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/lstrings.h"
  19 #include "support/qstring_helpers.h"
  20 #include "support/Systemcall.h"
  21 #include "support/SystemcallPrivate.h"
  22 #include "support/os.h"
  23 #include "support/ProgressInterface.h"
  24
  25 #include "LyXRC.h"
  26
  27 #include <cstdlib>
  28 #include <iostream>
  29
  30 #include <QProcess>
  31 #include <QTime>
  32 #include <QThread>
  33 #include <QCoreApplication>
  34 #include <QDebug>
  35
  36 #define USE_QPROCESS
  37
  38
  39 struct Sleep : QThread
  40 {
  41         static void millisec(unsigned long ms)
  42         {
  43                 QThread::usleep(ms * 1000);
  44         }
  45 };
  46
  47
  48
  49
  50 using namespace std;
  51
  52 namespace lyx {
  53 namespace support {
  54
  55
  56 class ProgressDummy : public ProgressInterface
  57 {
  58 public:
  59         ProgressDummy() {}
  60
  61         void processStarted(QString const &) {}
  62         void processFinished(QString const &) {}
  63         void appendMessage(QString const &) {}
  64         void appendError(QString const &) {}
  65         void clearMessages() {}
  66         void lyxerrFlush() {}
  67
  68         void lyxerrConnect() {}
  69         void lyxerrDisconnect() {}
  70
  71         void warning(QString const &, QString const &) {}
  72         void toggleWarning(QString const &, QString const &, QString const &) {}
  73         void error(QString const &, QString const &) {}
  74         void information(QString const &, QString const &) {}
  75 };
  76
  77
  78 static ProgressInterface* progress_instance = 0;
  79
  80 void ProgressInterface::setInstance(ProgressInterface* p)
  81 {
  82         progress_instance = p;
  83 }
  84
  85
  86 ProgressInterface* ProgressInterface::instance()
  87 {
  88         if (!progress_instance) {
  89                 static ProgressDummy dummy;
  90                 return &dummy;
  91         }
  92         return progress_instance;
  93 }
  94
  95
  96
  97
  98 // Reuse of instance
  99 #ifndef USE_QPROCESS
 100 int Systemcall::startscript(Starttype how, string const & what,
 101                             std::string const & path, bool /*process_events*/)
 102 {
 103         string const python_call = "python -tt";
 104         string command = to_filesystem8bit(from_utf8(latexEnvCmdPrefix(path)));
 105
 106         if (prefixIs(what, python_call))
 107                 command += os::python() + what.substr(python_call.length());
 108         else
 109                 command += 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 but
 132  * its output is tailored for being processed by QProcess.
 133  *
 134  * The escape character is the backslash.
 135  * A backslash that is not quoted preserves the literal value of the following
 136  * character, with the exception of a double-quote '"'. If a double-quote
 137  * follows a backslash, it will be replaced by three consecutive double-quotes
 138  * (this is how the QProcess parser recognizes a '"' as a simple character
 139  * instead of a quoting character). Thus, for example:
 140  *     \\  ->  \
 141  *     \a  ->  a
 142  *     \"  ->  """
 143  *
 144  * Single-quotes.
 145  * Characters enclosed in single-quotes ('') have their literal value preserved.
 146  * A single-quote cannot occur within single-quotes. Indeed, a backslash cannot
 147  * be used to escape a single-quote in a single-quoted string. In other words,
 148  * anything enclosed in single-quotes is passed as is, but the single-quotes
 149  * themselves are eliminated. Thus, for example:
 150  *    '\'    ->  \
 151  *    '\\'   ->  \\
 152  *    '\a'   ->  \a
 153  *    'a\"b' ->  a\"b
 154  *
 155  * Double-quotes.
 156  * Characters enclosed in double-quotes ("") have their literal value preserved,
 157  * with the exception of the backslash. The backslash retains its special
 158  * meaning as an escape character only when followed by a double-quote.
