src/support/Systemcall.cpp

   1 /**
   2  * \file Systemcall.cpp
   3  * This file is part of LyX, the document processor.
   4  * Licence details can be found in the file COPYING.
   5  *
   6  * \author Asger Alstrup
   7  * \author Angus Leeming
   8  * \author Enrico Forestieri
   9  * \author Peter Kuemmel
  10  *
  11  * Full author contact details are available in file CREDITS.
  12  */
  13
  14 #include <config.h>
  15
  16 #include "support/debug.h"
  17 #include "support/filetools.h"
  18 #include "support/gettext.h"
  19 #include "support/lstrings.h"
  20 #include "support/qstring_helpers.h"
  21 #include "support/Systemcall.h"
  22 #include "support/SystemcallPrivate.h"
  23 #include "support/os.h"
  24 #include "support/ProgressInterface.h"
  25
  26 #include "LyX.h"
  27
  28 #include <cstdlib>
  29 #include <iostream>
  30
  31 #include <QProcess>
  32 #include <QTime>
  33 #include <QThread>
  34 #include <QCoreApplication>
  35 #include <QDebug>
  36
  37 #define USE_QPROCESS
  38
  39
  40 struct Sleep : QThread
  41 {
  42         static void millisec(unsigned long ms)
  43         {
  44                 QThread::usleep(ms * 1000);
  45         }
  46 };
  47
  48
  49
  50
  51 using namespace std;
  52
  53 namespace lyx {
  54 namespace support {
  55
  56
  57 class ProgressDummy : public ProgressInterface
  58 {
  59 public:
  60         ProgressDummy() {}
  61
  62         void processStarted(QString const &) {}
  63         void processFinished(QString const &) {}
  64         void appendMessage(QString const &) {}
  65         void appendError(QString const &) {}
  66         void clearMessages() {}
  67         void lyxerrFlush() {}
  68
  69         void lyxerrConnect() {}
  70         void lyxerrDisconnect() {}
  71
  72         void warning(QString const &, QString const &) {}
  73         void toggleWarning(QString const &, QString const &, QString const &) {}
  74         void error(QString const &, QString const &, QString const &) {}
  75         void information(QString const &, QString const &) {}
  76         int prompt(docstring const &, docstring const &, int default_but, int,
  77                    docstring const &, docstring const &) { return default_but; }
  78 };
  79
  80
  81 static ProgressInterface * progress_instance = 0;
  82
  83 void ProgressInterface::setInstance(ProgressInterface* p)
  84 {
  85         progress_instance = p;
  86 }
  87
  88
  89 ProgressInterface * ProgressInterface::instance()
  90 {
  91         if (!progress_instance) {
  92                 static ProgressDummy dummy;
  93                 return &dummy;
  94         }
  95         return progress_instance;
  96 }
  97
  98
  99
 100
 101 // Reuse of instance
 102 #ifndef USE_QPROCESS
 103 int Systemcall::startscript(Starttype how, string const & what,
 104                             string const & path, string const & lpath,
 105                             bool /*process_events*/)
 106 {
 107         string command =
 108                 to_filesystem8bit(from_utf8(latexEnvCmdPrefix(path, lpath)))
 109                        + commandPrep(what);
 110
 111         if (how == DontWait) {
 112                 switch (os::shell()) {
 113                 case os::UNIX:
 114                         command += " &";
 115                         break;
 116                 case os::CMD_EXE:
 117                         command = "start /min " + command;
 118                         break;
 119                 }
 120         } else if (os::shell() == os::CMD_EXE)
 121                 command = subst(command, "cmd /d /c ", "");
 122
 123         return ::system(command.c_str());
 124 }
 125
 126 #else
 127
 128 namespace {
 129
 130 /*
 131  * This is a parser that (mostly) mimics the behavior of a posix shell as
 132  * regards quoting, but its output is tailored for being processed by QProcess.
 133  * Note that shell metacharacters are not parsed.
