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 anon
 235
 236
 237
 238 int Systemcall::startscript(Starttype how, string const & what,
 239                             string const & path, string const & lpath,
 240                             bool process_events)
 241 {
 242         string const what_ss = commandPrep(what);
 243         if (verbose)
 244                 lyxerr << "\nRunning: " << what_ss << endl;
 245         else
 246                 LYXERR(Debug::INFO,"Running: " << what_ss);
 247
 248         string infile;
 249         string outfile;
 250         string errfile;
 251         QString const cmd = QString::fromLocal8Bit(
 252                         parsecmd(what_ss, infile, outfile, errfile).c_str());
 253
 254         SystemcallPrivate d(infile, outfile, errfile);
 255
 256 #ifdef Q_OS_WIN32
 257         // QProcess::startDetached cannot provide environment variables. When the
 258         // environment variables are set using the latexEnvCmdPrefix and the process
 259         // is started with QProcess::startDetached, a console window is shown every
 260         // time a viewer is started. To avoid this, we fall back on Windows to the
 261         // original implementation that creates a QProcess object.
 262         d.startProcess(cmd, path, lpath, false);
 263         if (!d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 264                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 265                 LYXERR0("error " << d.errorMessage());
 266                 return 10;
 267         }
 268         if (how == DontWait) {
 269                 d.releaseProcess();
 270                 return 0;
 271         }
 272 #else
 273         d.startProcess(cmd, path, lpath, how == DontWait);
 274         if (how == DontWait && d.state == SystemcallPrivate::Running)
 275                 return 0;
 276
 277         if (d.state == SystemcallPrivate::Error
 278                         || !d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 279                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 280                 LYXERR0("error " << d.errorMessage());
 281                 return 10;
 282         }
 283 #endif
 284
 285         if (!d.waitWhile(SystemcallPrivate::Running, process_events,
 286                          os::timeout_min() * 60 * 1000)) {
 287                 LYXERR0("Systemcall: '" << cmd << "' did not finish!");
 288                 LYXERR0("error " << d.errorMessage());
 289                 LYXERR0("status " << d.exitStatusMessage());
 290                 return 20;
 291         }
 292
 293         int const exit_code = d.exitCode();
 294         if (exit_code) {
 295                 LYXERR0("Systemcall: '" << cmd << "' finished with exit code " << exit_code);
 296         }
 297
 298         return exit_code;
 299 }
 300
 301
 302 SystemcallPrivate::SystemcallPrivate(std::string const & sf, std::string const & of,
 303                                      std::string const & ef)
 304         : state(Error), process_(new QProcess), out_index_(0), err_index_(0),
 305           in_file_(sf), out_file_(of), err_file_(ef), process_events_(false)
 306 {
 307         if (!in_file_.empty())
 308                 process_->setStandardInputFile(QString::fromLocal8Bit(in_file_.c_str()));
 309         if (!out_file_.empty()) {
 310                 if (out_file_[0] == '&') {
 311                         if (subst(out_file_, " ", "") == "&2"
 312                             && err_file_[0] != '&') {
 313                                 out_file_ = err_file_;
 314                                 process_->setProcessChannelMode(
 315                                                 QProcess::MergedChannels);
 316                         } else {
 317                                 if (err_file_[0] == '&') {
 318                                         // Leave alone things such as
 319                                         // "1>&2 2>&1". Should not be harmful,
 320                                         // but let's give anyway a warning.
 321                                         LYXERR0("Unsupported stdout/stderr redirect.");
 322                                         err_file_.erase();
 323                                 } else {
 324                                         LYXERR0("Ambiguous stdout redirect: "
 325                                                 << out_file_);
 326                                 }
 327                                 out_file_ = os::nulldev();
 328                         }
 329                 }
 330                 // Check whether we have to set the output file.
 331                 if (out_file_ != os::nulldev()) {
 332                         process_->setStandardOutputFile(QString::fromLocal8Bit(
 333                                                         out_file_.c_str()));
 334                 }
 335         }
 336         if (!err_file_.empty()) {
 337                 if (err_file_[0] == '&') {
 338                         if (subst(err_file_, " ", "") == "&1"
 339                             && out_file_[0] != '&') {
 340                                 process_->setProcessChannelMode(
 341                                                 QProcess::MergedChannels);
 342                         } else {
 343                                 LYXERR0("Ambiguous stderr redirect: "
 344                                         << err_file_);
 345                         }
 346                         // In MergedChannels mode stderr goes to stdout.
 347                         err_file_ = os::nulldev();
 348                 }
 349                 // Check whether we have to set the error file.
