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 "LyXRC.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 anon
 234
 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         LYXERR(Debug::INFO,"Running: " << what_ss);
 243
 244         string infile;
 245         string outfile;
 246         string errfile;
 247         QString const cmd = QString::fromLocal8Bit(
 248                         parsecmd(what_ss, infile, outfile, errfile).c_str());
 249
 250         SystemcallPrivate d(infile, outfile, errfile);
 251
 252 #ifdef Q_OS_WIN32
 253         // QProcess::startDetached cannot provide environment variables. When the
 254         // environment variables are set using the latexEnvCmdPrefix and the process
 255         // is started with QProcess::startDetached, a console window is shown every
 256         // time a viewer is started. To avoid this, we fall back on Windows to the
 257         // original implementation that creates a QProcess object.
 258         d.startProcess(cmd, path, lpath, false);
 259         if (!d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 260                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 261                 LYXERR0("error " << d.errorMessage());
 262                 return 10;
 263         }
 264         if (how == DontWait) {
 265                 d.releaseProcess();
 266                 return 0;
 267         }
 268 #else
 269         d.startProcess(cmd, path, lpath, how == DontWait);
 270         if (how == DontWait && d.state == SystemcallPrivate::Running)
 271                 return 0;
 272
 273         if (d.state == SystemcallPrivate::Error
 274                         || !d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 275                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 276                 LYXERR0("error " << d.errorMessage());
 277                 return 10;
 278         }
 279 #endif
 280
 281         if (!d.waitWhile(SystemcallPrivate::Running, process_events,
 282                          os::timeout_min() * 60 * 1000)) {
 283                 LYXERR0("Systemcall: '" << cmd << "' did not finish!");
 284                 LYXERR0("error " << d.errorMessage());
 285                 LYXERR0("status " << d.exitStatusMessage());
 286                 return 20;
 287         }
 288
 289         int const exit_code = d.exitCode();
 290         if (exit_code) {
 291                 LYXERR0("Systemcall: '" << cmd << "' finished with exit code " << exit_code);
 292         }
 293
 294         return exit_code;
 295 }
 296
 297
 298 SystemcallPrivate::SystemcallPrivate(std::string const & sf,
 299                                      std::string const & of,
 300                                      std::string const & ef) :
 301                                 process_(new QProcess),
 302                                 out_index_(0),
 303                                 err_index_(0),
 304                                 in_file_(sf),
 305                                 out_file_(of),
 306                                 err_file_(ef),
 307                                 process_events_(false)
 308 {
 309         if (!in_file_.empty())
 310                 process_->setStandardInputFile(QString::fromLocal8Bit(in_file_.c_str()));
 311         if (!out_file_.empty()) {
 312                 if (out_file_[0] == '&') {
 313                         if (subst(out_file_, " ", "") == "&2"
 314                             && err_file_[0] != '&') {
 315                                 out_file_ = err_file_;
 316                                 process_->setProcessChannelMode(
 317                                                 QProcess::MergedChannels);
 318                         } else {
 319                                 if (err_file_[0] == '&') {
 320                                         // Leave alone things such as
 321                                         // "1>&2 2>&1". Should not be harmful,
 322                                         // but let's give anyway a warning.
 323                                         LYXERR0("Unsupported stdout/stderr redirect.");
 324                                         err_file_.erase();
 325                                 } else {
 326                                         LYXERR0("Ambiguous stdout redirect: "
 327                                                 << out_file_);
 328                                 }
 329                                 out_file_ = os::nulldev();
 330                         }
 331                 }
 332                 // Check whether we have to set the output file.
 333                 if (out_file_ != os::nulldev()) {
 334                         process_->setStandardOutputFile(QString::fromLocal8Bit(
 335                                                         out_file_.c_str()));
 336                 }
 337         }
 338         if (!err_file_.empty()) {
 339                 if (err_file_[0] == '&') {
 340                         if (subst(err_file_, " ", "") == "&1"
 341                             && out_file_[0] != '&') {
 342                                 process_->setProcessChannelMode(
 343                                                 QProcess::MergedChannels);
 344                         } else {
 345                                 LYXERR0("Ambiguous stderr redirect: "
 346                                         << err_file_);
 347                         }
 348                         // In MergedChannels mode stderr goes to stdout.
 349                         err_file_ = os::nulldev();
 350                 }
 351                 // Check whether we have to set the error file.