 134  *
 135  * The escape character is the backslash.
 136  * A backslash that is not quoted preserves the literal value of the following
 137  * character, with the exception of a double-quote '"'. If a double-quote
 138  * follows a backslash, it will be replaced by three consecutive double-quotes
 139  * (this is how the QProcess parser recognizes a '"' as a simple character
 140  * instead of a quoting character). Thus, for example:
 141  *     \\  ->  \
 142  *     \a  ->  a
 143  *     \"  ->  """
 144  *
 145  * Single-quotes.
 146  * Characters enclosed in single-quotes ('') have their literal value preserved.
 147  * A single-quote cannot occur within single-quotes. Indeed, a backslash cannot
 148  * be used to escape a single-quote in a single-quoted string. In other words,
 149  * anything enclosed in single-quotes is passed as is, but the single-quotes
 150  * themselves are eliminated. Thus, for example:
 151  *    '\'    ->  \
 152  *    '\\'   ->  \\
 153  *    '\a'   ->  \a
 154  *    'a\"b' ->  a\"b
 155  *
 156  * Double-quotes.
 157  * Characters enclosed in double-quotes ("") have their literal value preserved,
 158  * with the exception of the backslash. The backslash retains its special
 159  * meaning as an escape character only when followed by a double-quote.
 160  * Contrarily to the behavior of a posix shell, the double-quotes themselves
 161  * are *not* eliminated. Thus, for example:
 162  *    "\\"   ->  "\\"
 163  *    "\a"   ->  "\a"
 164  *    "a\"b" ->  "a"""b"
 165  */
 166 string const parsecmd(string const & incmd, string & infile, string & outfile,
 167                      string & errfile)
 168 {
 169         bool in_single_quote = false;
 170         bool in_double_quote = false;
 171         bool escaped = false;
 172         string const python_call = "python -tt";
 173         vector<string> outcmd(4);
 174         size_t start = 0;
 175
 176         if (prefixIs(incmd, python_call)) {
 177                 outcmd[0] = os::python();
 178                 start = python_call.length();
 179         }
 180
 181         for (size_t i = start, o = 0; i < incmd.length(); ++i) {
 182                 char c = incmd[i];
 183                 if (c == '\'') {
 184                         if (in_double_quote || escaped) {
 185                                 if (in_double_quote && escaped)
 186                                         outcmd[o] += '\\';
 187                                 outcmd[o] += c;
 188                         } else
 189                                 in_single_quote = !in_single_quote;
 190                         escaped = false;
 191                         continue;
 192                 }
 193                 if (in_single_quote) {
 194                         outcmd[o] += c;
 195                         continue;
 196                 }
 197                 if (c == '"') {
 198                         if (escaped) {
 199                                 // Don't triple double-quotes for redirection
 200                                 // files as these won't be parsed by QProcess
 201                                 outcmd[o] += string(o ? "\"" : "\"\"\"");
 202                                 escaped = false;
 203                         } else {
 204                                 outcmd[o] += c;
 205                                 in_double_quote = !in_double_quote;
 206                         }
 207                 } else if (c == '\\' && !escaped) {
 208                         escaped = !escaped;
 209                 } else if (c == '>' && !(in_double_quote || escaped)) {
 210                         if (suffixIs(outcmd[o], " 2")) {
 211                                 outcmd[o] = rtrim(outcmd[o], "2");
 212                                 o = 2;
 213                         } else {
 214                                 if (suffixIs(outcmd[o], " 1"))
 215                                         outcmd[o] = rtrim(outcmd[o], "1");
 216                                 o = 1;
 217                         }
 218                 } else if (c == '<' && !(in_double_quote || escaped)) {
 219                         o = 3;
 220                 } else {
 221                         if (escaped && in_double_quote)
 222                                 outcmd[o] += '\\';
 223                         outcmd[o] += c;
 224                         escaped = false;
 225                 }
 226         }
 227         infile  = trim(outcmd[3], " \"");
 228         outfile = trim(outcmd[1], " \"");
 229         errfile = trim(outcmd[2], " \"");
 230         return trim(outcmd[0]);
 231 }
 232
 233 } // namespace
 234
 235
 236 void Systemcall::killscript()
 237 {
 238         SystemcallPrivate::kill_script = true;
 239 }
 240
 241
 242 int Systemcall::startscript(Starttype how, string const & what,
