src/roff/pipeline.c

   1 /*@ TODO All this stuff belongs into a library! (and separated, xy_OS.c..)
   2  *
   3  * Copyright (c) 2014 - 2017 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
   4  *
   5  * Copyright (C) 1989 - 1992, 2000 - 2006 Free Software Foundation, Inc.
   6  *      Written by James Clark (jjc@jclark.com)
   7  *
   8  * This is free software; you can redistribute it and/or modify it under
   9  * the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 2, or (at your option) any later
  11  * version.
  12  *
  13  * This is distributed in the hope that it will be useful, but WITHOUT ANY
  14  * WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16  * for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with groff; see the file COPYING.  If not, write to the Free Software
  20  * Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA.
  21  */
  22
  23 #include "config.h"
  24 #include "roff-config.h"
  25
  26 #include <sys/types.h>
  27 #include <sys/wait.h>
  28
  29 #include <errno.h>
  30 #include <signal.h>
  31 #include <stdio.h>
  32 #include <string.h>
  33 #include <unistd.h>
  34
  35 #include "lib.h"
  36
  37 #include "pipeline.h"
  38
  39 /* SVR4 uses WCOREFLG; Net 2 uses WCOREFLAG. */// FIXME -> lib.h?!
  40 #ifndef WCOREFLAG
  41 # ifdef WCOREFLG
  42 #  define WCOREFLAG     WCOREFLG
  43 # endif
  44 #endif
  45 #ifndef WCOREDUMP
  46 # ifdef WCOREFLAG
  47 #  define WCOREDUMP(s)  ((s) & WCOREFLAG)
  48 # else
  49 #  define WCOREDUMP(s)  (0)
  50 # endif
  51 #endif
  52
  53 #define error c_error
  54
  55 // In roff.cpp TODO
  56 #ifdef __cplusplus
  57 extern "C" {
  58 #endif
  59 extern void error(const char *, const char *, const char *, const char *);
  60 extern void c_fatal(const char *, const char *, const char *, const char *);
  61 #ifdef __cplusplus
  62 }
  63 #endif
  64
  65 static void sys_fatal(const char *);
  66 static const char *xstrsignal(int);
  67
  68 #if defined(__MSDOS__) \
  69     || (defined(_WIN32) && !defined(_UWIN) && !defined(__CYGWIN__)) \
  70     || defined(__EMX__)
  71
  72 #include <process.h>
  73 #include <fcntl.h>
  74 #include <string.h>
  75 #include <stdlib.h>
  76
  77 #include "nonposix.h"
  78
  79 static const char *sh = "sh";
  80 static const char *cmd = "cmd";
  81 static const char *command = "command";
  82
  83 extern int strcasecmp(const char *, const char *);
  84
  85 char *sbasename(const char *path) // TODO lib.h
  86 {
  87   char *base;
  88   const char *p1, *p2;
  89
  90   p1 = path;
  91   if ((p2 = strrchr(p1, '\\'))
  92       || (p2 = strrchr(p1, '/'))
  93       || (p2 = strrchr(p1, ':')))
  94     p1 = p2 + 1;
  95   if ((p2 = strrchr(p1, '.'))
  96       && ((strcasecmp(p2, ".exe") == 0)
  97           || (strcasecmp(p2, ".com") == 0)))
  98     ;
  99   else
 100     p2 = p1 + strlen(p1);
 101
 102   base = malloc((size_t)(p2 - p1));
 103   strncpy(base, p1, p2 - p1);
 104   *(base + (p2 - p1)) = '\0';
 105
 106   return(base);
 107 }
 108
 109 /* Get the name of the system shell */// TODO lib.h
 110 char *system_shell_name(void)
 111 {
 112   const char *shell_name;
 113
 114   /*
 115      Use a Unixy shell if it's installed.  Use SHELL if set; otherwise,
 116      let spawnlp try to find sh; if that fails, use COMSPEC if set; if
 117      not, try cmd.exe; if that fails, default to command.com.