 352                 if (err_file_ != os::nulldev()) {
 353                         process_->setStandardErrorFile(QString::fromLocal8Bit(
 354                                                         err_file_.c_str()));
 355                 }
 356         }
 357
 358         connect(process_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 359         connect(process_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 360 #if QT_VERSION >= 0x050600
 361         connect(process_, SIGNAL(errorOccurred(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 362 #else
 363         connect(process_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 364 #endif
 365         connect(process_, SIGNAL(started()), this, SLOT(processStarted()));
 366         connect(process_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 367 }
 368
 369
 370 void SystemcallPrivate::startProcess(QString const & cmd, string const & path,
 371                                      string const & lpath, bool detached)
 372 {
 373         cmd_ = cmd;
 374         if (detached) {
 375                 state = SystemcallPrivate::Running;
 376                 if (!QProcess::startDetached(toqstr(latexEnvCmdPrefix(path, lpath)) + cmd_)) {
 377                         state = SystemcallPrivate::Error;
 378                         return;
 379                 }
 380                 QProcess* released = releaseProcess();
 381                 delete released;
 382         } else if (process_) {
 383                 state = SystemcallPrivate::Starting;
 384                 process_->start(toqstr(latexEnvCmdPrefix(path, lpath)) + cmd_);
 385         }
 386 }
 387
 388
 389 void SystemcallPrivate::processEvents()
 390 {
 391         if (process_events_) {
 392                 QCoreApplication::processEvents(/*QEventLoop::ExcludeUserInputEvents*/);
 393         }
 394 }
 395
 396
 397 void SystemcallPrivate::waitAndProcessEvents()
 398 {
 399         Sleep::millisec(100);
 400         processEvents();
 401 }
 402
 403
 404 namespace {
 405
 406 bool queryStopCommand(QString const & cmd)
 407 {
 408         docstring text = bformat(_(
 409                 "The command\n%1$s\nhas not yet completed.\n\n"
 410                 "Do you want to stop it?"), qstring_to_ucs4(cmd));
 411         return ProgressInterface::instance()->prompt(_("Stop command?"), text,
 412                         1, 1, _("&Stop it"), _("Let it &run")) == 0;
 413 }
 414
 415 }
 416
 417
 418 bool SystemcallPrivate::waitWhile(State waitwhile, bool process_events, int timeout)
 419 {
 420         if (!process_)
 421                 return false;
 422
 423         bool timedout = false;
 424         process_events_ = process_events;
 425
 426         // Block GUI while waiting,
 427         // relay on QProcess' wait functions
 428         if (!process_events_) {
 429                 if (waitwhile == Starting)
 430                         return process_->waitForStarted(timeout);
 431                 if (waitwhile == Running) {
 432                         int bump = 2;
 433                         while (!timedout) {
 434                                 if (process_->waitForFinished(timeout))
 435                                         return true;
 436                                 bool stop = queryStopCommand(cmd_);
 437                                 // The command may have finished in the meantime
 438                                 if (process_->state() == QProcess::NotRunning)
 439                                         return true;
 440                                 if (stop) {
 441                                         timedout = true;
 442                                         process_->kill();
 443                                 } else {
 444                                         timeout *= bump;
 445                                         bump = 3;
 446                                 }
 447                         }
 448                 }
 449                 return false;
 450         }
 451
 452         // process events while waiting, no timeout
 453         if (timeout == -1) {
 454                 while (state == waitwhile && state != Error) {
 455                         waitAndProcessEvents();
 456                 }
 457                 return state != Error;
 458         }
 459
 460         // process events while waiting with timeout
 461         QTime timer;
 462         timer.start();
 463         while (state == waitwhile && state != Error && !timedout) {
 464                 waitAndProcessEvents();
 465                 if (timer.elapsed() > timeout) {
 466                         bool stop = queryStopCommand(cmd_);
 467                         // The command may have finished in the meantime
 468                         if (process_->state() == QProcess::NotRunning)
 469                                 break;
 470                         if (stop) {
 471                                 timedout = true;
 472                                 process_->kill();
 473                         } else
 474                                 timeout *= 3;
 475                 }
 476         }
 477         return (state != Error) && !timedout;
 478 }
 479
 480
 481 SystemcallPrivate::~SystemcallPrivate()
 482 {
 483         if (out_index_) {
 484                 out_data_[out_index_] = '\0';
 485                 out_index_ = 0;
 486                 cout << out_data_;
 487         }
 488         cout.flush();
 489         if (err_index_) {
 490                 err_data_[err_index_] = '\0';
 491                 err_index_ = 0;
 492                 cerr << err_data_;
 493         }
 494         cerr.flush();
 495
 496         killProcess();
 497 }
 498
 499
