src/support/Systemcall.cpp

   1 /**
   2  * \file Systemcall.cpp
   3  * This file is part of LyX, the document processor.
   4  * Licence details can be found in the file COPYING.
   5  *
   6  * \author Asger Alstrup
   7  * \author Angus Leeming
   8  * \author Enrico Forestieri
   9  * \author Peter Kuemmel
  10  *
  11  * Full author contact details are available in file CREDITS.
  12  */
  13
  14 #include <config.h>
  15
  16 #include "support/debug.h"
  17 #include "support/filetools.h"
  18 #include "support/gettext.h"
  19 #include "support/lstrings.h"
  20 #include "support/qstring_helpers.h"
  21 #include "support/Systemcall.h"
  22 #include "support/SystemcallPrivate.h"
  23 #include "support/os.h"
  24 #include "support/ProgressInterface.h"
  25
  26 #include "LyXRC.h"
  27
  28 #include <cstdlib>
  29 #include <iostream>
  30
  31 #include <QProcess>
  32 #include <QTime>
  33 #include <QThread>
  34 #include <QCoreApplication>
  35 #include <QDebug>
  36
  37 #define USE_QPROCESS
  38
  39
  40 struct Sleep : QThread
  41 {
  42         static void millisec(unsigned long ms)
  43         {
  44                 QThread::usleep(ms * 1000);
  45         }
  46 };
  47
  48
  49
  50
  51 using namespace std;
  52
  53 namespace lyx {
  54 namespace support {
  55
  56
  57 class ProgressDummy : public ProgressInterface
  58 {
  59 public:
  60         ProgressDummy() {}
  61
  62         void processStarted(QString const &) {}
  63         void processFinished(QString const &) {}
  64         void appendMessage(QString const &) {}
  65         void appendError(QString const &) {}
  66         void clearMessages() {}
  67         void lyxerrFlush() {}
  68
  69         void lyxerrConnect() {}
  70         void lyxerrDisconnect() {}
  71
  72         void warning(QString const &, QString const &) {}
  73         void toggleWarning(QString const &, QString const &, QString const &) {}
  74         void error(QString const &, QString const &, QString const &) {}
  75         void information(QString const &, QString const &) {}
  76         int prompt(docstring const &, docstring const &, int default_but, int,
  77                    docstring const &, docstring const &) { return default_but; }
  78 };
  79
  80
  81 static ProgressInterface * progress_instance = 0;
  82
  83 void ProgressInterface::setInstance(ProgressInterface* p)
  84 {
  85         progress_instance = p;
  86 }
  87
  88
  89 ProgressInterface * ProgressInterface::instance()
  90 {
  91         if (!progress_instance) {
  92                 static ProgressDummy dummy;
  93                 return &dummy;
  94         }
  95         return progress_instance;
  96 }
  97
  98
  99
 100
 101 // Reuse of instance
 102 #ifndef USE_QPROCESS
 103 int Systemcall::startscript(Starttype how, string const & what,
 104                             std::string const & path, bool /*process_events*/)
 105 {
 106         string command = to_filesystem8bit(from_utf8(latexEnvCmdPrefix(path)))
 107                        + commandPrep(what);
 108
 109         if (how == DontWait) {
 110                 switch (os::shell()) {
 111                 case os::UNIX:
 112                         command += " &";
 113                         break;
 114                 case os::CMD_EXE:
 115                         command = "start /min " + command;
 116                         break;
 117                 }
 118         } else if (os::shell() == os::CMD_EXE)
 119                 command = subst(command, "cmd /d /c ", "");
 120
 121         return ::system(command.c_str());
 122 }
 123
 124 #else
 125
 126 namespace {
 127
 128 /*
 129  * This is a parser that (mostly) mimics the behavior of a posix shell as
 130  * regards quoting, but its output is tailored for being processed by QProcess.
 131  * Note that shell metacharacters are not parsed.
 132  *
 133  * The escape character is the backslash.
 134  * A backslash that is not quoted preserves the literal value of the following
 135  * character, with the exception of a double-quote '"'. If a double-quote
 136  * follows a backslash, it will be replaced by three consecutive double-quotes
 137  * (this is how the QProcess parser recognizes a '"' as a simple character
 138  * instead of a quoting character). Thus, for example:
 139  *     \\  ->  \
 140  *     \a  ->  a
 141  *     \"  ->  """
 142  *
 143  * Single-quotes.
