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 &) {}
  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                             std::string const & path, bool /*process_events*/)
 105 {
 106         string const python_call = "python -tt";
 107         string command = to_filesystem8bit(from_utf8(latexEnvCmdPrefix(path)));
 108
 109         if (prefixIs(what, python_call))
 110                 command += os::python() + what.substr(python_call.length());
 111         else
 112                 command += 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 anon
 237
 238
 239
 240 int Systemcall::startscript(Starttype how, string const & what,
 241                             string const & path, bool process_events)
 242 {
 243         LYXERR(Debug::INFO,"Running: " << what);
 244
 245         string infile;
 246         string outfile;
 247         string errfile;
 248         QString const cmd = QString::fromLocal8Bit(
 249                         parsecmd(what, infile, outfile, errfile).c_str());
 250
 251         SystemcallPrivate d(infile, outfile, errfile);
 252
 253 #ifdef Q_OS_WIN32
 254         // QProcess::startDetached cannot provide environment variables. When the
 255         // environment variables are set using the latexEnvCmdPrefix and the process
 256         // is started with QProcess::startDetached, a console window is shown every
 257         // time a viewer is started. To avoid this, we fall back on Windows to the
 258         // original implementation that creates a QProcess object.
 259         d.startProcess(cmd, path, false);
 260         if (!d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 261                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 262                 LYXERR0("error " << d.errorMessage());
 263                 return 10;
 264         }
 265         if (how == DontWait) {
 266                 d.releaseProcess();
 267                 return 0;
 268         }
 269 #else
 270         d.startProcess(cmd, path, how == DontWait);
 271         if (how == DontWait && d.state == SystemcallPrivate::Running)
 272                 return 0;
 273
 274         if (d.state == SystemcallPrivate::Error
 275                         || !d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 276                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 277                 LYXERR0("error " << d.errorMessage());
 278                 return 10;
 279         }
 280 #endif
 281
 282         if (!d.waitWhile(SystemcallPrivate::Running, process_events,
 283                          os::timeout_min() * 60 * 1000)) {
 284                 LYXERR0("Systemcall: '" << cmd << "' did not finish!");
 285                 LYXERR0("error " << d.errorMessage());
 286                 LYXERR0("status " << d.exitStatusMessage());
 287                 return 20;
 288         }
 289
 290         int const exit_code = d.exitCode();
 291         if (exit_code) {
 292                 LYXERR0("Systemcall: '" << cmd << "' finished with exit code " << exit_code);
 293         }
 294
 295         return exit_code;
 296 }
 297
 298
 299 SystemcallPrivate::SystemcallPrivate(std::string const & sf,
 300                                      std::string const & of,
 301                                      std::string const & ef) :
 302                                 process_(new QProcess),
 303                                 out_index_(0),
 304                                 err_index_(0),
 305                                 in_file_(sf),
 306                                 out_file_(of),
 307                                 err_file_(ef),
 308                                 process_events_(false)
 309 {
 310         if (!in_file_.empty())
 311                 process_->setStandardInputFile(QString::fromLocal8Bit(in_file_.c_str()));
 312         if (!out_file_.empty()) {
 313                 if (out_file_[0] == '&') {
 314                         if (subst(out_file_, " ", "") == "&2"
 315                             && err_file_[0] != '&') {
 316                                 out_file_ = err_file_;
 317                                 process_->setProcessChannelMode(
 318                                                 QProcess::MergedChannels);
 319                         } else {
 320                                 if (err_file_[0] == '&') {
 321                                         // Leave alone things such as
 322                                         // "1>&2 2>&1". Should not be harmful,
 323                                         // but let's give anyway a warning.
 324                                         LYXERR0("Unsupported stdout/stderr redirect.");
 325                                         err_file_.erase();
 326                                 } else {
 327                                         LYXERR0("Ambiguous stdout redirect: "
 328                                                 << out_file_);
 329                                 }
 330                                 out_file_ = os::nulldev();
 331                         }
 332                 }
 333                 // Check whether we have to set the output file.
 334                 if (out_file_ != os::nulldev()) {
 335                         process_->setStandardOutputFile(QString::fromLocal8Bit(
 336                                                         out_file_.c_str()));
 337                 }
 338         }
 339         if (!err_file_.empty()) {
 340                 if (err_file_[0] == '&') {
 341                         if (subst(err_file_, " ", "") == "&1"
 342                             && out_file_[0] != '&') {
 343                                 process_->setProcessChannelMode(
 344                                                 QProcess::MergedChannels);
 345                         } else {
 346                                 LYXERR0("Ambiguous stderr redirect: "
 347                                         << err_file_);
 348                         }
 349                         // In MergedChannels mode stderr goes to stdout.
