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