io.c

   1 /* Copyright (c) 2006-2012 Jonas Fonseca <fonseca@diku.dk>
   2  *
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU General Public License as
   5  * published by the Free Software Foundation; either version 2 of
   6  * the License, or (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include "tig.h"
  15 #include "io.h"
  16
  17 bool
  18 argv_to_string(const char *argv[SIZEOF_ARG], char *buf, size_t buflen, const char *sep)
  19 {
  20         size_t bufpos, argc;
  21
  22         for (bufpos = 0, argc = 0; argv[argc]; argc++)
  23                 if (!string_nformat(buf, buflen, &bufpos, "%s%s",
  24                                 argc ? sep : "", argv[argc]))
  25                         return FALSE;
  26
  27         return TRUE;
  28 }
  29
  30 static inline int
  31 get_arg_valuelen(const char *arg, char *quoted)
  32 {
  33         if (*arg == '"' || *arg == '\'') {
  34                 const char *end = *arg == '"' ? "\"" : "'";
  35                 int valuelen = strcspn(arg + 1, end);
  36
  37                 if (quoted)
  38                         *quoted = *arg;
  39                 return valuelen > 0 ? valuelen + 2 : strlen(arg);
  40         } else {
  41                 if (quoted)
  42                         *quoted = 0;
  43                 return strcspn(arg, " \t");
  44         }
  45 }
  46
  47 static bool
  48 split_argv_string(const char *argv[SIZEOF_ARG], int *argc, char *cmd, bool remove_quotes)
  49 {
  50         while (*cmd && *argc < SIZEOF_ARG) {
  51                 char quoted = 0;
  52                 int valuelen = get_arg_valuelen(cmd, &quoted);
  53                 bool advance = cmd[valuelen] != 0;
  54                 int quote_offset = !!(quoted && remove_quotes);
  55
  56                 cmd[valuelen - quote_offset] = 0;
  57                 argv[(*argc)++] = chomp_string(cmd + quote_offset);
  58                 cmd = chomp_string(cmd + valuelen + advance);
  59         }
  60
  61         if (*argc < SIZEOF_ARG)
  62                 argv[*argc] = NULL;
  63         return *argc < SIZEOF_ARG;
  64 }
  65
  66 bool
  67 argv_from_string_no_quotes(const char *argv[SIZEOF_ARG], int *argc, char *cmd)
  68 {
  69         return split_argv_string(argv, argc, cmd, TRUE);
  70 }
  71
  72 bool
  73 argv_from_string(const char *argv[SIZEOF_ARG], int *argc, char *cmd)
  74 {
  75         return split_argv_string(argv, argc, cmd, FALSE);
  76 }
  77
  78 bool
  79 argv_from_env(const char **argv, const char *name)
  80 {
  81         char *env = argv ? getenv(name) : NULL;
  82         int argc = 0;
  83
  84         if (env && *env)
  85                 env = strdup(env);
  86         return !env || argv_from_string(argv, &argc, env);
  87 }
  88
  89 void
  90 argv_free(const char *argv[])
  91 {
  92         int argc;
  93
  94         if (!argv)
  95                 return;
  96         for (argc = 0; argv[argc]; argc++)
  97                 free((void *) argv[argc]);
  98         argv[0] = NULL;
  99 }
 100
 101 size_t
 102 argv_size(const char **argv)
 103 {
 104         int argc = 0;
 105
 106         while (argv && argv[argc])
 107                 argc++;
 108
 109         return argc;
 110 }
 111
 112 DEFINE_ALLOCATOR(argv_realloc, const char *, SIZEOF_ARG)
 113
 114 bool
 115 argv_append(const char ***argv, const char *arg)
 116 {
 117         size_t argc = argv_size(*argv);
 118         char *alloc;
 119
 120         if (!*arg && argc > 0)
 121                 return TRUE;
 122
 123         if (!argv_realloc(argv, argc, 2))
 124                 return FALSE;
 125
 126         alloc = strdup(arg);
 127
 128         (*argv)[argc++] = alloc;
 129         (*argv)[argc] = NULL;
 130
 131         return alloc != NULL;
 132 }
 133
 134 bool
 135 argv_append_array(const char ***dst_argv, const char *src_argv[])
 136 {
 137         int i;
 138
 139         for (i = 0; src_argv && src_argv[i]; i++)
 140                 if (!argv_append(dst_argv, src_argv[i]))
 141                         return FALSE;
 142         return TRUE;
 143 }
 144
 145 bool
 146 argv_remove_quotes(const char *argv[])
 147 {
 148         int argc;
 149
 150         for (argc = 0; argv[argc]; argc++) {
 151                 char quoted = 0;
 152                 const char *arg = argv[argc];
 153                 int arglen = get_arg_valuelen(arg, &quoted);
 154                 int unquotedlen = arglen - 1 - (arg[arglen - 1] == quoted);
 155                 char *unquoted;
 156
 157                 if (!quoted)
 158                         continue;
 159
 160                 unquoted = malloc(unquotedlen + 1);
 161                 if (!unquoted)
 162                         return FALSE;
 163                 strncpy(unquoted, arg + 1, unquotedlen);
 164                 unquoted[unquotedlen] = 0;
 165                 free((void *) arg);
 166                 argv[argc] = unquoted;
 167         }
 168
 169         return TRUE;
 170 }
 171
 172 bool
 173 argv_copy(const char ***dst, const char *src[])
 174 {
 175         int argc;
 176
 177         argv_free(*dst);
 178         for (argc = 0; src[argc]; argc++)
 179                 if (!argv_append(dst, src[argc]))
 180                         return FALSE;
 181         return TRUE;
 182 }
 183
 184 /*
 185  * Encoding conversion.
