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         string what_ss = libScriptSearch(what);
 109
 110         if (prefixIs(what_ss, python_call))
 111                 command += os::python() + what_ss.substr(python_call.length());
 112         else
 113                 command += what_ss;
 114
 115         if (how == DontWait) {
 116                 switch (os::shell()) {
 117                 case os::UNIX:
 118                         command += " &";
 119                         break;
 120                 case os::CMD_EXE:
 121                         command = "start /min " + command;
 122                         break;
 123                 }
 124         } else if (os::shell() == os::CMD_EXE)
 125                 command = subst(command, "cmd /d /c ", "");
 126
 127         return ::system(command.c_str());
 128 }
 129
 130 #else
 131
 132 namespace {
 133
 134 /*
 135  * This is a parser that (mostly) mimics the behavior of a posix shell as
 136  * regards quoting, but its output is tailored for being processed by QProcess.
 137  * Note that shell metacharacters are not parsed.
 138  *
 139  * The escape character is the backslash.
 140  * A backslash that is not quoted preserves the literal value of the following
 141  * character, with the exception of a double-quote '"'. If a double-quote
 142  * follows a backslash, it will be replaced by three consecutive double-quotes
 143  * (this is how the QProcess parser recognizes a '"' as a simple character
 144  * instead of a quoting character). Thus, for example:
 145  *     \\  ->  \
 146  *     \a  ->  a
 147  *     \"  ->  """
 148  *
 149  * Single-quotes.
 150  * Characters enclosed in single-quotes ('') have their literal value preserved.
 151  * A single-quote cannot occur within single-quotes. Indeed, a backslash cannot
 152  * be used to escape a single-quote in a single-quoted string. In other words,
 153  * anything enclosed in single-quotes is passed as is, but the single-quotes
 154  * themselves are eliminated. Thus, for example:
 155  *    '\'    ->  \
 156  *    '\\'   ->  \\
 157  *    '\a'   ->  \a
 158  *    'a\"b' ->  a\"b
 159  *
 160  * Double-quotes.
 161  * Characters enclosed in double-quotes ("") have their literal value preserved,
 162  * with the exception of the backslash. The backslash retains its special
 163  * meaning as an escape character only when followed by a double-quote.
 164  * Contrarily to the behavior of a posix shell, the double-quotes themselves
 165  * are *not* eliminated. Thus, for example:
 166  *    "\\"   ->  "\\"
 167  *    "\a"   ->  "\a"
 168  *    "a\"b" ->  "a"""b"
 169  */
 170 string const parsecmd(string const & incmd, string & infile, string & outfile,
 171                      string & errfile)
 172 {
 173         bool in_single_quote = false;
 174         bool in_double_quote = false;
 175         bool escaped = false;
 176         string const python_call = "python -tt";
 177         vector<string> outcmd(4);
 178         size_t start = 0;
 179
 180         if (prefixIs(incmd, python_call)) {
 181                 outcmd[0] = os::python();
 182                 start = python_call.length();
 183         }
 184
 185         for (size_t i = start, o = 0; i < incmd.length(); ++i) {
 186                 char c = incmd[i];
 187                 if (c == '\'') {
 188                         if (in_double_quote || escaped) {
 189                                 if (in_double_quote && escaped)
 190                                         outcmd[o] += '\\';
 191                                 outcmd[o] += c;
 192                         } else
 193                                 in_single_quote = !in_single_quote;
 194                         escaped = false;
 195                         continue;
 196                 }
 197                 if (in_single_quote) {
 198                         outcmd[o] += c;
 199                         continue;
 200                 }
 201                 if (c == '"') {
 202                         if (escaped) {
 203                                 // Don't triple double-quotes for redirection
 204                                 // files as these won't be parsed by QProcess
 205                                 outcmd[o] += string(o ? "\"" : "\"\"\"");
 206                                 escaped = false;
 207                         } else {
 208                                 outcmd[o] += c;
 209                                 in_double_quote = !in_double_quote;
 210                         }
 211                 } else if (c == '\\' && !escaped) {
 212                         escaped = !escaped;
 213                 } else if (c == '>' && !(in_double_quote || escaped)) {
 214                         if (suffixIs(outcmd[o], " 2")) {
 215                                 outcmd[o] = rtrim(outcmd[o], "2");
 216                                 o = 2;
 217                         } else {
 218                                 if (suffixIs(outcmd[o], " 1"))
 219                                         outcmd[o] = rtrim(outcmd[o], "1");
 220                                 o = 1;
 221                         }
 222                 } else if (c == '<' && !(in_double_quote || escaped)) {
 223                         o = 3;
 224                 } else {
 225                         if (escaped && in_double_quote)
 226                                 outcmd[o] += '\\';
 227                         outcmd[o] += c;
 228                         escaped = false;
 229                 }
 230         }
 231         infile  = trim(outcmd[3], " \"");
 232         outfile = trim(outcmd[1], " \"");
 233         errfile = trim(outcmd[2], " \"");
 234         return trim(outcmd[0]);
 235 }
 236
 237 } // namespace anon
 238
 239
 240
 241 int Systemcall::startscript(Starttype how, string const & what,
 242                             string const & path, bool process_events)
 243 {
 244         string const what_ss = libScriptSearch(what);
 245         LYXERR(Debug::INFO,"Running: " << what_ss);
 246
 247         string infile;
 248         string outfile;
 249         string errfile;
 250         QString const cmd = QString::fromLocal8Bit(
 251                         parsecmd(what_ss, infile, outfile, errfile).c_str());
 252
 253         SystemcallPrivate d(infile, outfile, errfile);
 254
 255 #ifdef Q_OS_WIN32
 256         // QProcess::startDetached cannot provide environment variables. When the
 257         // environment variables are set using the latexEnvCmdPrefix and the process
 258         // is started with QProcess::startDetached, a console window is shown every
 259         // time a viewer is started. To avoid this, we fall back on Windows to the
 260         // original implementation that creates a QProcess object.
