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 command =
 104                 to_filesystem8bit(from_utf8(latexEnvCmdPrefix(path))) + what;
 105
 106         if (how == DontWait) {
 107                 switch (os::shell()) {
 108                 case os::UNIX:
 109                         command += " &";
 110                         break;
 111                 case os::CMD_EXE:
 112                         command = "start /min " + command;
 113                         break;
 114                 }
 115         } else if (os::shell() == os::CMD_EXE)
 116                 command = subst(command, "cmd /d /c ", "");
 117
 118         return ::system(command.c_str());
 119 }
 120
 121 #else
 122
 123 namespace {
 124
 125 /*
 126  * This is a parser that (mostly) mimics the behavior of a posix shell but
 127  * its output is tailored for being processed by QProcess.
 128  *
 129  * The escape character is the backslash.
 130  * A backslash that is not quoted preserves the literal value of the following
 131  * character, with the exception of a double-quote '"'. If a double-quote
 132  * follows a backslash, it will be replaced by three consecutive double-quotes
 133  * (this is how the QProcess parser recognizes a '"' as a simple character
 134  * instead of a quoting character). Thus, for example:
 135  *     \\  ->  \
 136  *     \a  ->  a
 137  *     \"  ->  """
 138  *
 139  * Single-quotes.
 140  * Characters enclosed in single-quotes ('') have their literal value preserved.
 141  * A single-quote cannot occur within single-quotes. Indeed, a backslash cannot
 142  * be used to escape a single-quote in a single-quoted string. In other words,
 143  * anything enclosed in single-quotes is passed as is, but the single-quotes
 144  * themselves are eliminated. Thus, for example:
 145  *    '\'    ->  \
 146  *    '\\'   ->  \\
 147  *    '\a'   ->  \a
 148  *    'a\"b' ->  a\"b
 149  *
 150  * Double-quotes.
 151  * Characters enclosed in double-quotes ("") have their literal value preserved,
 152  * with the exception of the backslash. The backslash retains its special
 153  * meaning as an escape character only when followed by a double-quote.
 154  * Contrarily to the behavior of a posix shell, the double-quotes themselves
 155  * are *not* eliminated. Thus, for example:
 156  *    "\\"   ->  "\\"
 157  *    "\a"   ->  "\a"
 158  *    "a\"b" ->  "a"""b"
 159  */
 160 string const parsecmd(string const & inputcmd, string & outfile)
 161 {
 162         bool in_single_quote = false;
 163         bool in_double_quote = false;
 164         bool escaped = false;
 165         string cmd;
 166
 167         for (size_t i = 0; i < inputcmd.length(); ++i) {
 168                 char c = inputcmd[i];
 169                 if (c == '\'') {
 170                         if (in_double_quote || escaped) {
 171                                 if (in_double_quote && escaped)
 172                                         cmd += '\\';
 173                                 cmd += c;
 174                         } else
 175                                 in_single_quote = !in_single_quote;
 176                         escaped = false;
 177                         continue;
 178                 }
 179                 if (in_single_quote) {
 180                         cmd += c;
 181                         continue;
 182                 }
 183                 if (c == '"') {
 184                         if (escaped) {
 185                                 cmd += "\"\"\"";
 186                                 escaped = false;
 187                         } else {
 188                                 cmd += c;
 189                                 in_double_quote = !in_double_quote;
 190                         }
 191                 } else if (c == '\\' && !escaped) {
 192                         escaped = !escaped;
 193                 } else if (c == '>' && !(in_double_quote || escaped)) {
 194                         outfile = trim(inputcmd.substr(i + 1), " \"");
 195                         return trim(cmd);
 196                 } else {
 197                         if (escaped && in_double_quote)
 198                                 cmd += '\\';
 199                         cmd += c;
 200                         escaped = false;
 201                 }
 202         }
 203         outfile.erase();
 204         return cmd;
 205 }
 206
 207 } // namespace anon
 208
 209
 210
 211 int Systemcall::startscript(Starttype how, string const & what,
 212                             string const & path, bool process_events)
 213 {
 214         string outfile;
 215         QString cmd = toqstr(parsecmd(what, outfile));
 216
 217         SystemcallPrivate d(outfile);
 218
 219
 220         d.startProcess(cmd, path);
 221         if (!d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 222                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 223                 LYXERR0("error " << d.errorMessage());
 224                 return 10;
 225         }
 226
 227         if (how == DontWait) {
 228                 QProcess* released = d.releaseProcess();
 229                 (void) released; // TODO who deletes it?