 350                         err_file_ = os::nulldev();
 351                 }
 352                 // Check whether we have to set the error file.
 353                 if (err_file_ != os::nulldev()) {
 354                         process_->setStandardErrorFile(QString::fromLocal8Bit(
 355                                                         err_file_.c_str()));
 356                 }
 357         }
 358
 359         connect(process_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 360         connect(process_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 361         connect(process_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 362         connect(process_, SIGNAL(started()), this, SLOT(processStarted()));
 363         connect(process_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 364 }
 365
 366
 367 void SystemcallPrivate::startProcess(QString const & cmd, string const & path, bool detached)
 368 {
 369         cmd_ = cmd;
 370         if (detached) {
 371                 state = SystemcallPrivate::Running;
 372                 if (!QProcess::startDetached(toqstr(latexEnvCmdPrefix(path)) + cmd_)) {
 373                         state = SystemcallPrivate::Error;
 374                         return;
 375                 }
 376                 QProcess* released = releaseProcess();
 377                 delete released;
 378         } else if (process_) {
 379                 state = SystemcallPrivate::Starting;
 380                 process_->start(toqstr(latexEnvCmdPrefix(path)) + cmd_);
 381         }
 382 }
 383
 384
 385 void SystemcallPrivate::processEvents()
 386 {
 387         if (process_events_) {
 388                 QCoreApplication::processEvents(/*QEventLoop::ExcludeUserInputEvents*/);
 389         }
 390 }
 391
 392
 393 void SystemcallPrivate::waitAndProcessEvents()
 394 {
 395         Sleep::millisec(100);
 396         processEvents();
 397 }
 398
 399
 400 namespace {
 401
 402 bool queryStopCommand(QString const & cmd)
 403 {
 404         docstring text = bformat(_(
 405                 "The command\n%1$s\nhas not yet completed.\n\n"
 406                 "Do you want to stop it?"), qstring_to_ucs4(cmd));
 407         return ProgressInterface::instance()->prompt(_("Stop command?"), text,
 408                         1, 1, _("&Stop it"), _("Let it &run")) == 0;
 409 }
 410
 411 }
 412
 413
 414 bool SystemcallPrivate::waitWhile(State waitwhile, bool process_events, int timeout)
 415 {
 416         if (!process_)
 417                 return false;
 418
 419         bool timedout = false;
 420         process_events_ = process_events;
 421
 422         // Block GUI while waiting,
 423         // relay on QProcess' wait functions
 424         if (!process_events_) {
 425                 if (waitwhile == Starting)
 426                         return process_->waitForStarted(timeout);
 427                 if (waitwhile == Running) {
 428                         int bump = 2;
 429                         while (!timedout) {
 430                                 if (process_->waitForFinished(timeout))
 431                                         return true;
 432                                 bool stop = queryStopCommand(cmd_);
 433                                 // The command may have finished in the meantime
 434                                 if (process_->state() == QProcess::NotRunning)
 435                                         return true;
 436                                 if (stop) {
 437                                         timedout = true;
 438                                         process_->kill();
 439                                 } else {
 440                                         timeout *= bump;
 441                                         bump = 3;
 442                                 }
 443                         }
 444                 }
 445                 return false;
 446         }
 447
 448         // process events while waiting, no timeout
 449         if (timeout == -1) {
 450                 while (state == waitwhile && state != Error) {
 451                         waitAndProcessEvents();
 452                 }
 453                 return state != Error;
 454         }
 455
 456         // process events while waiting with timeout
 457         QTime timer;
 458         timer.start();
 459         while (state == waitwhile && state != Error && !timedout) {
 460                 waitAndProcessEvents();
 461                 if (timer.elapsed() > timeout) {
 462                         bool stop = queryStopCommand(cmd_);
 463                         // The command may have finished in the meantime
 464                         if (process_->state() == QProcess::NotRunning)
 465                                 break;
 466                         if (stop) {
 467                                 timedout = true;
 468                                 process_->kill();
 469                         } else
 470                                 timeout *= 3;
 471                 }
 472         }
 473         return (state != Error) && !timedout;
 474 }
 475
 476
 477 SystemcallPrivate::~SystemcallPrivate()
 478 {
 479         if (out_index_) {
 480                 out_data_[out_index_] = '\0';
 481                 out_index_ = 0;
 482                 cout << out_data_;
 483         }
 484         cout.flush();
 485         if (err_index_) {
 486                 err_data_[err_index_] = '\0';
 487                 err_index_ = 0;
 488                 cerr << err_data_;
 489         }
 490         cerr.flush();
 491