 118    */
 119
 120   if ((shell_name = getenv("SHELL")) != NULL)
 121     ;
 122   else if (spawnlp(_P_WAIT, sh, sh, "-c", ":", NULL) == 0)
 123     shell_name = sh;
 124   else if ((shell_name = getenv("COMSPEC")) != NULL)
 125     ;
 126   else if (spawnlp(_P_WAIT, cmd, cmd, "/c", ";", NULL) == 0)
 127     shell_name = cmd;
 128   else
 129     shell_name = command;
 130
 131   return sbasename(shell_name);
 132 }
 133
 134 const char *system_shell_dash_c(void)
 135 {
 136   char *shell_name;
 137   const char *dash_c;
 138
 139   shell_name = system_shell_name();
 140
 141   /* Assume that if the shell name ends in `sh', it's Unixy */
 142   if (strcasecmp(shell_name + strlen(shell_name) - strlen("sh"), "sh") == 0)
 143     dash_c = "-c";
 144   else
 145     dash_c = "/c";
 146
 147   free(shell_name);
 148   return dash_c;
 149 }
 150
 151 int is_system_shell(const char *prog)
 152 {
 153   int result;
 154   char *this_prog, *system_shell;
 155
 156   if (!prog)    /* paranoia */
 157     return 0;
 158
 159   this_prog = sbasename(prog);
 160   system_shell = system_shell_name();
 161
 162   result = strcasecmp(this_prog, system_shell) == 0;
 163
 164   free(this_prog);
 165   free(system_shell);
 166
 167   return result;
 168 }
 169
 170 #ifdef _WIN32
 171 /*
 172   Windows 32 doesn't have fork(), so we need to start asynchronous child
 173   processes with spawn() rather than exec().  If there is more than one
 174   command, i.e., a pipeline, the parent must set up each child's I/O
 175   redirection prior to the spawn.  The original stdout must be restored
 176   before spawning the last process in the pipeline, and the original
 177   stdin must be restored in the parent after spawning the last process
 178   and before waiting for any of the children.
 179 */
 180
 181 int run_pipeline(int ncommands, char ***commands, int no_pipe)
 182 {
 183   int i;
 184   int last_input = 0;   /* pacify some compilers */
 185   int save_stdin = 0;
 186   int save_stdout = 0;
 187   int ret = 0;
 188   char err_str[BUFSIZ];
 189   pid_t pids[MAX_COMMANDS];
 190
 191   for (i = 0; i < ncommands; i++) {
 192     int pdes[2];
 193     pid_t pid;
 194
 195     /* If no_pipe is set, just run the commands in sequence
 196        to show the version numbers */
 197     if (ncommands > 1 && !no_pipe) {
 198       /* last command doesn't need a new pipe */
 199       if (i < ncommands - 1) {
 200         if (pipe(pdes) < 0) {
 201           sprintf(err_str, "%s: pipe", commands[i][0]);
 202           sys_fatal(err_str);
 203         }
 204       }
 205       /* 1st command; writer */
 206       if (i == 0) {
 207         /* save stdin */
 208         if ((save_stdin = dup(STDIN_FILENO)) < 0)
 209           sys_fatal("dup stdin");
 210         /* save stdout */
 211         if ((save_stdout = dup(STDOUT_FILENO)) < 0)
 212           sys_fatal("dup stdout");
 213
 214         /* connect stdout to write end of pipe */
 215         if (dup2(pdes[1], STDOUT_FILENO) < 0) {
 216           sprintf(err_str, "%s: dup2(stdout)", commands[i][0]);
 217           sys_fatal(err_str);
 218         }
 219         if (close(pdes[1]) < 0) {
 220           sprintf(err_str, "%s: close(pipe[WRITE])", commands[i][0]);
 221           sys_fatal(err_str);
 222         }
 223         /*
 224            Save the read end of the pipe so that it can be connected to
 225            stdin of the next program in the pipeline during the next
 226            pass through the loop.
