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, std::string const & of,
 299                                      std::string const & ef)
 300         : state(Error), process_(new QProcess), out_index_(0), err_index_(0),
 301           in_file_(sf), out_file_(of), err_file_(ef), process_events_(false)
 302 {
 303         if (!in_file_.empty())
 304                 process_->setStandardInputFile(QString::fromLocal8Bit(in_file_.c_str()));
 305         if (!out_file_.empty()) {
 306                 if (out_file_[0] == '&') {
 307                         if (subst(out_file_, " ", "") == "&2"
 308                             && err_file_[0] != '&') {
 309                                 out_file_ = err_file_;
 310                                 process_->setProcessChannelMode(
 311                                                 QProcess::MergedChannels);
 312                         } else {
 313                                 if (err_file_[0] == '&') {
 314                                         // Leave alone things such as
 315                                         // "1>&2 2>&1". Should not be harmful,
 316                                         // but let's give anyway a warning.
 317                                         LYXERR0("Unsupported stdout/stderr redirect.");
 318                                         err_file_.erase();
 319                                 } else {
 320                                         LYXERR0("Ambiguous stdout redirect: "
 321                                                 << out_file_);
 322                                 }
 323                                 out_file_ = os::nulldev();
 324                         }
 325                 }
 326                 // Check whether we have to set the output file.
 327                 if (out_file_ != os::nulldev()) {
 328                         process_->setStandardOutputFile(QString::fromLocal8Bit(
 329                                                         out_file_.c_str()));
 330                 }
 331         }
 332         if (!err_file_.empty()) {
 333                 if (err_file_[0] == '&') {
 334                         if (subst(err_file_, " ", "") == "&1"
 335                             && out_file_[0] != '&') {
 336                                 process_->setProcessChannelMode(
 337                                                 QProcess::MergedChannels);
 338                         } else {
 339                                 LYXERR0("Ambiguous stderr redirect: "
 340                                         << err_file_);
 341                         }
 342                         // In MergedChannels mode stderr goes to stdout.
 343                         err_file_ = os::nulldev();
 344                 }
 345                 // Check whether we have to set the error file.
 346                 if (err_file_ != os::nulldev()) {
 347                         process_->setStandardErrorFile(QString::fromLocal8Bit(
 348                                                         err_file_.c_str()));
 349                 }
 350         }
 351
 352         connect(process_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 353         connect(process_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 354 #if QT_VERSION >= 0x050600
 355         connect(process_, SIGNAL(errorOccurred(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 356 #else
 357         connect(process_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 358 #endif
 359         connect(process_, SIGNAL(started()), this, SLOT(processStarted()));
 360         connect(process_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 361 }
 362
 363
 364 void SystemcallPrivate::startProcess(QString const & cmd, string const & path,
 365                                      string const & lpath, bool detached)
 366 {
 367         cmd_ = cmd;
 368         if (detached) {
 369                 state = SystemcallPrivate::Running;
 370                 if (!QProcess::startDetached(toqstr(latexEnvCmdPrefix(path, lpath)) + cmd_)) {
 371                         state = SystemcallPrivate::Error;
 372                         return;
 373                 }
 374                 QProcess* released = releaseProcess();
 375                 delete released;
 376         } else if (process_) {
 377                 state = SystemcallPrivate::Starting;
 378                 process_->start(toqstr(latexEnvCmdPrefix(path, lpath)) + cmd_);
 379         }
 380 }
 381
 382
 383 void SystemcallPrivate::processEvents()
 384 {
 385         if (process_events_) {
 386                 QCoreApplication::processEvents(/*QEventLoop::ExcludeUserInputEvents*/);
 387         }
 388 }
 389
 390
 391 void SystemcallPrivate::waitAndProcessEvents()
 392 {
 393         Sleep::millisec(100);
 394         processEvents();
 395 }
 396
 397
 398 namespace {
 399
 400 bool queryStopCommand(QString const & cmd)
 401 {
 402         docstring text = bformat(_(
 403                 "The command\n%1$s\nhas not yet completed.\n\n"
 404                 "Do you want to stop it?"), qstring_to_ucs4(cmd));
 405         return ProgressInterface::instance()->prompt(_("Stop command?"), text,
 406                         1, 1, _("&Stop it"), _("Let it &run")) == 0;
 407 }
 408
 409 }
 410
 411
 412 bool SystemcallPrivate::waitWhile(State waitwhile, bool process_events, int timeout)
 413 {
 414         if (!process_)
 415                 return false;
 416
 417         bool timedout = false;
 418         process_events_ = process_events;
 419
 420         // Block GUI while waiting,
 421         // relay on QProcess' wait functions
 422         if (!process_events_) {
 423                 if (waitwhile == Starting)
 424                         return process_->waitForStarted(timeout);
 425                 if (waitwhile == Running) {
 426                         int bump = 2;
 427                         while (!timedout) {
 428                                 if (process_->waitForFinished(timeout))
 429                                         return true;
 430                                 bool stop = queryStopCommand(cmd_);
 431                                 // The command may have finished in the meantime
 432                                 if (process_->state() == QProcess::NotRunning)
 433                                         return true;
 434                                 if (stop) {
 435                                         timedout = true;
 436                                         process_->kill();
 437                                 } else {
 438                                         timeout *= bump;
 439                                         bump = 3;
 440                                 }
