io.c

   1 /* Copyright (c) 2006-2010 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 static inline int
  18 get_arg_valuelen(const char *arg, bool *quoted)
  19 {
  20         if (*arg == '"' || *arg == '\'') {
  21                 const char *end = *arg == '"' ? "\"" : "'";
  22                 int valuelen = strcspn(arg + 1, end);
  23
  24                 if (quoted)
  25                         *quoted = TRUE;
  26                 return valuelen > 0 ? valuelen + 2 : strlen(arg);
  27         } else {
  28                 return strcspn(arg, " \t");
  29         }
  30 }
  31
  32 static bool
  33 split_argv_string(const char *argv[SIZEOF_ARG], int *argc, char *cmd, bool remove_quotes)
  34 {
  35         while (*cmd && *argc < SIZEOF_ARG) {
  36                 bool quoted = FALSE;
  37                 int valuelen = get_arg_valuelen(cmd, &quoted);
  38                 bool advance = cmd[valuelen] != 0;
  39                 int quote_offset = !!(quoted && remove_quotes);
  40
  41                 cmd[valuelen - quote_offset] = 0;
  42                 argv[(*argc)++] = chomp_string(cmd + quote_offset);
  43                 cmd = chomp_string(cmd + valuelen + advance);
  44         }
  45
  46         if (*argc < SIZEOF_ARG)
  47                 argv[*argc] = NULL;
  48         return *argc < SIZEOF_ARG;
  49 }
  50
  51 bool
  52 argv_from_string_no_quotes(const char *argv[SIZEOF_ARG], int *argc, char *cmd)
  53 {
  54         return split_argv_string(argv, argc, cmd, TRUE);
  55 }
  56
  57 bool
  58 argv_from_string(const char *argv[SIZEOF_ARG], int *argc, char *cmd)
  59 {
  60         return split_argv_string(argv, argc, cmd, FALSE);
  61 }
  62
  63 bool
  64 argv_from_env(const char **argv, const char *name)
  65 {
  66         char *env = argv ? getenv(name) : NULL;
  67         int argc = 0;
  68
  69         if (env && *env)
  70                 env = strdup(env);
  71         return !env || argv_from_string(argv, &argc, env);
  72 }
  73
  74 void
  75 argv_free(const char *argv[])
  76 {
  77         int argc;
  78
  79         if (!argv)
  80                 return;
  81         for (argc = 0; argv[argc]; argc++)
  82                 free((void *) argv[argc]);
  83         argv[0] = NULL;
  84 }
  85
  86 size_t
  87 argv_size(const char **argv)
  88 {
  89         int argc = 0;
  90
  91         while (argv && argv[argc])
  92                 argc++;
  93
  94         return argc;
  95 }
  96
  97 DEFINE_ALLOCATOR(argv_realloc, const char *, SIZEOF_ARG)
  98
  99 bool
 100 argv_append(const char ***argv, const char *arg)
 101 {
 102         size_t argc = argv_size(*argv);
 103
 104         if (!*arg && argc > 0)
 105                 return TRUE;
 106
 107         if (!argv_realloc(argv, argc, 2))
 108                 return FALSE;
 109
 110         (*argv)[argc++] = strdup(arg);
 111         (*argv)[argc] = NULL;
 112         return TRUE;
 113 }
 114
 115 bool
 116 argv_append_array(const char ***dst_argv, const char *src_argv[])
 117 {
 118         int i;
 119
 120         for (i = 0; src_argv && src_argv[i]; i++)
 121                 if (!argv_append(dst_argv, src_argv[i]))
 122                         return FALSE;
 123         return TRUE;
 124 }
 125
 126 bool
 127 argv_copy(const char ***dst, const char *src[])
 128 {
 129         int argc;
 130
 131         argv_free(*dst);
 132         for (argc = 0; src[argc]; argc++)
 133                 if (!argv_append(dst, src[argc]))
 134                         return FALSE;
 135         return TRUE;
 136 }
 137
 138
 139 /*
 140  * Executing external commands.
 141  */
 142
 143 static void
 144 io_init(struct io *io)
 145 {
 146         memset(io, 0, sizeof(*io));
 147         io->pipe = -1;
 148 }
 149
 150 bool
 151 io_open(struct io *io, const char *fmt, ...)
