io.c

   1 /* Copyright (c) 2006-2013 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 bool
 113 argv_contains(const char **argv, const char *arg)
 114 {
 115         int i;
 116
 117         for (i = 0; argv && argv[i]; i++)
 118                 if (!strcmp(argv[i], arg))
 119                         return TRUE;
 120         return FALSE;
 121 }
 122
 123 DEFINE_ALLOCATOR(argv_realloc, const char *, SIZEOF_ARG)
 124
 125 bool
 126 argv_append(const char ***argv, const char *arg)
 127 {
 128         size_t argc = argv_size(*argv);
 129         char *alloc;
 130
 131         if (!*arg && argc > 0)
 132                 return TRUE;
 133
 134         if (!argv_realloc(argv, argc, 2))
 135                 return FALSE;
 136
 137         alloc = strdup(arg);
 138
 139         (*argv)[argc++] = alloc;
 140         (*argv)[argc] = NULL;
 141
 142         return alloc != NULL;
 143 }
 144
 145 bool
 146 argv_append_array(const char ***dst_argv, const char *src_argv[])
 147 {
 148         int i;
 149
 150         for (i = 0; src_argv && src_argv[i]; i++)
 151                 if (!argv_append(dst_argv, src_argv[i]))
 152                         return FALSE;
 153         return TRUE;
 154 }
 155
 156 bool
 157 argv_remove_quotes(const char *argv[])
 158 {
 159         int argc;
 160
 161         for (argc = 0; argv[argc]; argc++) {
 162                 char quoted = 0;
 163                 const char *arg = argv[argc];
 164                 int arglen = get_arg_valuelen(arg, &quoted);
 165                 int unquotedlen = arglen - 1 - (arg[arglen - 1] == quoted);
 166                 char *unquoted;
 167
 168                 if (!quoted)
 169                         continue;
 170
 171                 unquoted = malloc(unquotedlen + 1);
 172                 if (!unquoted)
 173                         return FALSE;
 174                 strncpy(unquoted, arg + 1, unquotedlen);
 175                 unquoted[unquotedlen] = 0;
 176                 free((void *) arg);
 177                 argv[argc] = unquoted;
 178         }
 179
 180         return TRUE;
 181 }
 182
 183 bool
 184 argv_copy(const char ***dst, const char *src[])
 185 {
 186         int argc;
 187
 188         argv_free(*dst);
 189         for (argc = 0; src[argc]; argc++)
 190                 if (!argv_append(dst, src[argc]))
 191                         return FALSE;
 192         return TRUE;
 193 }
 194
 195 /*
 196  * Encoding conversion.
 197  */
 198
 199 struct encoding {
 200         struct encoding *next;
 201         iconv_t cd;
 202         char fromcode[1];
 203 };
 204
 205 static struct encoding *encodings;
 206
 207 struct encoding *
 208 encoding_open(const char *fromcode)
 209 {
 210         struct encoding *encoding;
 211         size_t len = strlen(fromcode);
 212
 213         if (!*fromcode)
 214                 return NULL;
 215
 216         for (encoding = encodings; encoding; encoding = encoding->next) {
 217                 if (!strcasecmp(encoding->fromcode, fromcode))
 218                         return encoding;
 219         }
 220
 221         encoding = calloc(1, sizeof(*encoding) + len);
 222         strncpy(encoding->fromcode, fromcode, len);
 223         encoding->cd = iconv_open(ENCODING_UTF8, fromcode);
 224         if (encoding->cd == ICONV_NONE) {
 225                 free(encoding);
 226                 return NULL;
 227         }
 228
 229         encoding->next = encodings;
 230         encodings = encoding;
 231
 232         return encoding;
 233 }
 234
 235 static char *
 236 encoding_convert_string(iconv_t iconv_cd, char *line)
 237 {
 238         static char out_buffer[BUFSIZ * 2];
 239         ICONV_CONST char *inbuf = line;
 240         size_t inlen = strlen(line) + 1;
 241
 242         char *outbuf = out_buffer;
 243         size_t outlen = sizeof(out_buffer);
 244
 245         size_t ret = iconv(iconv_cd, &inbuf, &inlen, &outbuf, &outlen);
 246
 247         return (ret != (size_t) -1) ? out_buffer : line;
 248 }
 249
 250 char *
 251 encoding_convert(struct encoding *encoding, char *line)
 252 {
 253         return encoding_convert_string(encoding->cd, line);
 254 }
 255
 256 const char *
 257 encoding_iconv(iconv_t iconv_cd, const char *string)
 258 {
 259         char *instr = strdup(string);
 260         const char *ret = encoding_convert_string(iconv_cd, instr);
 261
 262         free(instr);
 263         return ret == instr ? string : ret;
 264 }
 265
 266 /*
 267  * Executing external commands.