 230                 return 0;
 231         }
 232
 233         if (!d.waitWhile(SystemcallPrivate::Running, process_events,
 234                          os::timeout_min() * 60 * 1000)) {
 235                 LYXERR0("Systemcall: '" << cmd << "' did not finish!");
 236                 LYXERR0("error " << d.errorMessage());
 237                 LYXERR0("status " << d.exitStatusMessage());
 238                 return 20;
 239         }
 240
 241         int const exit_code = d.exitCode();
 242         if (exit_code) {
 243                 LYXERR0("Systemcall: '" << cmd << "' finished with exit code " << exit_code);
 244         }
 245
 246         return exit_code;
 247 }
 248
 249
 250 SystemcallPrivate::SystemcallPrivate(const std::string& of) :
 251                                 process_(new QProcess),
 252                                 out_index_(0),
 253                                 err_index_(0),
 254                                 out_file_(of),
 255                                 process_events_(false)
 256 {
 257         if (!out_file_.empty()) {
 258                 // Check whether we have to simply throw away the output.
 259                 if (out_file_ != os::nulldev())
 260                         process_->setStandardOutputFile(toqstr(out_file_));
 261         }
 262
 263         connect(process_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 264         connect(process_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 265         connect(process_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 266         connect(process_, SIGNAL(started()), this, SLOT(processStarted()));
 267         connect(process_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 268 }
 269
 270
 271 void SystemcallPrivate::startProcess(QString const & cmd, string const & path)
 272 {
 273         cmd_ = cmd;
 274         if (process_) {
 275                 state = SystemcallPrivate::Starting;
 276                 process_->start(toqstr(latexEnvCmdPrefix(path)) + cmd_);
 277         }
 278 }
 279
 280
 281 void SystemcallPrivate::processEvents()
 282 {
 283         if(process_events_) {
 284                 QCoreApplication::processEvents(/*QEventLoop::ExcludeUserInputEvents*/);
 285         }
 286 }
 287
 288
 289 void SystemcallPrivate::waitAndProcessEvents()
 290 {
 291         Sleep::millisec(100);
 292         processEvents();
 293 }
 294
 295
 296 bool SystemcallPrivate::waitWhile(State waitwhile, bool process_events, int timeout)
 297 {
 298         if (!process_)
 299                 return false;
 300
 301         process_events_ = process_events;
 302
 303         // Block GUI while waiting,
 304         // relay on QProcess' wait functions
 305         if (!process_events_) {
 306                 if (waitwhile == Starting)
 307                         return process_->waitForStarted(timeout);
 308                 if (waitwhile == Running)
 309                         return process_->waitForFinished(timeout);
 310                 return false;
 311         }
 312
 313         // process events while waiting, no timeout
 314         if (timeout == -1) {
 315                 while (state == waitwhile && state != Error) {
 316                         waitAndProcessEvents();
 317                 }
 318                 return state != Error;
 319         }
 320
 321         // process events while waiting whith timeout
 322         QTime timer;
 323         timer.start();
 324         while (state == waitwhile && state != Error && timer.elapsed() < timeout) {
 325                 waitAndProcessEvents();
 326         }
 327         return (state != Error) && (timer.elapsed() < timeout);
 328 }
 329
 330
 331 SystemcallPrivate::~SystemcallPrivate()
 332 {
 333         if (out_index_) {
 334                 out_data_[out_index_] = '\0';
 335                 out_index_ = 0;
 336                 cout << out_data_;
 337         }
 338         cout.flush();
 339         if (err_index_) {
 340                 err_data_[err_index_] = '\0';
 341                 err_index_ = 0;
 342                 cerr << err_data_;
 343         }
 344         cerr.flush();
 345
 346         killProcess();
 347 }
 348
 349
 350 void SystemcallPrivate::stdOut()
 351 {
 352         if (process_) {
 353                 char c;
 354                 process_->setReadChannel(QProcess::StandardOutput);
 355                 while (process_->getChar(&c)) {
 356                         out_data_[out_index_++] = c;
 357                         if (c == '\n' || out_index_ + 1 == buffer_size_) {
 358                                 out_data_[out_index_] = '\0';
 359                                 out_index_ = 0;
 360                                 ProgressInterface::instance()->appendMessage(QString::fromLocal8Bit(out_data_));
 361                                 cout << out_data_;