 152 {
 153         char name[SIZEOF_STR] = "";
 154         int retval;
 155
 156         io_init(io);
 157
 158         FORMAT_BUFFER(name, sizeof(name), fmt, retval);
 159         if (retval < 0) {
 160                 io->error = ENAMETOOLONG;
 161                 return FALSE;
 162         }
 163
 164         io->pipe = *name ? open(name, O_RDONLY) : dup(STDIN_FILENO);
 165         if (io->pipe == -1)
 166                 io->error = errno;
 167         return io->pipe != -1;
 168 }
 169
 170 bool
 171 io_kill(struct io *io)
 172 {
 173         return io->pid == 0 || kill(io->pid, SIGKILL) != -1;
 174 }
 175
 176 bool
 177 io_done(struct io *io)
 178 {
 179         pid_t pid = io->pid;
 180
 181         if (io->pipe != -1)
 182                 close(io->pipe);
 183         free(io->buf);
 184         io_init(io);
 185
 186         while (pid > 0) {
 187                 int status;
 188                 pid_t waiting = waitpid(pid, &status, 0);
 189
 190                 if (waiting < 0) {
 191                         if (errno == EINTR)
 192                                 continue;
 193                         io->error = errno;
 194                         return FALSE;
 195                 }
 196
 197                 return waiting == pid &&
 198                        !WIFSIGNALED(status) &&
 199                        WIFEXITED(status) &&
 200                        !WEXITSTATUS(status);
 201         }
 202
 203         return TRUE;
 204 }
 205
 206 bool
 207 io_run(struct io *io, enum io_type type, const char *dir, const char *argv[], ...)
 208 {
 209         int pipefds[2] = { -1, -1 };
 210         va_list args;
 211
 212         io_init(io);
 213
 214         if (dir && !strcmp(dir, argv[0]))
 215                 return io_open(io, "%s%s", dir, argv[1]);
 216
 217         if ((type == IO_RD || type == IO_WR) && pipe(pipefds) < 0) {
 218                 io->error = errno;
 219                 return FALSE;
 220         } else if (type == IO_AP) {
 221                 va_start(args, argv);
 222                 pipefds[1] = va_arg(args, int);
 223                 va_end(args);
 224         }
 225
 226         if ((io->pid = fork())) {
 227                 if (io->pid == -1)
 228                         io->error = errno;
 229                 if (pipefds[!(type == IO_WR)] != -1)
 230                         close(pipefds[!(type == IO_WR)]);
 231                 if (io->pid != -1) {
 232                         io->pipe = pipefds[!!(type == IO_WR)];
 233                         return TRUE;
 234                 }
 235
 236         } else {
 237                 if (type != IO_FG) {
 238                         int devnull = open("/dev/null", O_RDWR);
 239                         int readfd  = type == IO_WR ? pipefds[0] : devnull;
 240                         int writefd = (type == IO_RD || type == IO_AP)
 241                                                         ? pipefds[1] : devnull;
 242
 243                         dup2(readfd,  STDIN_FILENO);
 244                         dup2(writefd, STDOUT_FILENO);
 245                         dup2(devnull, STDERR_FILENO);
 246
 247                         close(devnull);
 248                         if (pipefds[0] != -1)
 249                                 close(pipefds[0]);
 250                         if (pipefds[1] != -1)
 251                                 close(pipefds[1]);
 252                 }
 253
 254                 if (dir && *dir && chdir(dir) == -1)
 255                         exit(errno);
 256
 257                 execvp(argv[0], (char *const*) argv);
 258                 exit(errno);
 259         }
 260
 261         if (pipefds[!!(type == IO_WR)] != -1)
 262                 close(pipefds[!!(type == IO_WR)]);
 263         return FALSE;
 264 }
 265
 266 bool
 267 io_complete(enum io_type type, const char **argv, const char *dir, int fd)
 268 {
 269         struct io io;
 270
 271         return io_run(&io, type, dir, argv, fd) && io_done(&io);
 272 }
 273
 274 bool
 275 io_run_bg(const char **argv)
 276 {
 277         return io_complete(IO_BG, argv, NULL, -1);
 278 }
 279
 280 bool
 281 io_run_fg(const char **argv, const char *dir)
 282 {
 283         return io_complete(IO_FG, argv, dir, -1);
 284 }
 285
 286 bool
 287 io_run_append(const char **argv, int fd)
 288 {
 289         return io_complete(IO_AP, argv, NULL, fd);
 290 }
 291
 292 bool
 293 io_eof(struct io *io)
 294 {
 295         return io->eof;
 296 }
 297
 298 int
 299 io_error(struct io *io)
 300 {
 301         return io->error;
 302 }
 303
 304 char *
 305 io_strerror(struct io *io)
 306 {
 307         return strerror(io->error);
 308 }
 309
 310 bool
 311 io_can_read(struct io *io, bool can_block)
 312 {
 313         struct timeval tv = { 0, 500 };
 314         fd_set fds;
 315
 316         FD_ZERO(&fds);
 317         FD_SET(io->pipe, &fds);
 318
 319         return select(io->pipe + 1, &fds, NULL, NULL, can_block ? NULL : &tv) > 0;
 320 }
 321
 322 ssize_t
 323 io_read(struct io *io, void *buf, size_t bufsize)
 324 {
 325         do {
 326                 ssize_t readsize = read(io->pipe, buf, bufsize);
 327
 328                 if (readsize < 0 && (errno == EAGAIN || errno == EINTR))