 186  */
 187
 188 struct encoding {
 189         struct encoding *next;
 190         iconv_t cd;
 191         char fromcode[1];
 192 };
 193
 194 static struct encoding *encodings;
 195
 196 struct encoding *
 197 encoding_open(const char *fromcode)
 198 {
 199         struct encoding *encoding;
 200         size_t len = strlen(fromcode);
 201
 202         if (!*fromcode)
 203                 return NULL;
 204
 205         for (encoding = encodings; encoding; encoding = encoding->next) {
 206                 if (!strcasecmp(encoding->fromcode, fromcode))
 207                         return encoding;
 208         }
 209
 210         encoding = calloc(1, sizeof(*encoding) + len);
 211         strncpy(encoding->fromcode, fromcode, len);
 212         encoding->cd = iconv_open(ENCODING_UTF8, fromcode);
 213         if (encoding->cd == ICONV_NONE) {
 214                 free(encoding);
 215                 return NULL;
 216         }
 217
 218         encoding->next = encodings;
 219         encodings = encoding;
 220
 221         return encoding;
 222 }
 223
 224 char *
 225 encoding_convert(struct encoding *encoding, char *line)
 226 {
 227         static char out_buffer[BUFSIZ * 2];
 228         ICONV_CONST char *inbuf = line;
 229         size_t inlen = strlen(line) + 1;
 230
 231         char *outbuf = out_buffer;
 232         size_t outlen = sizeof(out_buffer);
 233
 234         size_t ret = iconv(encoding->cd, &inbuf, &inlen, &outbuf, &outlen);
 235
 236         return (ret != (size_t) -1) ? out_buffer : line;
 237 }
 238
 239 /*
 240  * Executing external commands.
 241  */
 242
 243 static void
 244 io_init(struct io *io)
 245 {
 246         memset(io, 0, sizeof(*io));
 247         io->pipe = -1;
 248 }
 249
 250 bool
 251 io_open(struct io *io, const char *fmt, ...)
 252 {
 253         char name[SIZEOF_STR] = "";
 254         int retval;
 255
 256         io_init(io);
 257
 258         FORMAT_BUFFER(name, sizeof(name), fmt, retval, FALSE);
 259         if (retval < 0) {
 260                 io->error = ENAMETOOLONG;
 261                 return FALSE;
 262         }
 263
 264         io->pipe = *name ? open(name, O_RDONLY) : dup(STDIN_FILENO);
 265         if (io->pipe == -1)
 266                 io->error = errno;
 267         return io->pipe != -1;
 268 }
 269
 270 bool
 271 io_kill(struct io *io)
 272 {
 273         return io->pid == 0 || kill(io->pid, SIGKILL) != -1;
 274 }
 275
 276 bool
 277 io_done(struct io *io)
 278 {
 279         pid_t pid = io->pid;
 280
 281         if (io->pipe != -1)
 282                 close(io->pipe);
 283         free(io->buf);
 284         io_init(io);
 285
 286         while (pid > 0) {
 287                 int status;
 288                 pid_t waiting = waitpid(pid, &status, 0);
 289
 290                 if (waiting < 0) {
 291                         if (errno == EINTR)
 292                                 continue;
 293                         io->error = errno;
 294                         return FALSE;
 295                 }
 296
 297                 if (WEXITSTATUS(status)) {
 298                         io->status = WEXITSTATUS(status);
 299                 }
 300
 301                 return waiting == pid &&
 302                        !WIFSIGNALED(status) &&
 303                        !io->status;
 304         }
 305
 306         return TRUE;
 307 }
 308
 309 static int
 310 open_trace(int devnull, const char *argv[])
 311 {
 312         static const char *trace_file;
 313
 314         if (!trace_file) {
 315                 trace_file = getenv("TIG_TRACE");
 316                 if (!trace_file)
 317                         trace_file = "";
 318         }
 319
 320         if (*trace_file) {
 321                 int fd = open(trace_file, O_RDWR | O_CREAT | O_APPEND, 0666);
 322                 int i;
 323
 324                 for (i = 0; argv[i]; i++) {
 325                         if (write(fd, argv[i], strlen(argv[i])) == -1
 326                             || write(fd, " ", 1) == -1)
 327                                 break;
 328                 }
 329                 if (argv[i] || write(fd, "\n", 1) == -1) {
 330                         close(fd);
 331                         return devnull;
 332                 }
 333
 334                 return fd;
 335         }
 336
 337         return devnull;
 338 }
 339
 340 bool
 341 io_run(struct io *io, enum io_type type, const char *dir, const char *argv[], ...)