 350                 if (err_file_ != os::nulldev()) {
 351                         process_->setStandardErrorFile(QString::fromLocal8Bit(
 352                                                         err_file_.c_str()));
 353                 }
 354         }
 355
 356         connect(process_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 357         connect(process_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 358 #if QT_VERSION >= 0x050600
 359         connect(process_, SIGNAL(errorOccurred(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 360 #else
 361         connect(process_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 362 #endif
 363         connect(process_, SIGNAL(started()), this, SLOT(processStarted()));
 364         connect(process_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 365 }
 366
 367
 368 void SystemcallPrivate::startProcess(QString const & cmd, string const & path,
 369                                      string const & lpath, bool detached)
 370 {
 371         cmd_ = cmd;
 372         if (detached) {
 373                 state = SystemcallPrivate::Running;
 374                 if (!QProcess::startDetached(toqstr(latexEnvCmdPrefix(path, lpath)) + cmd_)) {
 375                         state = SystemcallPrivate::Error;
 376                         return;
 377                 }
 378                 QProcess* released = releaseProcess();
 379                 delete released;
 380         } else if (process_) {
 381                 state = SystemcallPrivate::Starting;
 382                 process_->start(toqstr(latexEnvCmdPrefix(path, lpath)) + cmd_);
 383         }
 384 }
 385
 386
 387 void SystemcallPrivate::processEvents()
 388 {
 389         if (process_events_) {
 390                 QCoreApplication::processEvents(/*QEventLoop::ExcludeUserInputEvents*/);
 391         }
 392 }
 393
 394
 395 void SystemcallPrivate::waitAndProcessEvents()
 396 {
 397         Sleep::millisec(100);
 398         processEvents();
 399 }
 400
 401
 402 namespace {
 403
 404 bool queryStopCommand(QString const & cmd)
 405 {
 406         docstring text = bformat(_(
 407                 "The command\n%1$s\nhas not yet completed.\n\n"
 408                 "Do you want to stop it?"), qstring_to_ucs4(cmd));
 409         return ProgressInterface::instance()->prompt(_("Stop command?"), text,
 410                         1, 1, _("&Stop it"), _("Let it &run")) == 0;
 411 }
 412
 413 }
 414
 415
 416 bool SystemcallPrivate::waitWhile(State waitwhile, bool process_events, int timeout)
 417 {
 418         if (!process_)
 419                 return false;
 420
 421         bool timedout = false;
 422         process_events_ = process_events;
 423
 424         // Block GUI while waiting,
 425         // relay on QProcess' wait functions
 426         if (!process_events_) {
 427                 if (waitwhile == Starting)
 428                         return process_->waitForStarted(timeout);
 429                 if (waitwhile == Running) {
 430                         int bump = 2;
 431                         while (!timedout) {
 432                                 if (process_->waitForFinished(timeout))
 433                                         return true;
 434                                 bool stop = queryStopCommand(cmd_);
 435                                 // The command may have finished in the meantime
 436                                 if (process_->state() == QProcess::NotRunning)
 437                                         return true;
 438                                 if (stop) {
 439                                         timedout = true;
 440                                         process_->kill();
 441                                 } else {
 442                                         timeout *= bump;
 443                                         bump = 3;
 444                                 }
 445                         }
 446                 }
 447                 return false;
 448         }
 449
 450         // process events while waiting, no timeout
 451         if (timeout == -1) {
 452                 while (state == waitwhile && state != Error) {
 453                         waitAndProcessEvents();
 454                 }
 455                 return state != Error;
 456         }
 457
 458         // process events while waiting with timeout
 459         QTime timer;
 460         timer.start();
 461         while (state == waitwhile && state != Error && !timedout) {
 462                 waitAndProcessEvents();
 463                 if (timer.elapsed() > timeout) {
 464                         bool stop = queryStopCommand(cmd_);
 465                         // The command may have finished in the meantime
 466                         if (process_->state() == QProcess::NotRunning)
 467                                 break;
 468                         if (stop) {
 469                                 timedout = true;
 470                                 process_->kill();
 471                         } else
 472                                 timeout *= 3;
 473                 }
 474         }
 475         return (state != Error) && !timedout;
 476 }
 477
 478
 479 SystemcallPrivate::~SystemcallPrivate()
 480 {
 481         if (out_index_) {
 482                 out_data_[out_index_] = '\0';
 483                 out_index_ = 0;
 484                 cout << out_data_;
 485         }
 486         cout.flush();
 487         if (err_index_) {
 488                 err_data_[err_index_] = '\0';
 489                 err_index_ = 0;
 490                 cerr << err_data_;
 491         }
 492         cerr.flush();
 493
 494         killProcess();
 495 }
 496
 497