 144  * Characters enclosed in single-quotes ('') have their literal value preserved.
 145  * A single-quote cannot occur within single-quotes. Indeed, a backslash cannot
 146  * be used to escape a single-quote in a single-quoted string. In other words,
 147  * anything enclosed in single-quotes is passed as is, but the single-quotes
 148  * themselves are eliminated. Thus, for example:
 149  *    '\'    ->  \
 150  *    '\\'   ->  \\
 151  *    '\a'   ->  \a
 152  *    'a\"b' ->  a\"b
 153  *
 154  * Double-quotes.
 155  * Characters enclosed in double-quotes ("") have their literal value preserved,
 156  * with the exception of the backslash. The backslash retains its special
 157  * meaning as an escape character only when followed by a double-quote.
 158  * Contrarily to the behavior of a posix shell, the double-quotes themselves
 159  * are *not* eliminated. Thus, for example:
 160  *    "\\"   ->  "\\"
 161  *    "\a"   ->  "\a"
 162  *    "a\"b" ->  "a"""b"
 163  */
 164 string const parsecmd(string const & incmd, string & infile, string & outfile,
 165                      string & errfile)
 166 {
 167         bool in_single_quote = false;
 168         bool in_double_quote = false;
 169         bool escaped = false;
 170         string const python_call = "python -tt";
 171         vector<string> outcmd(4);
 172         size_t start = 0;
 173
 174         if (prefixIs(incmd, python_call)) {
 175                 outcmd[0] = os::python();
 176                 start = python_call.length();
 177         }
 178
 179         for (size_t i = start, o = 0; i < incmd.length(); ++i) {
 180                 char c = incmd[i];
 181                 if (c == '\'') {
 182                         if (in_double_quote || escaped) {
 183                                 if (in_double_quote && escaped)
 184                                         outcmd[o] += '\\';
 185                                 outcmd[o] += c;
 186                         } else
 187                                 in_single_quote = !in_single_quote;
 188                         escaped = false;
 189                         continue;
 190                 }
 191                 if (in_single_quote) {
 192                         outcmd[o] += c;
 193                         continue;
 194                 }
 195                 if (c == '"') {
 196                         if (escaped) {
 197                                 // Don't triple double-quotes for redirection
 198                                 // files as these won't be parsed by QProcess
 199                                 outcmd[o] += string(o ? "\"" : "\"\"\"");
 200                                 escaped = false;
 201                         } else {
 202                                 outcmd[o] += c;
 203                                 in_double_quote = !in_double_quote;
 204                         }
 205                 } else if (c == '\\' && !escaped) {
 206                         escaped = !escaped;
 207                 } else if (c == '>' && !(in_double_quote || escaped)) {
 208                         if (suffixIs(outcmd[o], " 2")) {
 209                                 outcmd[o] = rtrim(outcmd[o], "2");
 210                                 o = 2;
 211                         } else {
 212                                 if (suffixIs(outcmd[o], " 1"))
 213                                         outcmd[o] = rtrim(outcmd[o], "1");
 214                                 o = 1;
 215                         }
 216                 } else if (c == '<' && !(in_double_quote || escaped)) {
 217                         o = 3;
 218                 } else {
 219                         if (escaped && in_double_quote)
 220                                 outcmd[o] += '\\';
 221                         outcmd[o] += c;
 222                         escaped = false;
 223                 }
 224         }
 225         infile  = trim(outcmd[3], " \"");
 226         outfile = trim(outcmd[1], " \"");
 227         errfile = trim(outcmd[2], " \"");
 228         return trim(outcmd[0]);
 229 }
 230
 231 } // namespace anon
 232
 233
 234
 235 int Systemcall::startscript(Starttype how, string const & what,
 236                             string const & path, bool process_events)
 237 {
 238         string const what_ss = commandPrep(what);
 239         LYXERR(Debug::INFO,"Running: " << what_ss);
 240
 241         string infile;
 242         string outfile;
 243         string errfile;
 244         QString const cmd = QString::fromLocal8Bit(
 245                         parsecmd(what_ss, infile, outfile, errfile).c_str());
 246
 247         SystemcallPrivate d(infile, outfile, errfile);
 248
 249 #ifdef Q_OS_WIN32
 250         // QProcess::startDetached cannot provide environment variables. When the
 251         // environment variables are set using the latexEnvCmdPrefix and the process
 252         // is started with QProcess::startDetached, a console window is shown every
 253         // time a viewer is started. To avoid this, we fall back on Windows to the
 254         // original implementation that creates a QProcess object.