 243                             string const & path, string const & lpath,
 244                             bool process_events)
 245 {
 246         string const what_ss = commandPrep(what);
 247         if (verbose)
 248                 lyxerr << "\nRunning: " << what_ss << endl;
 249         else
 250                 LYXERR(Debug::INFO,"Running: " << what_ss);
 251
 252         string infile;
 253         string outfile;
 254         string errfile;
 255         QString const cmd = QString::fromLocal8Bit(
 256                         parsecmd(what_ss, infile, outfile, errfile).c_str());
 257
 258         SystemcallPrivate d(infile, outfile, errfile);
 259         bool do_events = process_events || how == WaitLoop;
 260
 261 #ifdef Q_OS_WIN32
 262         // QProcess::startDetached cannot provide environment variables. When the
 263         // environment variables are set using the latexEnvCmdPrefix and the process
 264         // is started with QProcess::startDetached, a console window is shown every
 265         // time a viewer is started. To avoid this, we fall back on Windows to the
 266         // original implementation that creates a QProcess object.
 267         d.startProcess(cmd, path, lpath, false);
 268         if (!d.waitWhile(SystemcallPrivate::Starting, do_events, -1)) {
 269                 if (d.state == SystemcallPrivate::Error) {
 270                         LYXERR0("Systemcall: '" << cmd << "' did not start!");
 271                         LYXERR0("error " << d.errorMessage());
 272                         return NOSTART;
 273                 } else if (d.state == SystemcallPrivate::Killed) {
 274                         LYXERR0("Killed: " << cmd);
 275                         return KILLED;
 276                 }
 277         }
 278         if (how == DontWait) {
 279                 d.releaseProcess();
 280                 return OK;
 281         }
 282 #else
 283         d.startProcess(cmd, path, lpath, how == DontWait);
 284         if (how == DontWait && d.state == SystemcallPrivate::Running)
 285                 return OK;
 286
 287         if (d.state == SystemcallPrivate::Error
 288                         || !d.waitWhile(SystemcallPrivate::Starting, do_events, -1)) {
 289                 if (d.state == SystemcallPrivate::Error) {
 290                         LYXERR0("Systemcall: '" << cmd << "' did not start!");
 291                         LYXERR0("error " << d.errorMessage());
 292                         return NOSTART;
 293                 } else if (d.state == SystemcallPrivate::Killed) {
 294                         LYXERR0("Killed: " << cmd);
 295                         return KILLED;
 296                 }
 297         }
 298 #endif
 299
 300         if (!d.waitWhile(SystemcallPrivate::Running, do_events,
 301                          os::timeout_min() * 60 * 1000)) {
 302                 if (d.state == SystemcallPrivate::Killed) {
 303                         LYXERR0("Killed: " << cmd);
 304                         return KILLED;
 305                 }
 306                 LYXERR0("Systemcall: '" << cmd << "' did not finish!");
 307                 LYXERR0("error " << d.errorMessage());
 308                 LYXERR0("status " << d.exitStatusMessage());
 309                 return TIMEOUT;
 310         }
 311
 312         int const exit_code = d.exitCode();
 313         if (exit_code) {
 314                 LYXERR0("Systemcall: '" << cmd << "' finished with exit code " << exit_code);
 315         }
 316
 317         return exit_code;
 318 }
 319
 320
 321 bool SystemcallPrivate::kill_script = false;
 322
 323
 324 SystemcallPrivate::SystemcallPrivate(std::string const & sf, std::string const & of,
 325                                      std::string const & ef)
 326         : state(Error), process_(new QProcess), out_index_(0), err_index_(0),
 327           in_file_(sf), out_file_(of), err_file_(ef), process_events_(false)
 328 {
 329         if (!in_file_.empty())
 330                 process_->setStandardInputFile(QString::fromLocal8Bit(in_file_.c_str()));
 331         if (!out_file_.empty()) {
 332                 if (out_file_[0] == '&') {
 333                         if (subst(out_file_, " ", "") == "&2"
 334                             && err_file_[0] != '&') {
 335                                 out_file_ = err_file_;
 336                                 process_->setProcessChannelMode(
 337                                                 QProcess::MergedChannels);
 338                         } else {
 339                                 if (err_file_[0] == '&') {
 340                                         // Leave alone things such as
 341                                         // "1>&2 2>&1". Should not be harmful,
 342                                         // but let's give anyway a warning.