 261         d.startProcess(cmd, path, false);
 262         if (!d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 263                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 264                 LYXERR0("error " << d.errorMessage());
 265                 return 10;
 266         }
 267         if (how == DontWait) {
 268                 d.releaseProcess();
 269                 return 0;
 270         }
 271 #else
 272         d.startProcess(cmd, path, how == DontWait);
 273         if (how == DontWait && d.state == SystemcallPrivate::Running)
 274                 return 0;
 275
 276         if (d.state == SystemcallPrivate::Error
 277                         || !d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 278                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 279                 LYXERR0("error " << d.errorMessage());
 280                 return 10;
 281         }
 282 #endif
 283
 284         if (!d.waitWhile(SystemcallPrivate::Running, process_events,
 285                          os::timeout_min() * 60 * 1000)) {
 286                 LYXERR0("Systemcall: '" << cmd << "' did not finish!");
 287                 LYXERR0("error " << d.errorMessage());
 288                 LYXERR0("status " << d.exitStatusMessage());
 289                 return 20;
 290         }
 291
 292         int const exit_code = d.exitCode();
 293         if (exit_code) {
 294                 LYXERR0("Systemcall: '" << cmd << "' finished with exit code " << exit_code);
 295         }
 296
 297         return exit_code;
 298 }
 299
 300
 301 SystemcallPrivate::SystemcallPrivate(std::string const & sf,
 302                                      std::string const & of,
 303                                      std::string const & ef) :
 304                                 process_(new QProcess),
 305                                 out_index_(0),
 306                                 err_index_(0),
 307                                 in_file_(sf),
 308                                 out_file_(of),
 309                                 err_file_(ef),
 310                                 process_events_(false)
 311 {
 312         if (!in_file_.empty())
 313                 process_->setStandardInputFile(QString::fromLocal8Bit(in_file_.c_str()));
 314         if (!out_file_.empty()) {
 315                 if (out_file_[0] == '&') {
 316                         if (subst(out_file_, " ", "") == "&2"
 317                             && err_file_[0] != '&') {
 318                                 out_file_ = err_file_;
 319                                 process_->setProcessChannelMode(
 320                                                 QProcess::MergedChannels);
 321                         } else {
 322                                 if (err_file_[0] == '&') {
 323                                         // Leave alone things such as
 324                                         // "1>&2 2>&1". Should not be harmful,
 325                                         // but let's give anyway a warning.
 326                                         LYXERR0("Unsupported stdout/stderr redirect.");
 327                                         err_file_.erase();
 328                                 } else {
 329                                         LYXERR0("Ambiguous stdout redirect: "
 330                                                 << out_file_);
 331                                 }
 332                                 out_file_ = os::nulldev();
 333                         }
 334                 }
 335                 // Check whether we have to set the output file.
 336                 if (out_file_ != os::nulldev()) {
 337                         process_->setStandardOutputFile(QString::fromLocal8Bit(
 338                                                         out_file_.c_str()));
 339                 }
 340         }
 341         if (!err_file_.empty()) {
 342                 if (err_file_[0] == '&') {
 343                         if (subst(err_file_, " ", "") == "&1"
 344                             && out_file_[0] != '&') {
 345                                 process_->setProcessChannelMode(
 346                                                 QProcess::MergedChannels);
 347                         } else {
 348                                 LYXERR0("Ambiguous stderr redirect: "
 349                                         << err_file_);
 350                         }
 351                         // In MergedChannels mode stderr goes to stdout.
 352                         err_file_ = os::nulldev();
 353                 }
 354                 // Check whether we have to set the error file.
 355                 if (err_file_ != os::nulldev()) {
 356                         process_->setStandardErrorFile(QString::fromLocal8Bit(
 357                                                         err_file_.c_str()));
 358                 }
 359         }
 360
 361         connect(process_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 362         connect(process_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 363         connect(process_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 364         connect(process_, SIGNAL(started()), this, SLOT(processStarted()));
 365         connect(process_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 366 }
 367
 368
 369 void SystemcallPrivate::startProcess(QString const & cmd, string const & path, bool detached)
 370 {
 371         cmd_ = cmd;
 372         if (detached) {
 373                 state = SystemcallPrivate::Running;
 374                 if (!QProcess::startDetached(toqstr(latexEnvCmdPrefix(path)) + 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)) + 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 occured.";
 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         if (!process_)
 617                 return -1;
 618
 619         return process_->exitCode();
 620 }
 621
 622
 623 QProcess* SystemcallPrivate::releaseProcess()
 624 {
 625         QProcess* released = process_;
 626         process_ = 0;
 627         return released;
 628 }
 629
 630
 631 void SystemcallPrivate::killProcess()
 632 {
 633         killProcess(process_);
 634 }
 635
 636
 637 void SystemcallPrivate::killProcess(QProcess * p)
 638 {
 639         if (p) {
 640                 p->disconnect();
 641                 p->closeReadChannel(QProcess::StandardOutput);
 642                 p->closeReadChannel(QProcess::StandardError);
 643                 p->close();
 644                 delete p;
 645         }
 646 }
 647
 648
 649
 650 #include "moc_SystemcallPrivate.cpp"
 651 #endif
 652
 653 } // namespace support
 654 } // namespace lyx