 255         d.startProcess(cmd, path, false);
 256         if (!d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 257                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 258                 LYXERR0("error " << d.errorMessage());
 259                 return 10;
 260         }
 261         if (how == DontWait) {
 262                 d.releaseProcess();
 263                 return 0;
 264         }
 265 #else
 266         d.startProcess(cmd, path, how == DontWait);
 267         if (how == DontWait && d.state == SystemcallPrivate::Running)
 268                 return 0;
 269
 270         if (d.state == SystemcallPrivate::Error
 271                         || !d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 272                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 273                 LYXERR0("error " << d.errorMessage());
 274                 return 10;
 275         }
 276 #endif
 277
 278         if (!d.waitWhile(SystemcallPrivate::Running, process_events,
 279                          os::timeout_min() * 60 * 1000)) {
 280                 LYXERR0("Systemcall: '" << cmd << "' did not finish!");
 281                 LYXERR0("error " << d.errorMessage());
 282                 LYXERR0("status " << d.exitStatusMessage());
 283                 return 20;
 284         }
 285
 286         int const exit_code = d.exitCode();
 287         if (exit_code) {
 288                 LYXERR0("Systemcall: '" << cmd << "' finished with exit code " << exit_code);
 289         }
 290
 291         return exit_code;
 292 }
 293
 294
 295 SystemcallPrivate::SystemcallPrivate(std::string const & sf,
 296                                      std::string const & of,
 297                                      std::string const & ef) :
 298                                 process_(new QProcess),
 299                                 out_index_(0),
 300                                 err_index_(0),
 301                                 in_file_(sf),
 302                                 out_file_(of),
 303                                 err_file_(ef),
 304                                 process_events_(false)
 305 {
 306         if (!in_file_.empty())
 307                 process_->setStandardInputFile(QString::fromLocal8Bit(in_file_.c_str()));
 308         if (!out_file_.empty()) {
 309                 if (out_file_[0] == '&') {
 310                         if (subst(out_file_, " ", "") == "&2"
 311                             && err_file_[0] != '&') {
 312                                 out_file_ = err_file_;
 313                                 process_->setProcessChannelMode(
 314                                                 QProcess::MergedChannels);
 315                         } else {
 316                                 if (err_file_[0] == '&') {
 317                                         // Leave alone things such as
 318                                         // "1>&2 2>&1". Should not be harmful,
 319                                         // but let's give anyway a warning.
 320                                         LYXERR0("Unsupported stdout/stderr redirect.");
 321                                         err_file_.erase();
 322                                 } else {
 323                                         LYXERR0("Ambiguous stdout redirect: "
 324                                                 << out_file_);
 325                                 }
 326                                 out_file_ = os::nulldev();
 327                         }
 328                 }
 329                 // Check whether we have to set the output file.
 330                 if (out_file_ != os::nulldev()) {
 331                         process_->setStandardOutputFile(QString::fromLocal8Bit(
 332                                                         out_file_.c_str()));
 333                 }
 334         }
 335         if (!err_file_.empty()) {
 336                 if (err_file_[0] == '&') {
 337                         if (subst(err_file_, " ", "") == "&1"
 338                             && out_file_[0] != '&') {
 339                                 process_->setProcessChannelMode(
 340                                                 QProcess::MergedChannels);
 341                         } else {
 342                                 LYXERR0("Ambiguous stderr redirect: "
 343                                         << err_file_);
 344                         }
 345                         // In MergedChannels mode stderr goes to stdout.
 346                         err_file_ = os::nulldev();
 347                 }
 348                 // Check whether we have to set the error file.