 343                                         LYXERR0("Unsupported stdout/stderr redirect.");
 344                                         err_file_.erase();
 345                                 } else {
 346                                         LYXERR0("Ambiguous stdout redirect: "
 347                                                 << out_file_);
 348                                 }
 349                                 out_file_ = os::nulldev();
 350                         }
 351                 }
 352                 // Check whether we have to set the output file.
 353                 if (out_file_ != os::nulldev()) {
 354                         process_->setStandardOutputFile(QString::fromLocal8Bit(
 355                                                         out_file_.c_str()));
 356                 }
 357         }
 358         if (!err_file_.empty()) {
 359                 if (err_file_[0] == '&') {
 360                         if (subst(err_file_, " ", "") == "&1"
 361                             && out_file_[0] != '&') {
 362                                 process_->setProcessChannelMode(
 363                                                 QProcess::MergedChannels);
 364                         } else {
 365                                 LYXERR0("Ambiguous stderr redirect: "
 366                                         << err_file_);
 367                         }
 368                         // In MergedChannels mode stderr goes to stdout.
 369                         err_file_ = os::nulldev();
 370                 }
 371                 // Check whether we have to set the error file.
 372                 if (err_file_ != os::nulldev()) {
 373                         process_->setStandardErrorFile(QString::fromLocal8Bit(
 374                                                         err_file_.c_str()));
 375                 }
 376         }
 377
 378         connect(process_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 379         connect(process_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 380 #if QT_VERSION >= 0x050600
 381         connect(process_, SIGNAL(errorOccurred(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 382 #else
 383         connect(process_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 384 #endif
 385         connect(process_, SIGNAL(started()), this, SLOT(processStarted()));
 386         connect(process_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 387 }
 388
 389
 390 void SystemcallPrivate::startProcess(QString const & cmd, string const & path,
 391                                      string const & lpath, bool detached)
 392 {
 393         cmd_ = cmd;
 394         if (detached) {
 395                 state = SystemcallPrivate::Running;
 396                 if (!QProcess::startDetached(toqstr(latexEnvCmdPrefix(path, lpath)) + cmd_)) {
 397                         state = SystemcallPrivate::Error;
 398                         return;
 399                 }
 400                 QProcess* released = releaseProcess();
 401                 delete released;
 402         } else if (process_) {
 403                 state = SystemcallPrivate::Starting;
 404                 process_->start(toqstr(latexEnvCmdPrefix(path, lpath)) + cmd_);
 405         }
 406 }
 407
 408
 409 bool SystemcallPrivate::waitAndCheck()
 410 {
 411         Sleep::millisec(100);
 412         if (kill_script) {
 413                 // is there a better place to reset this?