 500 void SystemcallPrivate::stdOut()
 501 {
 502         if (process_) {
 503                 char c;
 504                 process_->setReadChannel(QProcess::StandardOutput);
 505                 while (process_->getChar(&c)) {
 506                         out_data_[out_index_++] = c;
 507                         if (c == '\n' || out_index_ + 1 == buffer_size_) {
 508                                 out_data_[out_index_] = '\0';
 509                                 out_index_ = 0;
 510                                 ProgressInterface::instance()->appendMessage(QString::fromLocal8Bit(out_data_));
 511                                 cout << out_data_;
 512                         }
 513                 }
 514         }
 515 }
 516
 517
 518 void SystemcallPrivate::stdErr()
 519 {
 520         if (process_) {
 521                 char c;
 522                 process_->setReadChannel(QProcess::StandardError);
 523                 while (process_->getChar(&c)) {
 524                         err_data_[err_index_++] = c;
 525                         if (c == '\n' || err_index_ + 1 == buffer_size_) {
 526                                 err_data_[err_index_] = '\0';
 527                                 err_index_ = 0;
 528                                 ProgressInterface::instance()->appendError(QString::fromLocal8Bit(err_data_));
 529                                 cerr << err_data_;
 530                         }
 531                 }
 532         }
 533 }
 534
 535
 536 void SystemcallPrivate::processStarted()
 537 {
 538         if (state != Running) {
 539                 state = Running;
 540                 ProgressInterface::instance()->processStarted(cmd_);
 541         }
 542 }
 543
 544
 545 void SystemcallPrivate::processFinished(int, QProcess::ExitStatus)
 546 {
 547         if (state != Finished) {
 548                 state = Finished;
 549                 ProgressInterface::instance()->processFinished(cmd_);
 550         }
 551 }
 552
 553
 554 void SystemcallPrivate::processError(QProcess::ProcessError)
 555 {
 556         state = Error;
 557         ProgressInterface::instance()->appendError(errorMessage());
 558 }
 559
 560
 561 QString SystemcallPrivate::errorMessage() const
 562 {
 563         if (!process_)
 564                 return "No QProcess available";
 565
 566         QString message;
 567         switch (process_->error()) {
 568                 case QProcess::FailedToStart:
 569                         message = "The process failed to start. Either the invoked program is missing, "
 570                                       "or you may have insufficient permissions to invoke the program.";
 571                         break;
 572                 case QProcess::Crashed:
 573                         message = "The process crashed some time after starting successfully.";
 574                         break;
 575                 case QProcess::Timedout:
 576                         message = "The process timed out. It might be restarted automatically.";
 577                         break;
 578                 case QProcess::WriteError:
 579                         message = "An error occurred when attempting to write to the process-> For example, "
 580                                       "the process may not be running, or it may have closed its input channel.";
 581                         break;
 582                 case QProcess::ReadError:
 583                         message = "An error occurred when attempting to read from the process-> For example, "
 584                                       "the process may not be running.";
 585                         break;
 586                 case QProcess::UnknownError:
 587                 default:
 588                         message = "An unknown error occurred.";
 589                         break;
 590         }
 591         return message;
 592 }
 593
 594
 595 QString SystemcallPrivate::exitStatusMessage() const
 596 {
 597         if (!process_)
 598                 return "No QProcess available";
 599
 600         QString message;
 601         switch (process_->exitStatus()) {
 602                 case QProcess::NormalExit:
 603                         message = "The process exited normally.";
 604                         break;
 605                 case QProcess::CrashExit:
 606                         message = "The process crashed.";
 607                         break;
 608                 default:
 609                         message = "Unknown exit state.";
 610                         break;
 611         }
 612         return message;
 613 }
 614
 615
 616 int SystemcallPrivate::exitCode()
 617 {
 618         // From Qt's documentation, in regards to QProcess::exitCode(),
 619         // "This value is not valid unless exitStatus() returns NormalExit"
 620         if (!process_ || process_->exitStatus() != QProcess::NormalExit)
 621                 return -1;
 622
 623         return process_->exitCode();
 624 }
 625
 626
 627 QProcess* SystemcallPrivate::releaseProcess()
 628 {
 629         QProcess* released = process_;
 630         process_ = 0;
 631         return released;
 632 }
 633
 634
 635 void SystemcallPrivate::killProcess()
 636 {
 637         killProcess(process_);
 638 }
 639
 640
 641 void SystemcallPrivate::killProcess(QProcess * p)
 642 {
 643         if (p) {
 644                 p->disconnect();
 645                 p->closeReadChannel(QProcess::StandardOutput);
 646                 p->closeReadChannel(QProcess::StandardError);
 647                 p->close();
 648                 delete p;
 649         }
 650 }
 651
 652
 653
 654 #include "moc_SystemcallPrivate.cpp"
 655 #endif
 656
 657 } // namespace support
 658 } // namespace lyx