 342 {
 343         int pipefds[2] = { -1, -1 };
 344         va_list args;
 345
 346         io_init(io);
 347
 348         if (dir && !strcmp(dir, argv[0]))
 349                 return io_open(io, "%s%s", dir, argv[1]);
 350
 351         if ((type == IO_RD || type == IO_WR) && pipe(pipefds) < 0) {
 352                 io->error = errno;
 353                 return FALSE;
 354         } else if (type == IO_AP) {
 355                 va_start(args, argv);
 356                 pipefds[1] = va_arg(args, int);
 357                 va_end(args);
 358         }
 359
 360         if ((io->pid = fork())) {
 361                 if (io->pid == -1)
 362                         io->error = errno;
 363                 if (pipefds[!(type == IO_WR)] != -1)
 364                         close(pipefds[!(type == IO_WR)]);
 365                 if (io->pid != -1) {
 366                         io->pipe = pipefds[!!(type == IO_WR)];
 367                         return TRUE;
 368                 }
 369
 370         } else {
 371                 if (type != IO_FG) {
 372                         int devnull = open("/dev/null", O_RDWR);
 373                         int readfd  = type == IO_WR ? pipefds[0] : devnull;
 374                         int writefd = (type == IO_RD || type == IO_AP)
 375                                                         ? pipefds[1] : devnull;
 376                         int errorfd = open_trace(devnull, argv);
 377
 378                         dup2(readfd,  STDIN_FILENO);
 379                         dup2(writefd, STDOUT_FILENO);
 380                         dup2(errorfd, STDERR_FILENO);
 381
 382                         if (devnull != errorfd)
 383                                 close(errorfd);
 384                         close(devnull);
 385                         if (pipefds[0] != -1)
 386                                 close(pipefds[0]);
 387                         if (pipefds[1] != -1)
 388                                 close(pipefds[1]);
 389                 }
 390
 391                 if (dir && *dir && chdir(dir) == -1)
 392                         exit(errno);
 393
 394                 execvp(argv[0], (char *const*) argv);
 395                 exit(errno);
 396         }
 397
 398         if (pipefds[!!(type == IO_WR)] != -1)
 399                 close(pipefds[!!(type == IO_WR)]);
 400         return FALSE;
 401 }
 402
 403 bool
 404 io_complete(enum io_type type, const char **argv, const char *dir, int fd)
 405 {
 406         struct io io;
 407
 408         return io_run(&io, type, dir, argv, fd) && io_done(&io);
 409 }
 410
 411 bool
 412 io_run_bg(const char **argv)
 413 {
 414         return io_complete(IO_BG, argv, NULL, -1);
 415 }
 416
 417 bool
 418 io_run_fg(const char **argv, const char *dir)
 419 {
 420         return io_complete(IO_FG, argv, dir, -1);
 421 }
 422
 423 bool
 424 io_run_append(const char **argv, int fd)
 425 {
 426         return io_complete(IO_AP, argv, NULL, fd);
 427 }
 428
 429 bool
 430 io_eof(struct io *io)
 431 {
 432         return io->eof;
 433 }
 434
 435 int
 436 io_error(struct io *io)
 437 {
 438         return io->error;
 439 }
 440
 441 char *
 442 io_strerror(struct io *io)
 443 {
 444         return strerror(io->error);
 445 }
 446
 447 bool
 448 io_can_read(struct io *io, bool can_block)
 449 {
 450         struct timeval tv = { 0, 500 };
 451         fd_set fds;
 452
 453         FD_ZERO(&fds);
 454         FD_SET(io->pipe, &fds);
 455
 456         return select(io->pipe + 1, &fds, NULL, NULL, can_block ? NULL : &tv) > 0;
 457 }
 458
 459 ssize_t
 460 io_read(struct io *io, void *buf, size_t bufsize)
 461 {
 462         do {
 463                 ssize_t readsize = read(io->pipe, buf, bufsize);
 464
 465                 if (readsize < 0 && (errno == EAGAIN || errno == EINTR))
 466                         continue;
 467                 else if (readsize == -1)
 468                         io->error = errno;
 469                 else if (readsize == 0)
 470                         io->eof = 1;
 471                 return readsize;
 472         } while (1);
 473 }
 474
 475 DEFINE_ALLOCATOR(io_realloc_buf, char, BUFSIZ)
 476
 477 char *
 478 io_get(struct io *io, int c, bool can_read)
 479 {
 480         char *eol;
 481         ssize_t readsize;
 482
 483         while (TRUE) {
 484                 if (io->bufsize > 0) {
 485                         eol = memchr(io->bufpos, c, io->bufsize);
 486                         if (eol) {