 349                 if (err_file_ != os::nulldev()) {
 350                         process_->setStandardErrorFile(QString::fromLocal8Bit(
 351                                                         err_file_.c_str()));
 352                 }
 353         }
 354
 355         connect(process_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 356         connect(process_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 357         connect(process_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 358         connect(process_, SIGNAL(started()), this, SLOT(processStarted()));
 359         connect(process_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 360 }
 361
 362
 363 void SystemcallPrivate::startProcess(QString const & cmd, string const & path, bool detached)
 364 {
 365         cmd_ = cmd;
 366         if (detached) {
 367                 state = SystemcallPrivate::Running;
 368                 if (!QProcess::startDetached(toqstr(latexEnvCmdPrefix(path)) + cmd_)) {
 369                         state = SystemcallPrivate::Error;
 370                         return;
 371                 }
 372                 QProcess* released = releaseProcess();
 373                 delete released;
 374         } else if (process_) {
 375                 state = SystemcallPrivate::Starting;
 376                 process_->start(toqstr(latexEnvCmdPrefix(path)) + cmd_);
 377         }
 378 }
 379
 380
 381 void SystemcallPrivate::processEvents()
 382 {
 383         if (process_events_) {
 384                 QCoreApplication::processEvents(/*QEventLoop::ExcludeUserInputEvents*/);
 385         }
 386 }
 387
 388
 389 void SystemcallPrivate::waitAndProcessEvents()
 390 {
 391         Sleep::millisec(100);
 392         processEvents();
 393 }
 394
 395
 396 namespace {
 397
 398 bool queryStopCommand(QString const & cmd)
 399 {
 400         docstring text = bformat(_(
 401                 "The command\n%1$s\nhas not yet completed.\n\n"
 402                 "Do you want to stop it?"), qstring_to_ucs4(cmd));
 403         return ProgressInterface::instance()->prompt(_("Stop command?"), text,
 404                         1, 1, _("&Stop it"), _("Let it &run")) == 0;
 405 }
 406
 407 }
 408
 409
 410 bool SystemcallPrivate::waitWhile(State waitwhile, bool process_events, int timeout)
 411 {
 412         if (!process_)
 413                 return false;
 414
 415         bool timedout = false;
 416         process_events_ = process_events;
 417
 418         // Block GUI while waiting,
 419         // relay on QProcess' wait functions
 420         if (!process_events_) {
 421                 if (waitwhile == Starting)
 422                         return process_->waitForStarted(timeout);
 423                 if (waitwhile == Running) {
 424                         int bump = 2;
 425                         while (!timedout) {
 426                                 if (process_->waitForFinished(timeout))
 427                                         return true;
 428                                 bool stop = queryStopCommand(cmd_);
 429                                 // The command may have finished in the meantime
 430                                 if (process_->state() == QProcess::NotRunning)
 431                                         return true;
 432                                 if (stop) {
 433                                         timedout = true;
 434                                         process_->kill();
 435                                 } else {
 436                                         timeout *= bump;
 437                                         bump = 3;
 438                                 }
 439                         }
 440                 }
 441                 return false;
 442         }
 443
 444         // process events while waiting, no timeout
 445         if (timeout == -1) {
 446                 while (state == waitwhile && state != Error) {
 447                         waitAndProcessEvents();
 448                 }
 449                 return state != Error;
 450         }
 451
 452         // process events while waiting with timeout
 453         QTime timer;
 454         timer.start();
 455         while (state == waitwhile && state != Error && !timedout) {
 456                 waitAndProcessEvents();
 457                 if (timer.elapsed() > timeout) {
 458                         bool stop = queryStopCommand(cmd_);
 459                         // The command may have finished in the meantime
 460                         if (process_->state() == QProcess::NotRunning)
 461                                 break;
 462                         if (stop) {
 463                                 timedout = true;
 464                                 process_->kill();
 465                         } else
 466                                 timeout *= 3;
 467                 }
 468         }
 469         return (state != Error) && !timedout;
 470 }
 471
 472
 473 SystemcallPrivate::~SystemcallPrivate()
 474 {
 475         if (out_index_) {
 476                 out_data_[out_index_] = '\0';
 477                 out_index_ = 0;
 478                 cout << out_data_;
 479         }
 480         cout.flush();
 481         if (err_index_) {
 482                 err_data_[err_index_] = '\0';
 483                 err_index_ = 0;
 484                 cerr << err_data_;
 485         }
 486         cerr.flush();
 487
 488         killProcess();
 489 }
 490
 491
 492 void SystemcallPrivate::stdOut()
 493 {
 494         if (process_) {
 495                 char c;