 362                         }
 363                 }
 364         }
 365 }
 366
 367
 368 void SystemcallPrivate::stdErr()
 369 {
 370         if (process_) {
 371                 char c;
 372                 process_->setReadChannel(QProcess::StandardError);
 373                 while (process_->getChar(&c)) {
 374                         err_data_[err_index_++] = c;
 375                         if (c == '\n' || err_index_ + 1 == buffer_size_) {
 376                                 err_data_[err_index_] = '\0';
 377                                 err_index_ = 0;
 378                                 ProgressInterface::instance()->appendError(QString::fromLocal8Bit(err_data_));
 379                                 cerr << err_data_;
 380                         }
 381                 }
 382         }
 383 }
 384
 385
 386 void SystemcallPrivate::processStarted()
 387 {
 388         if (state != Running) {
 389                 state = Running;
 390                 ProgressInterface::instance()->processStarted(cmd_);
 391         }
 392 }
 393
 394
 395 void SystemcallPrivate::processFinished(int, QProcess::ExitStatus)
 396 {
 397         if (state != Finished) {
 398                 state = Finished;
 399                 ProgressInterface::instance()->processFinished(cmd_);
 400         }
 401 }
 402
 403
 404 void SystemcallPrivate::processError(QProcess::ProcessError)
 405 {
 406         state = Error;
 407         ProgressInterface::instance()->appendError(errorMessage());
 408 }
 409
 410
 411 QString SystemcallPrivate::errorMessage() const
 412 {
 413         if (!process_)
 414                 return "No QProcess available";
 415
 416         QString message;
 417         switch (process_->error()) {
 418                 case QProcess::FailedToStart:
 419                         message = "The process failed to start. Either the invoked program is missing, "
 420                                       "or you may have insufficient permissions to invoke the program.";
 421                         break;
 422                 case QProcess::Crashed:
 423                         message = "The process crashed some time after starting successfully.";
 424                         break;
 425                 case QProcess::Timedout:
 426                         message = "The process timed out. It might be restarted automatically.";
 427                         break;
 428                 case QProcess::WriteError:
 429                         message = "An error occurred when attempting to write to the process-> For example, "
 430                                       "the process may not be running, or it may have closed its input channel.";
 431                         break;
 432                 case QProcess::ReadError:
 433                         message = "An error occurred when attempting to read from the process-> For example, "
 434                                       "the process may not be running.";
 435                         break;
 436                 case QProcess::UnknownError:
 437                 default:
 438                         message = "An unknown error occured.";
 439                         break;
 440         }
 441         return message;
 442 }
 443
 444
 445 QString SystemcallPrivate::exitStatusMessage() const
 446 {
 447         if (!process_)
 448                 return "No QProcess available";
 449
 450         QString message;
 451         switch (process_->exitStatus()) {
 452                 case QProcess::NormalExit:
 453                         message = "The process exited normally.";
 454                         break;
 455                 case QProcess::CrashExit:
 456                         message = "The process crashed.";
 457                         break;
 458                 default:
 459                         message = "Unknown exit state.";
 460                         break;
 461         }
 462         return message;
 463 }
 464
 465
 466 int SystemcallPrivate::exitCode()
 467 {
 468         if (!process_)
 469                 return -1;
 470
 471         return process_->exitCode();
 472 }
 473
 474
 475 QProcess* SystemcallPrivate::releaseProcess()
 476 {
 477         QProcess* released = process_;
 478         process_ = 0;
 479         return released;
 480 }
 481
 482
 483 void SystemcallPrivate::killProcess()
 484 {
 485         killProcess(process_);
 486 }
 487
 488
 489 void SystemcallPrivate::killProcess(QProcess * p)
 490 {
 491         if (p) {
 492                 p->disconnect();
 493                 p->closeReadChannel(QProcess::StandardOutput);
 494                 p->closeReadChannel(QProcess::StandardError);
 495                 p->close();
 496                 delete p;
 497         }
 498 }
 499
 500
 501
 502 #include "moc_SystemcallPrivate.cpp"
 503 #endif
 504
 505 } // namespace support
 506 } // namespace lyx