 492         killProcess();
 493 }
 494
 495
 496 void SystemcallPrivate::stdOut()
 497 {
 498         if (process_) {
 499                 char c;
 500                 process_->setReadChannel(QProcess::StandardOutput);
 501                 while (process_->getChar(&c)) {
 502                         out_data_[out_index_++] = c;
 503                         if (c == '\n' || out_index_ + 1 == buffer_size_) {
 504                                 out_data_[out_index_] = '\0';
 505                                 out_index_ = 0;
 506                                 ProgressInterface::instance()->appendMessage(QString::fromLocal8Bit(out_data_));
 507                                 cout << out_data_;
 508                         }
 509                 }
 510         }
 511 }
 512
 513
 514 void SystemcallPrivate::stdErr()
 515 {
 516         if (process_) {
 517                 char c;
 518                 process_->setReadChannel(QProcess::StandardError);
 519                 while (process_->getChar(&c)) {
 520                         err_data_[err_index_++] = c;
 521                         if (c == '\n' || err_index_ + 1 == buffer_size_) {
 522                                 err_data_[err_index_] = '\0';
 523                                 err_index_ = 0;
 524                                 ProgressInterface::instance()->appendError(QString::fromLocal8Bit(err_data_));
 525                                 cerr << err_data_;
 526                         }
 527                 }
 528         }
 529 }
 530
 531
 532 void SystemcallPrivate::processStarted()
 533 {
 534         if (state != Running) {
 535                 state = Running;
 536                 ProgressInterface::instance()->processStarted(cmd_);
 537         }
 538 }
 539
 540
 541 void SystemcallPrivate::processFinished(int, QProcess::ExitStatus)
 542 {
 543         if (state != Finished) {
 544                 state = Finished;
 545                 ProgressInterface::instance()->processFinished(cmd_);
 546         }
 547 }
 548
 549
 550 void SystemcallPrivate::processError(QProcess::ProcessError)
 551 {
 552         state = Error;
 553         ProgressInterface::instance()->appendError(errorMessage());
 554 }
 555
 556
 557 QString SystemcallPrivate::errorMessage() const
 558 {
 559         if (!process_)
 560                 return "No QProcess available";
 561
 562         QString message;
 563         switch (process_->error()) {
 564                 case QProcess::FailedToStart:
 565                         message = "The process failed to start. Either the invoked program is missing, "
 566                                       "or you may have insufficient permissions to invoke the program.";
 567                         break;
 568                 case QProcess::Crashed:
 569                         message = "The process crashed some time after starting successfully.";
 570                         break;
 571                 case QProcess::Timedout:
 572                         message = "The process timed out. It might be restarted automatically.";
 573                         break;
 574                 case QProcess::WriteError:
 575                         message = "An error occurred when attempting to write to the process-> For example, "
 576                                       "the process may not be running, or it may have closed its input channel.";
 577                         break;
 578                 case QProcess::ReadError:
 579                         message = "An error occurred when attempting to read from the process-> For example, "
 580                                       "the process may not be running.";
 581                         break;
 582                 case QProcess::UnknownError:
 583                 default:
 584                         message = "An unknown error occured.";
 585                         break;
 586         }
 587         return message;
 588 }
 589
 590
 591 QString SystemcallPrivate::exitStatusMessage() const
 592 {
 593         if (!process_)
 594                 return "No QProcess available";
 595
 596         QString message;
 597         switch (process_->exitStatus()) {
 598                 case QProcess::NormalExit:
 599                         message = "The process exited normally.";
 600                         break;
 601                 case QProcess::CrashExit:
 602                         message = "The process crashed.";
 603                         break;
 604                 default:
 605                         message = "Unknown exit state.";
 606                         break;
 607         }
 608         return message;
 609 }
 610
 611
 612 int SystemcallPrivate::exitCode()
 613 {
 614         if (!process_)
 615                 return -1;
 616
 617         return process_->exitCode();
 618 }
 619
 620
 621 QProcess* SystemcallPrivate::releaseProcess()
 622 {
 623         QProcess* released = process_;
 624         process_ = 0;
 625         return released;
 626 }
 627
 628
 629 void SystemcallPrivate::killProcess()
 630 {
 631         killProcess(process_);
 632 }
 633
 634
 635 void SystemcallPrivate::killProcess(QProcess * p)
 636 {
 637         if (p) {
 638                 p->disconnect();
 639                 p->closeReadChannel(QProcess::StandardOutput);
 640                 p->closeReadChannel(QProcess::StandardError);
 641                 p->close();
 642                 delete p;
 643         }
 644 }
 645
 646
 647
 648 #include "moc_SystemcallPrivate.cpp"
 649 #endif
 650
 651 } // namespace support
 652 } // namespace lyx