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 <QElapsedTimer>
  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         d.startProcess(cmd, path, lpath, how == DontWait);
 256         if (how == DontWait && d.state == SystemcallPrivate::Running)
 257                 return 0;
 258
 259         if (d.state == SystemcallPrivate::Error
 260                         || !d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 261                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 262                 LYXERR0("error " << d.errorMessage());
 263                 return 10;
 264         }
 265
 266         if (!d.waitWhile(SystemcallPrivate::Running, process_events,
 267                          os::timeout_min() * 60 * 1000)) {
 268                 LYXERR0("Systemcall: '" << cmd << "' did not finish!");
 269                 LYXERR0("error " << d.errorMessage());
 270                 LYXERR0("status " << d.exitStatusMessage());
 271                 return 20;
 272         }
 273
 274         int const exit_code = d.exitCode();
 275         if (exit_code) {
 276                 LYXERR0("Systemcall: '" << cmd << "' finished with exit code " << exit_code);
 277         }
 278
 279         return exit_code;
 280 }
 281
 282
 283 SystemcallPrivate::SystemcallPrivate(std::string const & sf, std::string const & of,
 284                                      std::string const & ef)
 285         : state(Error), process_(new QProcess), out_index_(0), err_index_(0),
 286           in_file_(sf), out_file_(of), err_file_(ef), process_events_(false)
 287 {
 288         if (!in_file_.empty())
 289                 process_->setStandardInputFile(QString::fromLocal8Bit(in_file_.c_str()));
 290         if (!out_file_.empty()) {
 291                 if (out_file_[0] == '&') {
 292                         if (subst(out_file_, " ", "") == "&2"
 293                             && err_file_[0] != '&') {
 294                                 out_file_ = err_file_;
 295                                 process_->setProcessChannelMode(
 296                                                 QProcess::MergedChannels);
 297                         } else {
 298                                 if (err_file_[0] == '&') {
 299                                         // Leave alone things such as
 300                                         // "1>&2 2>&1". Should not be harmful,
 301                                         // but let's give anyway a warning.
 302                                         LYXERR0("Unsupported stdout/stderr redirect.");
 303                                         err_file_.erase();
 304                                 } else {
 305                                         LYXERR0("Ambiguous stdout redirect: "
 306                                                 << out_file_);
 307                                 }
 308                                 out_file_ = os::nulldev();
 309                         }
 310                 }
 311                 // Check whether we have to set the output file.
 312                 if (out_file_ != os::nulldev()) {
 313                         process_->setStandardOutputFile(QString::fromLocal8Bit(
 314                                                         out_file_.c_str()));
 315                 }
 316         }
 317         if (!err_file_.empty()) {
 318                 if (err_file_[0] == '&') {
 319                         if (subst(err_file_, " ", "") == "&1"
 320                             && out_file_[0] != '&') {
 321                                 process_->setProcessChannelMode(
 322                                                 QProcess::MergedChannels);
 323                         } else {
 324                                 LYXERR0("Ambiguous stderr redirect: "
 325                                         << err_file_);
 326                         }
 327                         // In MergedChannels mode stderr goes to stdout.
 328                         err_file_ = os::nulldev();
 329                 }
 330                 // Check whether we have to set the error file.
 331                 if (err_file_ != os::nulldev()) {
 332                         process_->setStandardErrorFile(QString::fromLocal8Bit(
 333                                                         err_file_.c_str()));
 334                 }
 335         }
 336
 337         connect(process_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 338         connect(process_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 339 #if QT_VERSION >= 0x050600
 340         connect(process_, SIGNAL(errorOccurred(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 341 #else
 342         connect(process_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 343 #endif
 344         connect(process_, SIGNAL(started()), this, SLOT(processStarted()));
 345         connect(process_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 346 }
 347
 348
 349 void SystemcallPrivate::startProcess(QString const & cmd, string const & path,
 350                                      string const & lpath, bool detached)
 351 {
 352         cmd_ = cmd;
 353 #if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
 354         // FIXME pass command and arguments separated in the first place
 355         /* The versions of startDetached() and start() that accept a
 356          * QStringList object exist since Qt4, but it is only in Qt 5.15
 357          * that splitCommand() was introduced and the plain versions of
 358          * start/startDetached() have been deprecated.
 359          * The cleanest solution would be to have parsecmd() produce a
 360          * QStringList for arguments, instead of transforming the string
 361          * into something that the QProcess splitter accepts.