 498 void SystemcallPrivate::stdOut()
 499 {
 500         if (process_) {
 501                 char c;
 502                 process_->setReadChannel(QProcess::StandardOutput);
 503                 while (process_->getChar(&c)) {
 504                         out_data_[out_index_++] = c;
 505                         if (c == '\n' || out_index_ + 1 == buffer_size_) {
 506                                 out_data_[out_index_] = '\0';
 507                                 out_index_ = 0;
 508                                 ProgressInterface::instance()->appendMessage(QString::fromLocal8Bit(out_data_));
 509                                 cout << out_data_;
 510                         }
 511                 }
 512         }
 513 }
 514
 515
 516 void SystemcallPrivate::stdErr()
 517 {
 518         if (process_) {
 519                 char c;
 520                 process_->setReadChannel(QProcess::StandardError);
 521                 while (process_->getChar(&c)) {
 522                         err_data_[err_index_++] = c;
 523                         if (c == '\n' || err_index_ + 1 == buffer_size_) {
 524                                 err_data_[err_index_] = '\0';
 525                                 err_index_ = 0;
 526                                 ProgressInterface::instance()->appendError(QString::fromLocal8Bit(err_data_));
 527                                 cerr << err_data_;
 528                         }
 529                 }
 530         }
 531 }
 532
 533
 534 void SystemcallPrivate::processStarted()
 535 {
 536         if (state != Running) {
 537                 state = Running;
 538                 ProgressInterface::instance()->processStarted(cmd_);
 539         }
 540 }
 541
 542
 543 void SystemcallPrivate::processFinished(int, QProcess::ExitStatus)
 544 {
 545         if (state != Finished) {
 546                 state = Finished;
 547                 ProgressInterface::instance()->processFinished(cmd_);
 548         }
 549 }
 550
 551
 552 void SystemcallPrivate::processError(QProcess::ProcessError)
 553 {
 554         state = Error;
 555         ProgressInterface::instance()->appendError(errorMessage());
 556 }
 557
 558
 559 QString SystemcallPrivate::errorMessage() const
 560 {
 561         if (!process_)
 562                 return "No QProcess available";
 563
 564         QString message;
 565         switch (process_->error()) {
 566                 case QProcess::FailedToStart:
 567                         message = "The process failed to start. Either the invoked program is missing, "
 568                                       "or you may have insufficient permissions to invoke the program.";
 569                         break;
 570                 case QProcess::Crashed:
 571                         message = "The process crashed some time after starting successfully.";
 572                         break;
 573                 case QProcess::Timedout:
 574                         message = "The process timed out. It might be restarted automatically.";
 575                         break;
 576                 case QProcess::WriteError:
 577                         message = "An error occurred when attempting to write to the process-> For example, "
 578                                       "the process may not be running, or it may have closed its input channel.";
 579                         break;
 580                 case QProcess::ReadError:
 581                         message = "An error occurred when attempting to read from the process-> For example, "
 582                                       "the process may not be running.";
 583                         break;
 584                 case QProcess::UnknownError:
 585                 default:
 586                         message = "An unknown error occurred.";
 587                         break;
 588         }
 589         return message;
 590 }
 591
 592
 593 QString SystemcallPrivate::exitStatusMessage() const
 594 {
 595         if (!process_)
 596                 return "No QProcess available";
 597
 598         QString message;
 599         switch (process_->exitStatus()) {
 600                 case QProcess::NormalExit:
 601                         message = "The process exited normally.";
 602                         break;
 603                 case QProcess::CrashExit:
 604                         message = "The process crashed.";
 605                         break;
 606                 default:
 607                         message = "Unknown exit state.";
 608                         break;
 609         }
 610         return message;
 611 }
 612
 613
 614 int SystemcallPrivate::exitCode()
 615 {
 616         // From Qt's documentation, in regards to QProcess::exitCode(),
 617         // "This value is not valid unless exitStatus() returns NormalExit"
 618         if (!process_ || process_->exitStatus() != QProcess::NormalExit)
 619                 return -1;
 620
 621         return process_->exitCode();
 622 }
 623
 624
 625 QProcess* SystemcallPrivate::releaseProcess()
 626 {
 627         QProcess* released = process_;
 628         process_ = 0;
 629         return released;
 630 }
 631
 632
 633 void SystemcallPrivate::killProcess()
 634 {
 635         killProcess(process_);
 636 }
 637
 638
 639 void SystemcallPrivate::killProcess(QProcess * p)
 640 {
 641         if (p) {
 642                 p->disconnect();
 643                 p->closeReadChannel(QProcess::StandardOutput);
 644                 p->closeReadChannel(QProcess::StandardError);
 645                 p->close();
 646                 delete p;
 647         }
 648 }
 649
 650
 651
 652 #include "moc_SystemcallPrivate.cpp"
 653 #endif
 654
 655 } // namespace support
 656 } // namespace lyx