 159  * Contrarily to the behavior of a posix shell, the double-quotes themselves
 160  * are *not* eliminated. Thus, for example:
 161  *    "\\"   ->  "\\"
 162  *    "\a"   ->  "\a"
 163  *    "a\"b" ->  "a"""b"
 164  */
 165 string const parsecmd(string const & inputcmd, string & outfile)
 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         string cmd;
 172         int start = 0;
 173
 174         if (prefixIs(inputcmd, python_call)) {
 175                 cmd = os::python();
 176                 start = python_call.length();
 177         }
 178
 179         for (size_t i = start; i < inputcmd.length(); ++i) {
 180                 char c = inputcmd[i];
 181                 if (c == '\'') {
 182                         if (in_double_quote || escaped) {
 183                                 if (in_double_quote && escaped)
 184                                         cmd += '\\';
 185                                 cmd += c;
 186                         } else
 187                                 in_single_quote = !in_single_quote;
 188                         escaped = false;
 189                         continue;
 190                 }
 191                 if (in_single_quote) {
 192                         cmd += c;
 193                         continue;
 194                 }
 195                 if (c == '"') {
 196                         if (escaped) {
 197                                 cmd += "\"\"\"";
 198                                 escaped = false;
 199                         } else {
 200                                 cmd += c;
 201                                 in_double_quote = !in_double_quote;
 202                         }
 203                 } else if (c == '\\' && !escaped) {
 204                         escaped = !escaped;
 205                 } else if (c == '>' && !(in_double_quote || escaped)) {
 206                         outfile = trim(inputcmd.substr(i + 1), " \"");
 207                         return trim(cmd);
 208                 } else {
 209                         if (escaped && in_double_quote)
 210                                 cmd += '\\';
 211                         cmd += c;
 212                         escaped = false;
 213                 }
 214         }
 215         outfile.erase();
 216         return cmd;
 217 }
 218
 219 } // namespace anon
 220
 221
 222
 223 int Systemcall::startscript(Starttype how, string const & what,
 224                             string const & path, bool process_events)
 225 {
 226         string outfile;
 227         QString cmd = QString::fromLocal8Bit(parsecmd(what, outfile).c_str());
 228
 229         SystemcallPrivate d(outfile);
 230
 231
 232         d.startProcess(cmd, path);
 233         if (!d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 234                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 235                 LYXERR0("error " << d.errorMessage());
 236                 return 10;
 237         }
 238
 239         if (how == DontWait) {
 240                 QProcess* released = d.releaseProcess();
 241                 (void) released; // TODO who deletes it?
 242                 return 0;
 243         }
 244
 245         if (!d.waitWhile(SystemcallPrivate::Running, process_events,
 246                          os::timeout_min() * 60 * 1000)) {
 247                 LYXERR0("Systemcall: '" << cmd << "' did not finish!");
 248                 LYXERR0("error " << d.errorMessage());
 249                 LYXERR0("status " << d.exitStatusMessage());
 250                 return 20;
 251         }
 252
 253         int const exit_code = d.exitCode();
 254         if (exit_code) {
 255                 LYXERR0("Systemcall: '" << cmd << "' finished with exit code " << exit_code);
 256         }
 257
 258         return exit_code;
 259 }
 260
 261
 262 SystemcallPrivate::SystemcallPrivate(const std::string& of) :
 263                                 process_(new QProcess),
 264                                 out_index_(0),
 265                                 err_index_(0),
 266                                 out_file_(of),
 267                                 process_events_(false)
 268 {
 269         if (!out_file_.empty()) {
 270                 // Check whether we have to simply throw away the output.
 271                 if (out_file_ != os::nulldev())
 272                         process_->setStandardOutputFile(QString::fromLocal8Bit(out_file_.c_str()));
 273         }
 274
 275         connect(process_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 276         connect(process_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 277         connect(process_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 278         connect(process_, SIGNAL(started()), this, SLOT(processStarted()));
 279         connect(process_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 280 }
 281
 282
 283 void SystemcallPrivate::startProcess(QString const & cmd, string const & path)
 284 {
 285         cmd_ = cmd;
 286         if (process_) {
 287                 state = SystemcallPrivate::Starting;
 288                 process_->start(toqstr(latexEnvCmdPrefix(path)) + cmd_);
 289         }
 290 }
 291
 292
 293 void SystemcallPrivate::processEvents()
 294 {
 295         if(process_events_) {
 296                 QCoreApplication::processEvents(/*QEventLoop::ExcludeUserInputEvents*/);
 297         }
 298 }
 299
 300
 301 void SystemcallPrivate::waitAndProcessEvents()
 302 {
 303         Sleep::millisec(100);
 304         processEvents();
 305 }
 306
 307
 308 bool SystemcallPrivate::waitWhile(State waitwhile, bool process_events, int timeout)
 309 {
 310         if (!process_)
 311                 return false;
 312
 313         process_events_ = process_events;
 314
 315         // Block GUI while waiting,
 316         // relay on QProcess' wait functions
 317         if (!process_events_) {
 318                 if (waitwhile == Starting)
 319                         return process_->waitForStarted(timeout);
 320                 if (waitwhile == Running)
 321                         return process_->waitForFinished(timeout);
 322                 return false;
 323         }
 324
 325         // process events while waiting, no timeout
 326         if (timeout == -1) {
 327                 while (state == waitwhile && state != Error) {
 328                         waitAndProcessEvents();
 329                 }