 362         */
 363         QStringList arguments = QProcess::splitCommand(toqstr(latexEnvCmdPrefix(path, lpath)) + cmd_);
 364         QString command = (arguments.empty()) ? QString() : arguments.first();
 365         if (arguments.size() == 1)
 366                 arguments.clear();
 367         else if (!arguments.empty())
 368                 arguments.removeFirst();
 369 #endif
 370         if (detached) {
 371                 state = SystemcallPrivate::Running;
 372 #ifdef Q_OS_WIN32
 373                 // Avoid opening a console window when a viewer is started
 374                 if (in_file_.empty())
 375                         process_->setStandardInputFile(QProcess::nullDevice());
 376                 if (out_file_.empty())
 377                         process_->setStandardOutputFile(QProcess::nullDevice());
 378                 if (err_file_.empty())
 379                         process_->setStandardErrorFile(QProcess::nullDevice());
 380 #endif
 381 #if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
 382                 if (!QProcess::startDetached(command, arguments)) {
 383 #else
 384                 if (!QProcess::startDetached(toqstr(latexEnvCmdPrefix(path, lpath)) + cmd_)) {
 385 #endif
 386                         state = SystemcallPrivate::Error;
 387                         return;
 388                 }
 389                 QProcess* released = releaseProcess();
 390                 delete released;
 391         } else if (process_) {
 392                 state = SystemcallPrivate::Starting;
 393 #if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
 394                 process_->start(command, arguments);
 395 #else
 396                 process_->start(toqstr(latexEnvCmdPrefix(path, lpath)) + cmd_);
 397 #endif
 398         }
 399 }
 400
 401
 402 void SystemcallPrivate::processEvents()
 403 {
 404         if (process_events_) {
 405                 QCoreApplication::processEvents(/*QEventLoop::ExcludeUserInputEvents*/);
 406         }
 407 }
 408
 409
 410 void SystemcallPrivate::waitAndProcessEvents()
 411 {
 412         Sleep::millisec(100);
 413         processEvents();
 414 }
 415
 416
 417 namespace {
 418
 419 bool queryStopCommand(QString const & cmd)
 420 {
 421         docstring text = bformat(_(
 422                 "The command\n%1$s\nhas not yet completed.\n\n"
 423                 "Do you want to stop it?"), qstring_to_ucs4(cmd));
 424         return ProgressInterface::instance()->prompt(_("Stop command?"), text,
 425                         1, 1, _("&Stop it"), _("Let it &run")) == 0;
 426 }
 427
 428 } // namespace
 429
 430
 431 bool SystemcallPrivate::waitWhile(State waitwhile, bool process_events, int timeout)
 432 {
 433         if (!process_)
 434                 return false;
 435
 436         bool timedout = false;
 437         process_events_ = process_events;
 438
 439         // Block GUI while waiting,
 440         // relay on QProcess' wait functions
 441         if (!process_events_) {
 442                 if (waitwhile == Starting)
 443                         return process_->waitForStarted(timeout);
 444                 if (waitwhile == Running) {
 445                         int bump = 2;
 446                         while (!timedout) {
 447                                 if (process_->waitForFinished(timeout))
 448                                         return true;
 449                                 bool stop = queryStopCommand(cmd_);
 450                                 // The command may have finished in the meantime
 451                                 if (process_->state() == QProcess::NotRunning)
 452                                         return true;
 453                                 if (stop) {
 454                                         timedout = true;
 455                                         process_->kill();
 456                                 } else {
 457                                         timeout *= bump;
 458                                         bump = 3;
 459                                 }
 460                         }
 461                 }
 462                 return false;
 463         }
 464
 465         // process events while waiting, no timeout
 466         if (timeout == -1) {
 467                 while (state == waitwhile && state != Error) {
 468                         waitAndProcessEvents();
 469                 }
 470                 return state != Error;
 471         }
 472
 473         // process events while waiting with timeout
 474         QElapsedTimer timer;
 475         timer.start();
 476         while (state == waitwhile && state != Error && !timedout) {
 477                 waitAndProcessEvents();
 478                 if (timer.elapsed() > timeout) {
 479                         bool stop = queryStopCommand(cmd_);
 480                         // The command may have finished in the meantime
 481                         if (process_->state() == QProcess::NotRunning)
 482                                 break;
 483                         if (stop) {
 484                                 timedout = true;
 485                                 process_->kill();
 486                         } else
 487                                 timeout *= 3;
 488                 }
 489         }
 490         return (state != Error) && !timedout;
 491 }
 492
 493
 494 SystemcallPrivate::~SystemcallPrivate()
 495 {
 496         if (out_index_) {
 497                 out_data_[out_index_] = '\0';
 498                 out_index_ = 0;
 499                 cout << out_data_;
 500         }
 501         cout.flush();
 502         if (err_index_) {
 503                 err_data_[err_index_] = '\0';
 504                 err_index_ = 0;
 505                 cerr << err_data_;
 506         }
