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                             string const & path, string const & lpath,
 105                             bool /*process_events*/)
 106 {
 107         string command =
 108                 to_filesystem8bit(from_utf8(latexEnvCmdPrefix(path, lpath)))
 109                        + commandPrep(what);
 110
 111         if (how == DontWait) {
 112                 switch (os::shell()) {
 113                 case os::UNIX:
 114                         command += " &";
 115                         break;
 116                 case os::CMD_EXE:
 117                         command = "start /min " + command;
 118                         break;
 119                 }
 120         } else if (os::shell() == os::CMD_EXE)
 121                 command = subst(command, "cmd /d /c ", "");
 122
 123         return ::system(command.c_str());
 124 }
 125
 126 #else
 127
 128 namespace {
 129
 130 /*
 131  * This is a parser that (mostly) mimics the behavior of a posix shell as
 132  * regards quoting, but its output is tailored for being processed by QProcess.
 133  * Note that shell metacharacters are not parsed.
 134  *
 135  * The escape character is the backslash.
 136  * A backslash that is not quoted preserves the literal value of the following
 137  * character, with the exception of a double-quote '"'. If a double-quote
 138  * follows a backslash, it will be replaced by three consecutive double-quotes
 139  * (this is how the QProcess parser recognizes a '"' as a simple character
 140  * instead of a quoting character). Thus, for example:
 141  *     \\  ->  \
 142  *     \a  ->  a
 143  *     \"  ->  """
 144  *
 145  * Single-quotes.
 146  * Characters enclosed in single-quotes ('') have their literal value preserved.
 147  * A single-quote cannot occur within single-quotes. Indeed, a backslash cannot
 148  * be used to escape a single-quote in a single-quoted string. In other words,
 149  * anything enclosed in single-quotes is passed as is, but the single-quotes
 150  * themselves are eliminated. Thus, for example:
 151  *    '\'    ->  \
 152  *    '\\'   ->  \\
 153  *    '\a'   ->  \a
 154  *    'a\"b' ->  a\"b
 155  *
 156  * Double-quotes.
 157  * Characters enclosed in double-quotes ("") have their literal value preserved,
 158  * with the exception of the backslash. The backslash retains its special
 159  * meaning as an escape character only when followed by a double-quote.
 160  * Contrarily to the behavior of a posix shell, the double-quotes themselves
 161  * are *not* eliminated. Thus, for example:
 162  *    "\\"   ->  "\\"
 163  *    "\a"   ->  "\a"
 164  *    "a\"b" ->  "a"""b"
 165  */
 166 string const parsecmd(string const & incmd, string & infile, string & outfile,
 167                      string & errfile)
 168 {
 169         bool in_single_quote = false;
 170         bool in_double_quote = false;
 171         bool escaped = false;
 172         string const python_call = "python -tt";
 173         vector<string> outcmd(4);
 174         size_t start = 0;
 175
 176         if (prefixIs(incmd, python_call)) {
 177                 outcmd[0] = os::python();
 178                 start = python_call.length();
 179         }
 180
 181         for (size_t i = start, o = 0; i < incmd.length(); ++i) {
 182                 char c = incmd[i];
 183                 if (c == '\'') {
 184                         if (in_double_quote || escaped) {
 185                                 if (in_double_quote && escaped)
 186                                         outcmd[o] += '\\';
 187                                 outcmd[o] += c;
 188                         } else
 189                                 in_single_quote = !in_single_quote;
 190                         escaped = false;
 191                         continue;
 192                 }
 193                 if (in_single_quote) {
 194                         outcmd[o] += c;
 195                         continue;
 196                 }
 197                 if (c == '"') {
 198                         if (escaped) {
 199                                 // Don't triple double-quotes for redirection
 200                                 // files as these won't be parsed by QProcess
 201                                 outcmd[o] += string(o ? "\"" : "\"\"\"");
 202                                 escaped = false;
 203                         } else {
 204                                 outcmd[o] += c;
 205                                 in_double_quote = !in_double_quote;
 206                         }
 207                 } else if (c == '\\' && !escaped) {
 208                         escaped = !escaped;
 209                 } else if (c == '>' && !(in_double_quote || escaped)) {
 210                         if (suffixIs(outcmd[o], " 2")) {
 211                                 outcmd[o] = rtrim(outcmd[o], "2");
 212                                 o = 2;
 213                         } else {
 214                                 if (suffixIs(outcmd[o], " 1"))
 215                                         outcmd[o] = rtrim(outcmd[o], "1");
 216                                 o = 1;
 217                         }
 218                 } else if (c == '<' && !(in_double_quote || escaped)) {
 219                         o = 3;
 220                 } else {
 221                         if (escaped && in_double_quote)
 222                                 outcmd[o] += '\\';
 223                         outcmd[o] += c;
 224                         escaped = false;
 225                 }
 226         }
 227         infile  = trim(outcmd[3], " \"");
 228         outfile = trim(outcmd[1], " \"");
 229         errfile = trim(outcmd[2], " \"");
 230         return trim(outcmd[0]);
 231 }
 232
 233 } // namespace anon
 234
 235
 236
 237 int Systemcall::startscript(Starttype how, string const & what,
 238                             string const & path, string const & lpath,
 239                             bool process_events)
 240 {
 241         string const what_ss = commandPrep(what);
 242         LYXERR(Debug::INFO,"Running: " << what_ss);
 243
 244         string infile;
 245         string outfile;
 246         string errfile;
 247         QString const cmd = QString::fromLocal8Bit(
 248                         parsecmd(what_ss, infile, outfile, errfile).c_str());
 249
 250         SystemcallPrivate d(infile, outfile, errfile);
 251
 252 #ifdef Q_OS_WIN32
 253         // QProcess::startDetached cannot provide environment variables. When the
 254         // environment variables are set using the latexEnvCmdPrefix and the process
 255         // is started with QProcess::startDetached, a console window is shown every
 256         // time a viewer is started. To avoid this, we fall back on Windows to the
 257         // original implementation that creates a QProcess object.