 268  */
 269
 270 static void
 271 io_init(struct io *io)
 272 {
 273         memset(io, 0, sizeof(*io));
 274         io->pipe = -1;
 275 }
 276
 277 bool
 278 io_open(struct io *io, const char *fmt, ...)
 279 {
 280         char name[SIZEOF_STR] = "";
 281         int retval;
 282
 283         io_init(io);
 284
 285         FORMAT_BUFFER(name, sizeof(name), fmt, retval, FALSE);
 286         if (retval < 0) {
 287                 io->error = ENAMETOOLONG;
 288                 return FALSE;
 289         }
 290
 291         io->pipe = *name ? open(name, O_RDONLY) : dup(STDIN_FILENO);
 292         if (io->pipe == -1)
 293                 io->error = errno;
 294         return io->pipe != -1;
 295 }
 296
 297 bool
 298 io_kill(struct io *io)
 299 {
 300         return io->pid == 0 || kill(io->pid, SIGKILL) != -1;
 301 }
 302
 303 bool
 304 io_done(struct io *io)
 305 {
 306         pid_t pid = io->pid;
 307
 308         if (io->pipe != -1)
 309                 close(io->pipe);
 310         free(io->buf);
 311         io_init(io);
 312
 313         while (pid > 0) {
 314                 int status;
 315                 pid_t waiting = waitpid(pid, &status, 0);
 316
 317                 if (waiting < 0) {
 318                         if (errno == EINTR)
 319                                 continue;
 320                         io->error = errno;
 321                         return FALSE;
 322                 }
 323
 324                 if (WEXITSTATUS(status)) {
 325                         io->status = WEXITSTATUS(status);
 326                 }
 327
 328                 return waiting == pid &&
 329                        !WIFSIGNALED(status) &&
 330                        !io->status;
 331         }
 332
 333         return TRUE;
 334 }
 335
 336 static int
 337 open_trace(int devnull, const char *argv[])
 338 {
 339         static const char *trace_file;
 340
 341         if (!trace_file) {
 342                 trace_file = getenv("TIG_TRACE");
 343                 if (!trace_file)
 344                         trace_file = "";
 345         }
 346
 347         if (*trace_file) {
 348                 int fd = open(trace_file, O_RDWR | O_CREAT | O_APPEND, 0666);
 349                 int i;
 350
 351                 for (i = 0; argv[i]; i++) {
 352                         if (write(fd, argv[i], strlen(argv[i])) == -1
 353                             || write(fd, " ", 1) == -1)
 354                                 break;
 355                 }
 356                 if (argv[i] || write(fd, "\n", 1) == -1) {
 357                         close(fd);
 358                         return devnull;
 359                 }
 360
 361                 return fd;
 362         }
 363
 364         return devnull;
 365 }
 366
 367 bool
 368 io_run(struct io *io, enum io_type type, const char *dir, char * const env[], const char *argv[], ...)