 329                         continue;
 330                 else if (readsize == -1)
 331                         io->error = errno;
 332                 else if (readsize == 0)
 333                         io->eof = 1;
 334                 return readsize;
 335         } while (1);
 336 }
 337
 338 DEFINE_ALLOCATOR(io_realloc_buf, char, BUFSIZ)
 339
 340 char *
 341 io_get(struct io *io, int c, bool can_read)
 342 {
 343         char *eol;
 344         ssize_t readsize;
 345
 346         while (TRUE) {
 347                 if (io->bufsize > 0) {
 348                         eol = memchr(io->bufpos, c, io->bufsize);
 349                         if (eol) {
 350                                 char *line = io->bufpos;
 351
 352                                 *eol = 0;
 353                                 io->bufpos = eol + 1;
 354                                 io->bufsize -= io->bufpos - line;
 355                                 return line;
 356                         }
 357                 }
 358
 359                 if (io_eof(io)) {
 360                         if (io->bufsize) {
 361                                 io->bufpos[io->bufsize] = 0;
 362                                 io->bufsize = 0;
 363                                 return io->bufpos;
 364                         }
 365                         return NULL;
 366                 }
 367
 368                 if (!can_read)
 369                         return NULL;
 370
 371                 if (io->bufsize > 0 && io->bufpos > io->buf)
 372                         memmove(io->buf, io->bufpos, io->bufsize);
 373
 374                 if (io->bufalloc == io->bufsize) {
 375                         if (!io_realloc_buf(&io->buf, io->bufalloc, BUFSIZ))
 376                                 return NULL;
 377                         io->bufalloc += BUFSIZ;
 378                 }
 379
 380                 io->bufpos = io->buf;
 381                 readsize = io_read(io, io->buf + io->bufsize, io->bufalloc - io->bufsize);
 382                 if (io_error(io))
 383                         return NULL;
 384                 io->bufsize += readsize;
 385         }
 386 }
 387
 388 bool
 389 io_write(struct io *io, const void *buf, size_t bufsize)
 390 {
 391         size_t written = 0;
 392
 393         while (!io_error(io) && written < bufsize) {
 394                 ssize_t size;
 395
 396                 size = write(io->pipe, buf + written, bufsize - written);
 397                 if (size < 0 && (errno == EAGAIN || errno == EINTR))
 398                         continue;
 399                 else if (size == -1)
 400                         io->error = errno;
 401                 else
 402                         written += size;
 403         }
 404
 405         return written == bufsize;
 406 }
 407
 408 bool
 409 io_printf(struct io *io, const char *fmt, ...)
 410 {
 411         char buf[SIZEOF_STR] = "";
 412         int retval;
 413
 414         FORMAT_BUFFER(buf, sizeof(buf), fmt, retval);
 415         if (retval < 0) {
 416                 io->error = ENAMETOOLONG;
 417                 return FALSE;
 418         }
 419
 420         return io_write(io, buf, retval);
 421 }
 422
 423 bool
 424 io_read_buf(struct io *io, char buf[], size_t bufsize)
 425 {
 426         char *result = io_get(io, '\n', TRUE);
 427
 428         if (result) {
 429                 result = chomp_string(result);
 430                 string_ncopy_do(buf, bufsize, result, strlen(result));
 431         }
 432
 433         return io_done(io) && result;
 434 }
 435
 436 bool
 437 io_run_buf(const char **argv, char buf[], size_t bufsize)
 438 {
 439         struct io io;
 440
 441         return io_run(&io, IO_RD, NULL, argv) && io_read_buf(&io, buf, bufsize);
 442 }
 443
 444 int
 445 io_load(struct io *io, const char *separators,
 446         io_read_fn read_property, void *data)
 447 {
 448         char *name;
 449         int state = OK;
 450
 451         while (state == OK && (name = io_get(io, '\n', TRUE))) {
 452                 char *value;
 453                 size_t namelen;
 454                 size_t valuelen;
 455
 456                 name = chomp_string(name);
 457                 namelen = strcspn(name, separators);
 458
 459                 if (name[namelen]) {
 460                         name[namelen] = 0;
 461                         value = chomp_string(name + namelen + 1);
 462                         valuelen = strlen(value);
 463
 464                 } else {
 465                         value = "";
 466                         valuelen = 0;
 467                 }
 468
 469                 state = read_property(name, namelen, value, valuelen, data);
 470         }
 471
 472         if (state != ERR && io_error(io))
 473                 state = ERR;
 474         io_done(io);
 475
 476         return state;
 477 }
 478
 479 int
 480 io_run_load(const char **argv, const char *separators,
 481             io_read_fn read_property, void *data)
 482 {
 483         struct io io;
 484
 485         if (!io_run(&io, IO_RD, NULL, argv))
 486                 return ERR;
 487         return io_load(&io, separators, read_property, data);
 488 }