 258         d.startProcess(cmd, path, lpath, false);
 259         if (!d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 260                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 261                 LYXERR0("error " << d.errorMessage());
 262                 return 10;
 263         }
 264         if (how == DontWait) {
 265                 d.releaseProcess();
 266                 return 0;
 267         }
 268 #else
 269         d.startProcess(cmd, path, lpath, how == DontWait);
 270         if (how == DontWait && d.state == SystemcallPrivate::Running)
 271                 return 0;
 272
 273         if (d.state == SystemcallPrivate::Error
 274                         || !d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 275                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 276                 LYXERR0("error " << d.errorMessage());
 277                 return 10;
 278         }
 279 #endif
 280
 281         if (!d.waitWhile(SystemcallPrivate::Running, process_events,
 282                          os::timeout_min() * 60 * 1000)) {
 283                 LYXERR0("Systemcall: '" << cmd << "' did not finish!");
 284                 LYXERR0("error " << d.errorMessage());
 285                 LYXERR0("status " << d.exitStatusMessage());
 286                 return 20;
 287         }
 288
 289         int const exit_code = d.exitCode();
 290         if (exit_code) {
 291                 LYXERR0("Systemcall: '" << cmd << "' finished with exit code " << exit_code);
 292         }
 293
 294         return exit_code;
 295 }
 296
 297
 298 SystemcallPrivate::SystemcallPrivate(std::string const & sf,
 299                                      std::string const & of,
 300                                      std::string const & ef) :
 301                                 process_(new QProcess),
 302                                 out_index_(0),
 303                                 err_index_(0),
 304                                 in_file_(sf),
 305                                 out_file_(of),
 306                                 err_file_(ef),
 307                                 process_events_(false)
 308 {
 309         if (!in_file_.empty())
 310                 process_->setStandardInputFile(QString::fromLocal8Bit(in_file_.c_str()));
 311         if (!out_file_.empty()) {
 312                 if (out_file_[0] == '&') {
 313                         if (subst(out_file_, " ", "") == "&2"
 314                             && err_file_[0] != '&') {
 315                                 out_file_ = err_file_;
 316                                 process_->setProcessChannelMode(
 317                                                 QProcess::MergedChannels);
 318                         } else {
 319                                 if (err_file_[0] == '&') {
 320                                         // Leave alone things such as
 321                                         // "1>&2 2>&1". Should not be harmful,
 322                                         // but let's give anyway a warning.
 323                                         LYXERR0("Unsupported stdout/stderr redirect.");
 324                                         err_file_.erase();
 325                                 } else {
 326                                         LYXERR0("Ambiguous stdout redirect: "
 327                                                 << out_file_);
 328                                 }
 329                                 out_file_ = os::nulldev();
 330                         }
 331                 }
 332                 // Check whether we have to set the output file.
 333                 if (out_file_ != os::nulldev()) {
 334                         process_->setStandardOutputFile(QString::fromLocal8Bit(
 335                                                         out_file_.c_str()));
 336                 }
 337         }
 338         if (!err_file_.empty()) {
 339                 if (err_file_[0] == '&') {
 340                         if (subst(err_file_, " ", "") == "&1"
 341                             && out_file_[0] != '&') {
 342                                 process_->setProcessChannelMode(
 343                                                 QProcess::MergedChannels);
 344                         } else {
 345                                 LYXERR0("Ambiguous stderr redirect: "
 346                                         << err_file_);
 347                         }
 348                         // In MergedChannels mode stderr goes to stdout.
 349                         err_file_ = os::nulldev();
 350                 }
 351                 // Check whether we have to set the error file.
 352                 if (err_file_ != os::nulldev()) {
 353                         process_->setStandardErrorFile(QString::fromLocal8Bit(
 354                                                         err_file_.c_str()));
 355                 }
 356         }
 357
 358         connect(process_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 359         connect(process_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 360         connect(process_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 361         connect(process_, SIGNAL(started()), this, SLOT(processStarted()));
 362         connect(process_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 363 }
 364
 365
 366 void SystemcallPrivate::startProcess(QString const & cmd, string const & path,
 367                                      string const & lpath, bool detached)
 368 {
 369         cmd_ = cmd;
 370         if (detached) {
 371                 state = SystemcallPrivate::Running;
 372                 if (!QProcess::startDetached(toqstr(latexEnvCmdPrefix(path, lpath)) + 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, lpath)) + 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 occurred.";
 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         // From Qt's documentation, in regards to QProcess::exitCode(),
 615         // "This value is not valid unless exitStatus() returns NormalExit"
 616         if (!process_ || process_->exitStatus() != QProcess::NormalExit)
 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