src/support/Systemcall.cpp

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