 441                         }
 442                 }
 443                 return false;
 444         }
 445
 446         // process events while waiting, no timeout
 447         if (timeout == -1) {
 448                 while (state == waitwhile && state != Error) {
 449                         waitAndProcessEvents();
 450                 }
 451                 return state != Error;
 452         }
 453
 454         // process events while waiting with timeout
 455         QTime timer;
 456         timer.start();
 457         while (state == waitwhile && state != Error && !timedout) {
 458                 waitAndProcessEvents();
 459                 if (timer.elapsed() > timeout) {
 460                         bool stop = queryStopCommand(cmd_);
 461                         // The command may have finished in the meantime
 462                         if (process_->state() == QProcess::NotRunning)
 463                                 break;
 464                         if (stop) {
 465                                 timedout = true;
 466                                 process_->kill();
 467                         } else
 468                                 timeout *= 3;
 469                 }
 470         }
 471         return (state != Error) && !timedout;
 472 }
 473
 474
 475 SystemcallPrivate::~SystemcallPrivate()
 476 {
 477         if (out_index_) {
 478                 out_data_[out_index_] = '\0';
 479                 out_index_ = 0;
 480                 cout << out_data_;
 481         }
 482         cout.flush();
 483         if (err_index_) {
 484                 err_data_[err_index_] = '\0';
 485                 err_index_ = 0;
 486                 cerr << err_data_;
 487         }
 488         cerr.flush();
 489
 490         killProcess();
 491 }
 492
 493
 494 void SystemcallPrivate::stdOut()
 495 {
 496         if (process_) {
 497                 char c;
 498                 process_->setReadChannel(QProcess::StandardOutput);
 499                 while (process_->getChar(&c)) {
 500                         out_data_[out_index_++] = c;
 501                         if (c == '\n' || out_index_ + 1 == buffer_size_) {
 502                                 out_data_[out_index_] = '\0';
 503                                 out_index_ = 0;
 504                                 ProgressInterface::instance()->appendMessage(QString::fromLocal8Bit(out_data_));
 505                                 cout << out_data_;
 506                         }
 507                 }
 508         }
 509 }
 510
 511
 512 void SystemcallPrivate::stdErr()
 513 {
 514         if (process_) {
 515                 char c;
 516                 process_->setReadChannel(QProcess::StandardError);
 517                 while (process_->getChar(&c)) {
 518                         err_data_[err_index_++] = c;
 519                         if (c == '\n' || err_index_ + 1 == buffer_size_) {
 520                                 err_data_[err_index_] = '\0';
 521                                 err_index_ = 0;
 522                                 ProgressInterface::instance()->appendError(QString::fromLocal8Bit(err_data_));
 523                                 cerr << err_data_;
 524                         }
 525                 }
 526         }
 527 }
 528
 529
 530 void SystemcallPrivate::processStarted()
 531 {
 532         if (state != Running) {
 533                 state = Running;
 534                 ProgressInterface::instance()->processStarted(cmd_);
 535         }
 536 }
 537
 538
 539 void SystemcallPrivate::processFinished(int, QProcess::ExitStatus)
 540 {
 541         if (state != Finished) {
 542                 state = Finished;
 543                 ProgressInterface::instance()->processFinished(cmd_);
 544         }
 545 }
 546
 547
 548 void SystemcallPrivate::processError(QProcess::ProcessError)
 549 {
 550         state = Error;
 551         ProgressInterface::instance()->appendError(errorMessage());
 552 }
 553
 554
 555 QString SystemcallPrivate::errorMessage() const
 556 {
 557         if (!process_)
 558                 return "No QProcess available";
 559
 560         QString message;
 561         switch (process_->error()) {
 562                 case QProcess::FailedToStart:
 563                         message = "The process failed to start. Either the invoked program is missing, "
 564                                       "or you may have insufficient permissions to invoke the program.";
 565                         break;
 566                 case QProcess::Crashed:
 567                         message = "The process crashed some time after starting successfully.";
 568                         break;
 569                 case QProcess::Timedout:
 570                         message = "The process timed out. It might be restarted automatically.";
 571                         break;
 572                 case QProcess::WriteError:
 573                         message = "An error occurred when attempting to write to the process-> For example, "
 574                                       "the process may not be running, or it may have closed its input channel.";
 575                         break;
 576                 case QProcess::ReadError:
 577                         message = "An error occurred when attempting to read from the process-> For example, "
 578                                       "the process may not be running.";
 579                         break;
 580                 case QProcess::UnknownError:
 581                 default:
 582                         message = "An unknown error occurred.";
 583                         break;
 584         }
 585         return message;
 586 }
 587
 588
 589 QString SystemcallPrivate::exitStatusMessage() const
 590 {
 591         if (!process_)
 592                 return "No QProcess available";
 593
 594         QString message;
 595         switch (process_->exitStatus()) {
 596                 case QProcess::NormalExit:
 597                         message = "The process exited normally.";
 598                         break;
 599                 case QProcess::CrashExit:
 600                         message = "The process crashed.";
 601                         break;
 602                 default:
 603                         message = "Unknown exit state.";
 604                         break;
 605         }
 606         return message;
 607 }
 608
 609
 610 int SystemcallPrivate::exitCode()
 611 {
 612         // From Qt's documentation, in regards to QProcess::exitCode(),
 613         // "This value is not valid unless exitStatus() returns NormalExit"
 614         if (!process_ || process_->exitStatus() != QProcess::NormalExit)
 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