 227         */
 228         last_input = pdes[0];
 229       }
 230       /* reader and writer */
 231       else if (i < ncommands - 1) {
 232         /* connect stdin to read end of last pipe */
 233         if (dup2(last_input, STDIN_FILENO) < 0) {
 234           sprintf(err_str, " %s: dup2(stdin)", commands[i][0]);
 235           sys_fatal(err_str);
 236         }
 237         if (close(last_input) < 0) {
 238           sprintf(err_str, "%s: close(last_input)", commands[i][0]);
 239           sys_fatal(err_str);
 240         }
 241         /* connect stdout to write end of new pipe */
 242         if (dup2(pdes[1], STDOUT_FILENO) < 0) {
 243           sprintf(err_str, "%s: dup2(stdout)", commands[i][0]);
 244           sys_fatal(err_str);
 245         }
 246         if (close(pdes[1]) < 0) {
 247           sprintf(err_str, "%s: close(pipe[WRITE])", commands[i][0]);
 248           sys_fatal(err_str);
 249         }
 250         last_input = pdes[0];
 251       }
 252       /* last command; reader */
 253       else {
 254         /* connect stdin to read end of last pipe */
 255         if (dup2(last_input, STDIN_FILENO) < 0) {
 256           sprintf(err_str, "%s: dup2(stdin)", commands[i][0]);
 257           sys_fatal(err_str);
 258         }
 259         if (close(last_input) < 0) {
 260           sprintf(err_str, "%s: close(last_input)", commands[i][0]);
 261           sys_fatal(err_str);
 262         }
 263         /* restore original stdout */
 264         if (dup2(save_stdout, STDOUT_FILENO) < 0) {
 265           sprintf(err_str, "%s: dup2(save_stdout))", commands[i][0]);
 266           sys_fatal(err_str);
 267         }
 268         /* close stdout copy */
 269         if (close(save_stdout) < 0) {
 270           sprintf(err_str, "%s: close(save_stdout)", commands[i][0]);
 271           sys_fatal(err_str);
 272         }
 273       }
 274     }
 275     if ((pid = spawnvp(_P_NOWAIT, commands[i][0], commands[i])) < 0) {
 276       error("couldn't exec %1: %2",
 277             commands[i][0], strerror(errno), (char *)0);
 278       fflush(stderr);                   /* just in case error() doesn't */
 279       _exit(EXEC_FAILED_EXIT_STATUS);
 280     }
 281     pids[i] = pid;
 282   }
 283
 284   if (ncommands > 1 && !no_pipe) {
 285     /* restore original stdin if it was redirected */
 286     if (dup2(save_stdin, STDIN_FILENO) < 0) {
 287       sprintf(err_str, "dup2(save_stdin))");
 288       sys_fatal(err_str);
 289     }
 290     /* close stdin copy */
 291     if (close(save_stdin) < 0) {
 292       sprintf(err_str, "close(save_stdin)");
 293       sys_fatal(err_str);
 294     }
 295   }
 296
 297   for (i = 0; i < ncommands; i++) {
 298     int status;
 299     pid_t pid;
 300
 301     pid = pids[i];
 302     if ((pid = WAIT(&status, pid, _WAIT_CHILD)) < 0) {
 303       sprintf(err_str, "%s: wait", commands[i][0]);
 304       sys_fatal(err_str);
 305     }
 306     else if (status != 0)
 307       ret |= 1;
 308   }
 309   return ret;
 310 }
 311
 312 #else  /* not _WIN32 */
 313
 314 /* MSDOS doesn't have `fork', so we need to simulate the pipe by running
 315    the programs in sequence with standard streams redirected to and
 316    from temporary files.
 317 */
 318
 319 /* A signal handler that just records that a signal has happened.  */
 320 static int child_interrupted;
 321
 322 static void signal_catcher(int signo)
 323 {
 324   child_interrupted++; // ..not even volatile..
 325 }
 326
 327 int run_pipeline(int ncommands, char ***commands, int no_pipe)
 328 {
 329   int save_stdin = dup(0);
 330   int save_stdout = dup(1);
 331   char *tmpfiles[2];
 332   int infile  = 0;
 333   int outfile = 1;
 334   int i, f, ret = 0;
 335
 336   /* Choose names for a pair of temporary files to implement the pipeline.