 330                 return state != Error;
 331         }
 332
 333         // process events while waiting whith timeout
 334         QTime timer;
 335         timer.start();
 336         while (state == waitwhile && state != Error && timer.elapsed() < timeout) {
 337                 waitAndProcessEvents();
 338         }
 339         return (state != Error) && (timer.elapsed() < timeout);
 340 }
 341
 342
 343 SystemcallPrivate::~SystemcallPrivate()
 344 {
 345         if (out_index_) {
 346                 out_data_[out_index_] = '\0';
 347                 out_index_ = 0;
 348                 cout << out_data_;
 349         }
 350         cout.flush();
 351         if (err_index_) {
 352                 err_data_[err_index_] = '\0';
 353                 err_index_ = 0;
 354                 cerr << err_data_;
 355         }
 356         cerr.flush();
 357
 358         killProcess();
 359 }
 360
 361
 362 void SystemcallPrivate::stdOut()
 363 {
 364         if (process_) {
 365                 char c;
 366                 process_->setReadChannel(QProcess::StandardOutput);
 367                 while (process_->getChar(&c)) {
 368                         out_data_[out_index_++] = c;
 369                         if (c == '\n' || out_index_ + 1 == buffer_size_) {
 370                                 out_data_[out_index_] = '\0';
 371                                 out_index_ = 0;
 372                                 ProgressInterface::instance()->appendMessage(QString::fromLocal8Bit(out_data_));
 373                                 cout << out_data_;
 374                         }
 375                 }
 376         }
 377 }
 378
 379
 380 void SystemcallPrivate::stdErr()
 381 {
 382         if (process_) {
 383                 char c;
 384                 process_->setReadChannel(QProcess::StandardError);
 385                 while (process_->getChar(&c)) {
 386                         err_data_[err_index_++] = c;
 387                         if (c == '\n' || err_index_ + 1 == buffer_size_) {
 388                                 err_data_[err_index_] = '\0';
 389                                 err_index_ = 0;
 390                                 ProgressInterface::instance()->appendError(QString::fromLocal8Bit(err_data_));
 391                                 cerr << err_data_;
 392                         }
 393                 }
 394         }
 395 }
 396
 397
 398 void SystemcallPrivate::processStarted()
 399 {
 400         if (state != Running) {
 401                 state = Running;
 402                 ProgressInterface::instance()->processStarted(cmd_);
 403         }
 404 }
 405
 406
 407 void SystemcallPrivate::processFinished(int, QProcess::ExitStatus)
 408 {
 409         if (state != Finished) {
 410                 state = Finished;
 411                 ProgressInterface::instance()->processFinished(cmd_);
 412         }
 413 }
 414
 415
 416 void SystemcallPrivate::processError(QProcess::ProcessError)
 417 {
 418         state = Error;
 419         ProgressInterface::instance()->appendError(errorMessage());
 420 }
 421
 422
 423 QString SystemcallPrivate::errorMessage() const
 424 {
 425         if (!process_)
 426                 return "No QProcess available";
 427
 428         QString message;
 429         switch (process_->error()) {
 430                 case QProcess::FailedToStart:
 431                         message = "The process failed to start. Either the invoked program is missing, "
 432                                       "or you may have insufficient permissions to invoke the program.";
 433                         break;
 434                 case QProcess::Crashed:
 435                         message = "The process crashed some time after starting successfully.";
 436                         break;
 437                 case QProcess::Timedout:
 438                         message = "The process timed out. It might be restarted automatically.";
 439                         break;
 440                 case QProcess::WriteError:
 441                         message = "An error occurred when attempting to write to the process-> For example, "
 442                                       "the process may not be running, or it may have closed its input channel.";
 443                         break;
 444                 case QProcess::ReadError:
 445                         message = "An error occurred when attempting to read from the process-> For example, "
 446                                       "the process may not be running.";
 447                         break;
 448                 case QProcess::UnknownError:
 449                 default:
 450                         message = "An unknown error occured.";
 451                         break;
 452         }
 453         return message;
 454 }
 455
 456
 457 QString SystemcallPrivate::exitStatusMessage() const
 458 {
 459         if (!process_)
 460                 return "No QProcess available";
 461
 462         QString message;
 463         switch (process_->exitStatus()) {
 464                 case QProcess::NormalExit:
 465                         message = "The process exited normally.";
 466                         break;
 467                 case QProcess::CrashExit:
 468                         message = "The process crashed.";
 469                         break;
 470                 default:
 471                         message = "Unknown exit state.";
 472                         break;
 473         }
 474         return message;
 475 }
 476
 477
 478 int SystemcallPrivate::exitCode()
 479 {
 480         if (!process_)
 481                 return -1;
 482
 483         return process_->exitCode();
 484 }
 485
 486
 487 QProcess* SystemcallPrivate::releaseProcess()
 488 {
 489         QProcess* released = process_;
 490         process_ = 0;
 491         return released;
 492 }
 493
 494
 495 void SystemcallPrivate::killProcess()
 496 {
 497         killProcess(process_);
 498 }
 499
 500
 501 void SystemcallPrivate::killProcess(QProcess * p)
 502 {
 503         if (p) {
 504                 p->disconnect();
 505                 p->closeReadChannel(QProcess::StandardOutput);
 506                 p->closeReadChannel(QProcess::StandardError);
 507                 p->close();
 508                 delete p;
 509         }
 510 }
 511
 512
 513
 514 #include "moc_SystemcallPrivate.cpp"
 515 #endif
 516
 517 } // namespace support
 518 } // namespace lyx