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