 369 {
 370         int pipefds[2] = { -1, -1 };
 371         va_list args;
 372         bool read_from_stdin = type == IO_RD_STDIN;
 373
 374         io_init(io);
 375
 376         if (read_from_stdin)
 377                 type = IO_RD;
 378
 379         if (dir && !strcmp(dir, argv[0]))
 380                 return io_open(io, "%s%s", dir, argv[1]);
 381
 382         if ((type == IO_RD || type == IO_WR) && pipe(pipefds) < 0) {
 383                 io->error = errno;
 384                 return FALSE;
 385         } else if (type == IO_AP) {
 386                 va_start(args, argv);
 387                 pipefds[1] = va_arg(args, int);
 388                 va_end(args);
 389         }
 390
 391         if ((io->pid = fork())) {
 392                 if (io->pid == -1)
 393                         io->error = errno;
 394                 if (pipefds[!(type == IO_WR)] != -1)
 395                         close(pipefds[!(type == IO_WR)]);
 396                 if (io->pid != -1) {
 397                         io->pipe = pipefds[!!(type == IO_WR)];
 398                         return TRUE;
 399                 }
 400
 401         } else {
 402                 if (type != IO_FG) {
 403                         int devnull = open("/dev/null", O_RDWR);
 404                         int readfd  = type == IO_WR ? pipefds[0] : devnull;
 405                         int writefd = (type == IO_RD || type == IO_AP)
 406                                                         ? pipefds[1] : devnull;
 407                         int errorfd = open_trace(devnull, argv);
 408
 409                         /* Inject stdin given on the command line. */
 410                         if (read_from_stdin)
 411                                 readfd = dup(STDIN_FILENO);
 412
 413                         dup2(readfd,  STDIN_FILENO);
 414                         dup2(writefd, STDOUT_FILENO);
 415                         dup2(errorfd, STDERR_FILENO);
 416
 417                         if (devnull != errorfd)
 418                                 close(errorfd);
 419                         close(devnull);
 420                         if (pipefds[0] != -1)
 421                                 close(pipefds[0]);
 422                         if (pipefds[1] != -1)
 423                                 close(pipefds[1]);
 424                 }
 425
 426                 if (dir && *dir && chdir(dir) == -1)
 427                         exit(errno);
 428
 429                 if (env) {
 430                         int i;
 431
 432                         for (i = 0; env[i]; i++)
 433                                 if (*env[i])
 434                                         putenv(env[i]);
 435                 }
 436
 437                 execvp(argv[0], (char *const*) argv);
 438                 exit(errno);
 439         }
 440
 441         if (pipefds[!!(type == IO_WR)] != -1)
 442                 close(pipefds[!!(type == IO_WR)]);
 443         return FALSE;
 444 }
 445
 446 bool
 447 io_complete(enum io_type type, const char **argv, const char *dir, int fd)
 448 {
 449         struct io io;
 450
 451         return io_run(&io, type, dir, NULL, argv, fd) && io_done(&io);
 452 }
 453
 454 bool
 455 io_run_bg(const char **argv)
 456 {
 457         return io_complete(IO_BG, argv, NULL, -1);
 458 }
 459
 460 bool
 461 io_run_fg(const char **argv, const char *dir)
 462 {
 463         return io_complete(IO_FG, argv, dir, -1);
 464 }
 465
 466 bool
 467 io_run_append(const char **argv, int fd)
 468 {
 469         return io_complete(IO_AP, argv, NULL, fd);
 470 }
 471
 472 bool
 473 io_eof(struct io *io)
 474 {
 475         return io->eof;
 476 }
 477
 478 int
 479 io_error(struct io *io)
 480 {
 481         return io->error;
 482 }
 483
 484 char *
 485 io_strerror(struct io *io)
 486 {
 487         return strerror(io->error);
 488 }
 489
 490 bool
 491 io_can_read(struct io *io, bool can_block)
 492 {
 493         struct timeval tv = { 0, 500 };
 494         fd_set fds;
 495
 496         FD_ZERO(&fds);
 497         FD_SET(io->pipe, &fds);
 498
 499         return select(io->pipe + 1, &fds, NULL, NULL, can_block ? NULL : &tv) > 0;
 500 }
 501
 502 ssize_t
 503 io_read(struct io *io, void *buf, size_t bufsize)
 504 {
 505         do {
 506                 ssize_t readsize = read(io->pipe, buf, bufsize);
 507
 508                 if (readsize < 0 && (errno == EAGAIN || errno == EINTR))
 509                         continue;
 510                 else if (readsize == -1)
 511                         io->error = errno;
 512                 else if (readsize == 0)
 513                         io->eof = 1;
 514                 return readsize;
 515         } while (1);
 516 }
 517
 518 DEFINE_ALLOCATOR(io_realloc_buf, char, BUFSIZ)
 519
 520 char *
 521 io_get(struct io *io, int c, bool can_read)
 522 {
