be retrieved.
 193  * @return Current offset or -1 if not possible.
 194  */
 195 off_t ftello(FILE *stream)
 196 {
 197         return ftell(stream);
 198 }
 199
 200 int fseeko64(FILE *stream, off64_t offset, int whence)
 201 {
 202         return fseek64(stream, offset, whence);
 203 }
 204
 205 off64_t ftello64(FILE *stream)
 206 {
 207         return ftell64(stream);
 208 }
 209
 210 /**
 211  * Print formatted output to the opened file.
 212  *
 213  * @param fildes File descriptor of the opened file.
 214  * @param format Format description.
 215  * @return Either the number of printed characters or negative value on error.
 216  */
 217 int dprintf(int fildes, const char *restrict format, ...)
 218 {
 219         va_list list;
 220         va_start(list, format);
 221         int result = vdprintf(fildes, format, list);
 222         va_end(list);
 223         return result;
 224 }
 225
 226 /**
 227  * Write ordinary string to the opened file.
 228  *
 229  * @param str String to be written.
 230  * @param size Size of the string (in bytes)..
 231  * @param fd File descriptor of the opened file.
 232  * @return The number of written characters.
 233  */
 234 static int _dprintf_str_write(const char *str, size_t size, void *fd)
 235 {
 236         const int fildes = *(int *) fd;
 237         size_t wr;
 238         if (failed(vfs_write(fildes, &posix_pos[fildes], str, size, &wr)))
 239                 return -1;
 240         return str_nlength(str, wr);
 241 }
 242
 243 /**
 244  * Write wide string to the opened file.
 245  *
 246  * @param str String to be written.
 247  * @param size Size of the string (in bytes).
 248  * @param fd File descriptor of the opened file.
 249  * @return The number of written characters.
 250  */
 251 static int _dprintf_wstr_write(const char32_t *str, size_t size, void *fd)
 252 {
 253         size_t offset = 0;
 254         size_t chars = 0;
 255         size_t sz;
 256         char buf[4];
 257
 258         while (offset < size) {
 259                 sz = 0;
 260                 if (chr_encode(str[chars], buf, &sz, sizeof(buf)) != EOK) {
 261                         break;
 262                 }
 263
 264                 const int fildes = *(int *) fd;
 265                 size_t nwr;
 266                 if (vfs_write(fildes, &posix_pos[fildes], buf, sz, &nwr) != EOK)
 267                         break;
 268
 269                 chars++;
 270                 offset += sizeof(char32_t);
 271         }
 272
 273         return chars;
 274 }
 275
 276 /**
 277  * Print formatted output to the opened file.
 278  *
 279  * @param fildes File descriptor of the opened file.
 280  * @param format Format description.
 281  * @param ap Print arguments.
 282  * @return Either the number of printed characters or negative value on error.
 283  */
 284 int vdprintf(int fildes, const char *restrict format, va_list ap)
 285 {
 286         printf_spec_t spec = {
 287                 .str_write = _dprintf_str_write,
 288                 .wstr_write = _dprintf_wstr_write,
 289                 .data = &fildes
 290         };
 291
 292         return printf_core(format, &spec, ap);
 293 }
 294
 295 /**
 296  * Acquire file stream for the thread.
 297  *
 298  * @param file File stream to lock.
 299  */
 300 void flockfile(FILE *file)
 301 {
 302         /* dummy */
 303 }
 304
 305 /**
 306  * Acquire file stream for the thread (non-blocking).
 307  *
 308  * @param file File stream to lock.
 309  * @return Zero for success and non-zero if the lock cannot be acquired.
 310  */
 311 int ftrylockfile(FILE *file)
 312 {
 313         /* dummy */
 314         return 0;
 315 }
 316
 317 /**
 318  * Relinquish the ownership of the locked file stream.
 319  *
 320  * @param file File stream to unlock.
 321  */
 322 void funlockfile(FILE *file)
 323 {
 324         /* dummy */
 325 }
 326
 327 /**
 328  * Get a byte from a stream (thread-unsafe).
 329  *
 330  * @param stream Input file stream.
 331  * @return Either read byte or EOF.
 332  */
 333 int getc_unlocked(FILE *stream)
 334 {
 335         return getc(stream);
 336 }
 337
 338 /**
 339  * Get a byte from the standard input stream (thread-unsafe).
 340  *
 341  * @return Either read byte or EOF.
 342  */
 343 int getchar_unlocked(void)
 344 {
 345         return getchar();
 346 }
 347
 348 /**
 349  * Put a byte on a stream (thread-unsafe).
 350  *
 351  * @param c Byte to output.
 352  * @param stream Output file stream.
 353  * @return Either written byte or EOF.
 354  */
 355 int putc_unlocked(int c, FILE *stream)
 356 {
 357         return putc(c, stream);
 358 }
 359
 360 /**
 361  * Put a byte on the standard output stream (thread-unsafe).
 362  *
 363  * @param c Byte to output.
 364  * @return Either written byte or EOF.
 365  */
 366 int putchar_unlocked(int c)
 367 {
 368         return putchar(c);
 369 }
 370
 371 /** Determine if directory is an 'appropriate' temporary directory.
 372  *
 373  * @param dir Directory path
 374  * @return @c true iff directory is appropriate.
 375  */
 376 static bool is_appropriate_tmpdir(const char *dir)
 377 {
 378         struct stat sbuf;
 379
 380         /* Must not be NULL */
 381         if (dir == NULL)
 382                 return false;
 383
 384         /* Must not be empty */
 385         if (dir[0] == '\0')
 386                 return false;
 387
 388         if (stat(dir, &sbuf) != 0)
 389                 return false;
 390
 391         /* Must be a directory */
 392         if ((sbuf.st_mode & S_IFMT) != S_IFDIR)
 393                 return false;
 394
 395         /* Must be writable */
 396         if (access(dir, W_OK) != 0)
 397                 return false;
 398
 399         return true;
 400 }
 401
 402 /** Construct unique file name.
 403  *
 404  * Never use this function.
 405  *
 406  * @param dir Path to directory, where the file should be created.
 407  * @param pfx Optional prefix up to 5 characters long.
 408  * @return Newly allocated unique path for temporary file. NULL on failure.
 409  */
 410 char *tempnam(const char *dir, const char *pfx)
 411 {
 412         const char *dpref;
 413         char *d;
 414         char *buf;
 415         int rc;
 416
 417         d = getenv("TMPDIR");
 418         if (is_appropriate_tmpdir(d))
 419                 dpref = d;
 420         else if (is_appropriate_tmpdir(dir))
 421                 dpref = dir;
 422         else if (is_appropriate_tmpdir(P_tmpdir))
 423                 dpref = P_tmpdir;
 424         else
 425                 dpref = "/";
 426
 427         if (dpref[strlen(dpref) - 1] != '/')
 428                 rc = asprintf(&buf, "%s/%sXXXXXX", dpref, pfx);
 429         else
 430                 rc = asprintf(&buf, "%s%sXXXXXX", dpref, pfx);
 431
 432         if (rc < 0)
 433                 return NULL;
 434
 435         rc = __tmpfile_templ(buf, false);
 436         if (rc != 0) {
 437                 free(buf);
 438                 return NULL;
 439         }
 440
 441         return buf;
 442 }
 443
 444 /** @}
 445  */