 337      Microsoft's `tempnam' uses the directory specified by `getenv("TMP")'
 338      if it exists; in case it doesn't, try the GROFF alternatives, or
 339      `getenv("TEMP")' as last resort -- at least one of these had better
 340      be set, since Microsoft's default has a high probability of failure. */
 341   char *tmpdir;
 342   if ((tmpdir = getenv(U_ROFF_TMPDIR)) == NULL // TODO into a library
 343       && (tmpdir = getenv("TMPDIR")) == NULL)  // TODO as generic thing
 344     tmpdir = getenv("TEMP"); // TODO (also true for perl, sh, etc.
 345
 346   /* Don't use `tmpnam' here: Microsoft's implementation yields unusable
 347      file names if current directory is on network share with read-only
 348      root. */
 349   tmpfiles[0] = tempnam(tmpdir, NULL); // TODO library function to create
 350   tmpfiles[1] = tempnam(tmpdir, NULL); // TODO temporary file (+perl,sh,)
 351
 352   for (i = 0; i < ncommands; i++) {
 353     int exit_status;
 354     RETSIGTYPE (*prev_handler)(int);
 355
 356     if (i && !no_pipe) {
 357       /* redirect stdin from temp file */
 358       f = open(tmpfiles[infile], O_RDONLY|O_BINARY, 0666);
 359       if (f < 0)
 360         sys_fatal("open stdin");
 361       if (dup2(f, 0) < 0)
 362         sys_fatal("dup2 stdin");
 363       if (close(f) < 0)
 364         sys_fatal("close stdin");
 365     }
 366     if ((i < ncommands - 1) && !no_pipe) {
 367       /* redirect stdout to temp file */
 368       f = open(tmpfiles[outfile], O_WRONLY|O_CREAT|O_TRUNC|O_BINARY, 0666);
 369       if (f < 0)
 370         sys_fatal("open stdout");
 371       if (dup2(f, 1) < 0)
 372         sys_fatal("dup2 stdout");
 373       if (close(f) < 0)
 374         sys_fatal("close stdout");
 375     }
 376     else if (dup2(save_stdout, 1) < 0)
 377       sys_fatal("restore stdout");
 378
 379     /* run the program */
 380     child_interrupted = 0;
 381     prev_handler = signal(SIGINT, signal_catcher);
 382     exit_status = spawnvp(P_WAIT, commands[i][0], commands[i]);
 383     signal(SIGINT, prev_handler);
 384     if (child_interrupted) {
 385       error("%1: Interrupted", commands[i][0], (char *)0, (char *)0);
 386       ret |= 2;
 387     }
 388     else if (exit_status < 0) {
 389       error("couldn't exec %1: %2",
 390             commands[i][0], strerror(errno), (char *)0);
 391       fflush(stderr);                   /* just in case error() doesn't */
 392       ret |= 4;
 393     }
 394     if (exit_status != 0)
 395       ret |= 1;
 396     /* There's no sense to continue with the pipe if one of the
 397        programs has ended abnormally, is there? */
 398     if (ret != 0)
 399       break;
 400     /* swap temp files: make output of this program be input for the next */
 401     infile = 1 - infile;
 402     outfile = 1 - outfile;
 403   }
 404   if (dup2(save_stdin, 0) < 0)
 405     sys_fatal("restore stdin");
 406   unlink(tmpfiles[0]);
 407   unlink(tmpfiles[1]);
 408   return ret;
 409 }
 410
 411 #endif /* not _WIN32 */
 412
 413 #else /* not __MSDOS__, not _WIN32 */
 414
 415 int run_pipeline(int ncommands, char ***commands, int no_pipe)
 416 {
 417   int i;
 418   int last_input = 0;
 419   pid_t pids[MAX_COMMANDS];
 420   int ret = 0;
 421   int proc_count = ncommands;
 422
 423   for (i = 0; i < ncommands; i++) {
 424     int pdes[2];
 425     pid_t pid;
 426
 427     if ((i != ncommands - 1) && !no_pipe) {
 428       if (pipe(pdes) < 0)
 429         sys_fatal("pipe");
 430     }
 431     pid = fork();
 432     if (pid < 0)
 433       sys_fatal("fork");
 434     if (pid == 0) {
 435       /* child */
 436       if (last_input != 0) {
 437         if (close(0) < 0)