 496                 process_->setReadChannel(QProcess::StandardOutput);
 497                 while (process_->getChar(&c)) {
 498                         out_data_[out_index_++] = c;
 499                         if (c == '\n' || out_index_ + 1 == buffer_size_) {
 500                                 out_data_[out_index_] = '\0';
 501                                 out_index_ = 0;
 502                                 ProgressInterface::instance()->appendMessage(QString::fromLocal8Bit(out_data_));
 503                                 cout << out_data_;
 504                         }
 505                 }
 506         }
 507 }
 508
 509
 510 void SystemcallPrivate::stdErr()
 511 {
 512         if (process_) {
 513                 char c;
 514                 process_->setReadChannel(QProcess::StandardError);
 515                 while (process_->getChar(&c)) {
 516                         err_data_[err_index_++] = c;
 517                         if (c == '\n' || err_index_ + 1 == buffer_size_) {
 518                                 err_data_[err_index_] = '\0';
 519                                 err_index_ = 0;
 520                                 ProgressInterface::instance()->appendError(QString::fromLocal8Bit(err_data_));
 521                                 cerr << err_data_;
 522                         }
 523                 }
 524         }
 525 }
 526
 527
 528 void SystemcallPrivate::processStarted()
 529 {
 530         if (state != Running) {
 531                 state = Running;
 532                 ProgressInterface::instance()->processStarted(cmd_);
 533         }
 534 }
 535
 536
 537 void SystemcallPrivate::processFinished(int, QProcess::ExitStatus)
 538 {
 539         if (state != Finished) {
 540                 state = Finished;
 541                 ProgressInterface::instance()->processFinished(cmd_);
 542         }
 543 }
 544
 545
 546 void SystemcallPrivate::processError(QProcess::ProcessError)
 547 {
 548         state = Error;
 549         ProgressInterface::instance()->appendError(errorMessage());
 550 }
 551
 552
 553 QString SystemcallPrivate::errorMessage() const
 554 {
 555         if (!process_)
 556                 return "No QProcess available";
 557
 558         QString message;
 559         switch (process_->error()) {
 560                 case QProcess::FailedToStart:
 561                         message = "The process failed to start. Either the invoked program is missing, "
 562                                       "or you may have insufficient permissions to invoke the program.";
 563                         break;
 564                 case QProcess::Crashed:
 565                         message = "The process crashed some time after starting successfully.";
 566                         break;
 567                 case QProcess::Timedout:
 568                         message = "The process timed out. It might be restarted automatically.";
 569                         break;
 570                 case QProcess::WriteError:
 571                         message = "An error occurred when attempting to write to the process-> For example, "
 572                                       "the process may not be running, or it may have closed its input channel.";
 573                         break;
 574                 case QProcess::ReadError:
 575                         message = "An error occurred when attempting to read from the process-> For example, "
 576                                       "the process may not be running.";
 577                         break;
 578                 case QProcess::UnknownError:
 579                 default:
 580                         message = "An unknown error occurred.";
 581                         break;
 582         }
 583         return message;
 584 }
 585
 586
 587 QString SystemcallPrivate::exitStatusMessage() const
 588 {
 589         if (!process_)
 590                 return "No QProcess available";
 591
 592         QString message;
 593         switch (process_->exitStatus()) {
 594                 case QProcess::NormalExit:
 595                         message = "The process exited normally.";
 596                         break;
 597                 case QProcess::CrashExit:
 598                         message = "The process crashed.";
 599                         break;
 600                 default:
 601                         message = "Unknown exit state.";
 602                         break;
 603         }
 604         return message;
 605 }
 606
 607
 608 int SystemcallPrivate::exitCode()
 609 {
 610         // From Qt's documentation, in regards to QProcess::exitCode(),
 611         // "This value is not valid unless exitStatus() returns NormalExit"
 612         if (!process_ || process_->exitStatus() != QProcess::NormalExit)
 613                 return -1;
 614
 615         return process_->exitCode();
 616 }
 617
 618
 619 QProcess* SystemcallPrivate::releaseProcess()
 620 {
 621         QProcess* released = process_;
 622         process_ = 0;
 623         return released;
 624 }
 625
 626
 627 void SystemcallPrivate::killProcess()
 628 {
 629         killProcess(process_);
 630 }
 631
 632
 633 void SystemcallPrivate::killProcess(QProcess * p)
 634 {
 635         if (p) {
 636                 p->disconnect();
 637                 p->closeReadChannel(QProcess::StandardOutput);
 638                 p->closeReadChannel(QProcess::StandardError);
 639                 p->close();
 640                 delete p;
 641         }
 642 }
 643
 644
 645
 646 #include "moc_SystemcallPrivate.cpp"
 647 #endif
 648
 649 } // namespace support
 650 } // namespace lyx