 414                 process_->kill();
 415                 state = Killed;
 416                 kill_script = false;
 417                 LYXERR0("Export Canceled!!");
 418                 return false;
 419         }
 420         QCoreApplication::processEvents(/*QEventLoop::ExcludeUserInputEvents*/);
 421         return true;
 422 }
 423
 424
 425 namespace {
 426
 427 bool queryStopCommand(QString const & cmd)
 428 {
 429         docstring text = bformat(_(
 430                 "The command\n%1$s\nhas not yet completed.\n\n"
 431                 "Do you want to stop it?"), qstring_to_ucs4(cmd));
 432         return ProgressInterface::instance()->prompt(_("Stop command?"), text,
 433                         1, 1, _("&Stop it"), _("Let it &run")) == 0;
 434 }
 435
 436 } // namespace
 437
 438
 439 bool SystemcallPrivate::waitWhile(State waitwhile, bool process_events, int timeout)
 440 {
 441         if (!process_)
 442                 return false;
 443
 444         bool timedout = false;
 445         process_events_ = process_events;
 446
 447         // Block GUI while waiting,
 448         // relay on QProcess' wait functions
 449         if (!process_events_) {
 450                 if (waitwhile == Starting)
 451                         return process_->waitForStarted(timeout);
 452                 if (waitwhile == Running) {
 453                         int bump = 2;
 454                         while (!timedout) {
 455                                 if (process_->waitForFinished(timeout))
 456                                         return true;
 457                                 bool stop = queryStopCommand(cmd_);
 458                                 // The command may have finished in the meantime
 459                                 if (process_->state() == QProcess::NotRunning)
 460                                         return true;
 461                                 if (stop) {
 462                                         timedout = true;
 463                                         process_->kill();
 464                                 } else {
 465                                         timeout *= bump;
 466                                         bump = 3;
 467                                 }
 468                         }
 469                 }
 470                 return false;
 471         }
 472
 473         // process events while waiting, no timeout
 474         if (timeout == -1) {
 475                 while (state == waitwhile && state != Error) {
 476                         // check for cancellation of background process
 477                         if (!waitAndCheck())
 478                                 return false;
 479                 }
 480                 return state != Error;
 481         }
 482
 483         // process events while waiting with timeout
 484         QTime timer;
 485         timer.start();
 486         while (state == waitwhile && state != Error && !timedout) {
 487                 // check for cancellation of background process
 488                 if (!waitAndCheck())
 489                         return false;
 490
 491                 if (timer.elapsed() > timeout) {
 492                         bool stop = queryStopCommand(cmd_);
 493                         // The command may have finished in the meantime
 494                         if (process_->state() == QProcess::NotRunning)
 495                                 break;
 496                         if (stop) {
 497                                 timedout = true;
 498                                 process_->kill();
 499                         } else
 500                                 timeout *= 3;
 501                 }
 502         }
 503         return (state != Error) && !timedout;
 504 }
 505
 506
 507 SystemcallPrivate::~SystemcallPrivate()
 508 {
 509         if (out_index_) {
 510                 out_data_[out_index_] = '\0';
 511                 out_index_ = 0;
 512                 cout << out_data_;
 513         }
 514         cout.flush();
 515         if (err_index_) {
 516                 err_data_[err_index_] = '\0';
 517                 err_index_ = 0;
 518                 cerr << err_data_;
 519         }
 520         cerr.flush();
 521
 522         killProcess();
 523 }
 524
 525
 526 void SystemcallPrivate::stdOut()
 527 {
 528         if (process_) {
 529                 char c;
 530                 process_->setReadChannel(QProcess::StandardOutput);
 531                 while (process_->getChar(&c)) {
 532                         out_data_[out_index_++] = c;
 533                         if (c == '\n' || out_index_ + 1 == buffer_size_) {
 534                                 out_data_[out_index_] = '\0';
 535                                 out_index_ = 0;
 536                                 ProgressInterface::instance()->appendMessage(QString::fromLocal8Bit(out_data_));
 537                                 cout << out_data_;
 538                         }
 539                 }
 540         }