 438           sys_fatal("close");
 439         if (dup(last_input) < 0)
 440           sys_fatal("dup");
 441         if (close(last_input) < 0)
 442           sys_fatal("close");
 443       }
 444       if ((i != ncommands - 1) && !no_pipe) {
 445         if (close(1) < 0)
 446           sys_fatal("close");
 447         if (dup(pdes[1]) < 0)
 448           sys_fatal("dup");
 449         if (close(pdes[1]) < 0)
 450           sys_fatal("close");
 451         if (close(pdes[0]))
 452           sys_fatal("close");
 453       }
 454       execvp(commands[i][0], commands[i]);
 455       error("couldn't exec %1: %2",
 456             commands[i][0], strerror(errno), (char *)0);
 457       fflush(stderr);                   /* just in case error() doesn't */
 458       _exit(EXEC_FAILED_EXIT_STATUS);
 459     }
 460     /* in the parent */
 461     if (last_input != 0) {
 462       if (close(last_input) < 0)
 463         sys_fatal("close");
 464     }
 465     if ((i != ncommands - 1) && !no_pipe) {
 466       if (close(pdes[1]) < 0)
 467         sys_fatal("close");
 468       last_input = pdes[0];
 469     }
 470     pids[i] = pid;
 471   }
 472   while (proc_count > 0) {
 473     int status;
 474     pid_t pid = wait(&status);
 475
 476     if (pid < 0)
 477       sys_fatal("wait");
 478     for (i = 0; i < ncommands; i++)
 479       if (pids[i] == pid) {
 480         pids[i] = -1;
 481         --proc_count;
 482         if (WIFSIGNALED(status)) {
 483           int sig = WTERMSIG(status);
 484 #ifdef SIGPIPE
 485           if (sig == SIGPIPE) {
 486             if (i == ncommands - 1) {
 487               /* This works around a problem that occurred when using the
 488                  rerasterize action in gxditview.  What seemed to be
 489                  happening (on SunOS 4.1.1) was that pclose() closed the
 490                  pipe and waited for groff, gtroff got a SIGPIPE, but
 491                  gpic blocked writing to gtroff, and so groff blocked
 492                  waiting for gpic and gxditview blocked waiting for
 493                  groff.  I don't understand why gpic wasn't getting a
 494                  SIGPIPE. */
 495               int j;
 496
 497               for (j = 0; j < ncommands; j++)
 498                 if (pids[j] > 0)
 499                   (void)kill(pids[j], SIGPIPE);
 500             }
 501           }
 502           else
 503 #endif /* SIGPIPE */
 504           {
 505             error("%1: %2%3",
 506                   commands[i][0],
 507                   xstrsignal(sig),
 508                   WCOREDUMP(status) ? " (core dumped)" : "");
 509             ret |= 2;
 510           }
 511         }
 512         else if (WIFEXITED(status)) {
 513           int exit_status = WEXITSTATUS(status);
 514
 515           if (exit_status == EXEC_FAILED_EXIT_STATUS)
 516             ret |= 4;
 517           else if (exit_status != 0)
 518             ret |= 1;
 519         }
 520         else
 521           error("unexpected status %1", i_to_a(status), (char *)0, (char *)0);
 522         break;
 523       }
 524   }
 525   return ret;
 526 }
 527
 528 #endif /* not __MSDOS__, not _WIN32 */
 529
 530 static void sys_fatal(const char *s)
 531 {
 532   c_fatal("%1: %2", s, strerror(errno), (char *)0);
 533 }
 534
 535 static const char *xstrsignal(int n)
 536 {
 537   static char buf[sizeof("Signal ") + 1 + sizeof(int) * 3];
 538
 539 #ifdef NSIG /* FIXME no, very wrong is this */
 540 # if HAVE_DECL_SYS_SIGLIST
 541   if (n >= 0 && n < NSIG && sys_siglist[n] != 0)
 542     return sys_siglist[n];
 543 # endif
 544 #endif
 545   sprintf(buf, "Signal %d", n);
 546   return buf;
 547 }