 507         cerr.flush();
 508
 509         killProcess();
 510 }
 511
 512
 513 void SystemcallPrivate::stdOut()
 514 {
 515         if (process_) {
 516                 char c;
 517                 process_->setReadChannel(QProcess::StandardOutput);
 518                 while (process_->getChar(&c)) {
 519                         out_data_[out_index_++] = c;
 520                         if (c == '\n' || out_index_ + 1 == buffer_size_) {
 521                                 out_data_[out_index_] = '\0';
 522                                 out_index_ = 0;
 523                                 ProgressInterface::instance()->appendMessage(QString::fromLocal8Bit(out_data_));
 524                                 cout << out_data_;
 525                         }
 526                 }
 527         }
 528 }
 529
 530
 531 void SystemcallPrivate::stdErr()
 532 {
 533         if (process_) {
 534                 char c;
 535                 process_->setReadChannel(QProcess::StandardError);
 536                 while (process_->getChar(&c)) {
 537                         err_data_[err_index_++] = c;
 538                         if (c == '\n' || err_index_ + 1 == buffer_size_) {
 539                                 err_data_[err_index_] = '\0';
 540                                 err_index_ = 0;
 541                                 ProgressInterface::instance()->appendError(QString::fromLocal8Bit(err_data_));
 542                                 cerr << err_data_;
 543                         }
 544                 }
 545         }
 546 }
 547
 548
 549 void SystemcallPrivate::processStarted()
 550 {
 551         if (state != Running) {
 552                 state = Running;
 553                 ProgressInterface::instance()->processStarted(cmd_);
 554         }
 555 }
 556
 557
 558 void SystemcallPrivate::processFinished(int, QProcess::ExitStatus)
 559 {
 560         if (state != Finished) {
 561                 state = Finished;
 562                 ProgressInterface::instance()->processFinished(cmd_);
 563         }
 564 }
 565
 566
 567 void SystemcallPrivate::processError(QProcess::ProcessError)
 568 {
 569         state = Error;
 570         ProgressInterface::instance()->appendError(errorMessage());
 571 }
 572
 573
 574 QString SystemcallPrivate::errorMessage() const
 575 {
 576         if (!process_)
 577                 return "No QProcess available";
 578
 579         QString message;
 580         switch (process_->error()) {
 581                 case QProcess::FailedToStart:
 582                         message = "The process failed to start. Either the invoked program is missing, "
 583                                       "or you may have insufficient permissions to invoke the program.";
 584                         break;
 585                 case QProcess::Crashed:
 586                         message = "The process crashed some time after starting successfully.";
 587                         break;
 588                 case QProcess::Timedout:
 589                         message = "The process timed out. It might be restarted automatically.";
 590                         break;
 591                 case QProcess::WriteError:
 592                         message = "An error occurred when attempting to write to the process-> For example, "
 593                                       "the process may not be running, or it may have closed its input channel.";
 594                         break;
 595                 case QProcess::ReadError:
 596                         message = "An error occurred when attempting to read from the process-> For example, "
 597                                       "the process may not be running.";
 598                         break;
 599                 case QProcess::UnknownError:
 600                 default:
 601                         message = "An unknown error occurred.";
 602                         break;
 603         }
 604         return message;
 605 }
 606
 607
 608 QString SystemcallPrivate::exitStatusMessage() const
 609 {
 610         if (!process_)
 611                 return "No QProcess available";
 612
 613         QString message;
 614         switch (process_->exitStatus()) {
 615                 case QProcess::NormalExit:
 616                         message = "The process exited normally.";
 617                         break;
 618                 case QProcess::CrashExit:
 619                         message = "The process crashed.";
 620                         break;
 621                 default:
 622                         message = "Unknown exit state.";
 623                         break;
 624         }
 625         return message;
 626 }
 627
 628
 629 int SystemcallPrivate::exitCode()
 630 {
 631         // From Qt's documentation, in regards to QProcess::exitCode(),
 632         // "This value is not valid unless exitStatus() returns NormalExit"
 633         if (!process_ || process_->exitStatus() != QProcess::NormalExit)
 634                 return -1;
 635
 636         return process_->exitCode();
 637 }
 638
 639
 640 QProcess* SystemcallPrivate::releaseProcess()
 641 {
 642         QProcess* released = process_;
 643         process_ = 0;
 644         return released;
 645 }
 646
 647
 648 void SystemcallPrivate::killProcess()
 649 {
 650         killProcess(process_);
 651 }
 652
 653
 654 void SystemcallPrivate::killProcess(QProcess * p)
 655 {
 656         if (p) {
 657                 p->disconnect();
 658                 p->closeReadChannel(QProcess::StandardOutput);
 659                 p->closeReadChannel(QProcess::StandardError);
 660                 p->close();
 661                 delete p;
 662         }
 663 }
 664
 665
 666
 667 #include "moc_SystemcallPrivate.cpp"
 668 #endif
 669
 670 } // namespace support
 671 } // namespace lyx