 541 }
 542
 543
 544 void SystemcallPrivate::stdErr()
 545 {
 546         if (process_) {
 547                 char c;
 548                 process_->setReadChannel(QProcess::StandardError);
 549                 while (process_->getChar(&c)) {
 550                         err_data_[err_index_++] = c;
 551                         if (c == '\n' || err_index_ + 1 == buffer_size_) {
 552                                 err_data_[err_index_] = '\0';
 553                                 err_index_ = 0;
 554                                 ProgressInterface::instance()->appendError(QString::fromLocal8Bit(err_data_));
 555                                 cerr << err_data_;
 556                         }
 557                 }
 558         }
 559 }
 560
 561
 562 void SystemcallPrivate::processStarted()
 563 {
 564         if (state != Running) {
 565                 state = Running;
 566                 ProgressInterface::instance()->processStarted(cmd_);
 567         }
 568 }
 569
 570
 571 void SystemcallPrivate::processFinished(int, QProcess::ExitStatus)
 572 {
 573         if (state != Finished) {
 574                 state = Finished;
 575                 ProgressInterface::instance()->processFinished(cmd_);
 576         }
 577 }
 578
 579
 580 void SystemcallPrivate::processError(QProcess::ProcessError)
 581 {
 582         state = Error;
 583         ProgressInterface::instance()->appendError(errorMessage());
 584 }
 585
 586
 587 QString SystemcallPrivate::errorMessage() const
 588 {
 589         if (!process_)
 590                 return "No QProcess available";
 591
 592         QString message;
 593         switch (process_->error()) {
 594                 case QProcess::FailedToStart:
 595                         message = "The process failed to start. Either the invoked program is missing, "
 596                                       "or you may have insufficient permissions to invoke the program.";
 597                         break;
 598                 case QProcess::Crashed:
 599                         message = "The process crashed some time after starting successfully.";
 600                         break;
 601                 case QProcess::Timedout:
 602                         message = "The process timed out. It might be restarted automatically.";
 603                         break;
 604                 case QProcess::WriteError:
 605                         message = "An error occurred when attempting to write to the process-> For example, "
 606                                       "the process may not be running, or it may have closed its input channel.";
 607                         break;
 608                 case QProcess::ReadError:
 609                         message = "An error occurred when attempting to read from the process-> For example, "
 610                                       "the process may not be running.";
 611                         break;
 612                 case QProcess::UnknownError:
 613                 default:
 614                         message = "An unknown error occurred.";
 615                         break;
 616         }
 617         return message;
 618 }
 619
 620
 621 QString SystemcallPrivate::exitStatusMessage() const
 622 {
 623         if (!process_)
 624                 return "No QProcess available";
 625
 626         QString message;
 627         switch (process_->exitStatus()) {
 628                 case QProcess::NormalExit:
 629                         message = "The process exited normally.";
 630                         break;
 631                 case QProcess::CrashExit:
 632                         message = "The process crashed.";
 633                         break;
 634                 default:
 635                         message = "Unknown exit state.";
 636                         break;
 637         }
 638         return message;
 639 }
 640
 641
 642 int SystemcallPrivate::exitCode()
 643 {
 644         // From Qt's documentation, in regards to QProcess::exitCode(),
 645         // "This value is not valid unless exitStatus() returns NormalExit"
 646         if (!process_ || process_->exitStatus() != QProcess::NormalExit)
 647                 return -1;
 648
 649         return process_->exitCode();
 650 }
 651
 652
 653 QProcess* SystemcallPrivate::releaseProcess()
 654 {
 655         QProcess* released = process_;
 656         process_ = 0;
 657         return released;
 658 }
 659
 660
 661 void SystemcallPrivate::killProcess()
 662 {
 663         killProcess(process_);
 664 }
 665
 666
 667 void SystemcallPrivate::killProcess(QProcess * p)
 668 {
 669         if (p) {
 670                 p->disconnect();
 671                 p->closeReadChannel(QProcess::StandardOutput);
 672                 p->closeReadChannel(QProcess::StandardError);
 673                 p->close();
 674                 delete p;
 675         }
 676 }
 677
 678
 679
 680 #include "moc_SystemcallPrivate.cpp"
 681 #endif
 682
 683 } // namespace support
 684 } // namespace lyx