 487                                 char *line = io->bufpos;
 488
 489                                 *eol = 0;
 490                                 io->bufpos = eol + 1;
 491                                 io->bufsize -= io->bufpos - line;
 492                                 return line;
 493                         }
 494                 }
 495
 496                 if (io_eof(io)) {
 497                         if (io->bufsize) {
 498                                 io->bufpos[io->bufsize] = 0;
 499                                 io->bufsize = 0;
 500                                 return io->bufpos;
 501                         }
 502                         return NULL;
 503                 }
 504
 505                 if (!can_read)
 506                         return NULL;
 507
 508                 if (io->bufsize > 0 && io->bufpos > io->buf)
 509                         memmove(io->buf, io->bufpos, io->bufsize);
 510
 511                 if (io->bufalloc == io->bufsize) {
 512                         if (!io_realloc_buf(&io->buf, io->bufalloc, BUFSIZ))
 513                                 return NULL;
 514                         io->bufalloc += BUFSIZ;
 515                 }
 516
 517                 io->bufpos = io->buf;
 518                 readsize = io_read(io, io->buf + io->bufsize, io->bufalloc - io->bufsize);
 519                 if (io_error(io))
 520                         return NULL;
 521                 io->bufsize += readsize;
 522         }
 523 }
 524
 525 bool
 526 io_write(struct io *io, const void *buf, size_t bufsize)
 527 {
 528         size_t written = 0;
 529
 530         while (!io_error(io) && written < bufsize) {
 531                 ssize_t size;
 532
 533                 size = write(io->pipe, buf + written, bufsize - written);
 534                 if (size < 0 && (errno == EAGAIN || errno == EINTR))
 535                         continue;
 536                 else if (size == -1)
 537                         io->error = errno;
 538                 else
 539                         written += size;
 540         }
 541
 542         return written == bufsize;
 543 }
 544
 545 bool
 546 io_printf(struct io *io, const char *fmt, ...)
 547 {
 548         char buf[SIZEOF_STR] = "";
 549         int retval;
 550
 551         FORMAT_BUFFER(buf, sizeof(buf), fmt, retval, FALSE);
 552         if (retval < 0) {
 553                 io->error = ENAMETOOLONG;
 554                 return FALSE;
 555         }
 556
 557         return io_write(io, buf, retval);
 558 }
 559
 560 bool
 561 io_read_buf(struct io *io, char buf[], size_t bufsize)
 562 {
 563         char *result = io_get(io, '\n', TRUE);
 564
 565         if (result) {
 566                 result = chomp_string(result);
 567                 string_ncopy_do(buf, bufsize, result, strlen(result));
 568         }
 569
 570         return io_done(io) && result;
 571 }
 572
 573 bool
 574 io_run_buf(const char **argv, char buf[], size_t bufsize)
 575 {
 576         struct io io;
 577
 578         return io_run(&io, IO_RD, NULL, argv) && io_read_buf(&io, buf, bufsize);
 579 }
 580
 581 int
 582 io_load(struct io *io, const char *separators,
 583         io_read_fn read_property, void *data)
 584 {
 585         char *name;
 586         int state = OK;
 587
 588         while (state == OK && (name = io_get(io, '\n', TRUE))) {
 589                 char *value;
 590                 size_t namelen;
 591                 size_t valuelen;
 592
 593                 name = chomp_string(name);
 594                 namelen = strcspn(name, separators);
 595
 596                 if (name[namelen]) {
 597                         name[namelen] = 0;
 598                         value = chomp_string(name + namelen + 1);
 599                         valuelen = strlen(value);
 600
 601                 } else {
 602                         value = "";
 603                         valuelen = 0;
 604                 }
 605
 606                 state = read_property(name, namelen, value, valuelen, data);
 607         }
 608
 609         if (state != ERR && io_error(io))
 610                 state = ERR;
 611         io_done(io);
 612
 613         return state;
 614 }
 615
 616 int
 617 io_run_load(const char **argv, const char *separators,
 618             io_read_fn read_property, void *data)
 619 {
 620         struct io io;
 621
 622         if (!io_run(&io, IO_RD, NULL, argv))
 623                 return ERR;
 624         return io_load(&io, separators, read_property, data);
 625 }