 523         char *eol;
 524         ssize_t readsize;
 525
 526         while (TRUE) {
 527                 if (io->bufsize > 0) {
 528                         eol = memchr(io->bufpos, c, io->bufsize);
 529                         if (eol) {
 530                                 char *line = io->bufpos;
 531
 532                                 *eol = 0;
 533                                 io->bufpos = eol + 1;
 534                                 io->bufsize -= io->bufpos - line;
 535                                 return line;
 536                         }
 537                 }
 538
 539                 if (io_eof(io)) {
 540                         if (io->bufsize) {
 541                                 io->bufpos[io->bufsize] = 0;
 542                                 io->bufsize = 0;
 543                                 return io->bufpos;
 544                         }
 545                         return NULL;
 546                 }
 547
 548                 if (!can_read)
 549                         return NULL;
 550
 551                 if (io->bufsize > 0 && io->bufpos > io->buf)
 552                         memmove(io->buf, io->bufpos, io->bufsize);
 553
 554                 if (io->bufalloc == io->bufsize) {
 555                         if (!io_realloc_buf(&io->buf, io->bufalloc, BUFSIZ))
 556                                 return NULL;
 557                         io->bufalloc += BUFSIZ;
 558                 }
 559
 560                 io->bufpos = io->buf;
 561                 readsize = io_read(io, io->buf + io->bufsize, io->bufalloc - io->bufsize);
 562                 if (io_error(io))
 563                         return NULL;
 564                 io->bufsize += readsize;
 565         }
 566 }
 567
 568 bool
 569 io_write(struct io *io, const void *buf, size_t bufsize)
 570 {
 571         size_t written = 0;
 572
 573         while (!io_error(io) && written < bufsize) {
 574                 ssize_t size;
 575
 576                 size = write(io->pipe, buf + written, bufsize - written);
 577                 if (size < 0 && (errno == EAGAIN || errno == EINTR))
 578                         continue;
 579                 else if (size == -1)
 580                         io->error = errno;
 581                 else
 582                         written += size;
 583         }
 584
 585         return written == bufsize;
 586 }
 587
 588 bool
 589 io_printf(struct io *io, const char *fmt, ...)
 590 {
 591         char buf[SIZEOF_STR] = "";
 592         int retval;
 593
 594         FORMAT_BUFFER(buf, sizeof(buf), fmt, retval, FALSE);
 595         if (retval < 0) {
 596                 io->error = ENAMETOOLONG;
 597                 return FALSE;
 598         }
 599
 600         return io_write(io, buf, retval);
 601 }
 602
 603 bool
 604 io_read_buf(struct io *io, char buf[], size_t bufsize)
 605 {
 606         char *result = io_get(io, '\n', TRUE);
 607
 608         if (result) {
 609                 result = chomp_string(result);
 610                 string_ncopy_do(buf, bufsize, result, strlen(result));
 611         }
 612
 613         return io_done(io) && result;
 614 }
 615
 616 bool
 617 io_run_buf(const char **argv, char buf[], size_t bufsize)
 618 {
 619         struct io io;
 620
 621         return io_run(&io, IO_RD, NULL, NULL, argv) && io_read_buf(&io, buf, bufsize);
 622 }
 623
 624 int
 625 io_load(struct io *io, const char *separators,
 626         io_read_fn read_property, void *data)
 627 {
 628         char *name;
 629         int state = OK;
 630
 631         while (state == OK && (name = io_get(io, '\n', TRUE))) {
 632                 char *value;
 633                 size_t namelen;
 634                 size_t valuelen;
 635
 636                 name = chomp_string(name);
 637                 namelen = strcspn(name, separators);
 638
 639                 if (name[namelen]) {
 640                         name[namelen] = 0;
 641                         value = chomp_string(name + namelen + 1);
 642                         valuelen = strlen(value);
 643
 644                 } else {
 645                         value = "";
 646                         valuelen = 0;
 647                 }
 648
 649                 state = read_property(name, namelen, value, valuelen, data);
 650         }
 651
 652         if (state != ERR && io_error(io))
 653                 state = ERR;
 654         io_done(io);
 655
 656         return state;
 657 }
 658
 659 int
 660 io_run_load(const char **argv, const char *separators,
 661             io_read_fn read_property, void *data)
 662 {
 663         struct io io;
 664
 665         if (!io_run(&io, IO_RD, NULL, NULL, argv))
 666                 return ERR;
 667         return io_load(&io, separators, read_property, data);
 668 }
 669
 670 /* vim: set ts=8 sw=8 noexpandtab: */