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/lstrings.h"
  18 #include "support/qstring_helpers.h"
  19 #include "support/Systemcall.h"
  20 #include "support/SystemcallPrivate.h"
  21 #include "support/os.h"
  22 #include "support/ProgressInterface.h"
  23
  24
  25 #include <cstdlib>
  26 #include <iostream>
  27
  28 #include <QProcess>
  29 #include <QTime>
  30 #include <QThread>
  31 #include <QCoreApplication>
  32 #include <QDebug>
  33
  34 #define USE_QPROCESS
  35
  36
  37 struct Sleep : QThread
  38 {
  39         static void millisec(unsigned long ms)
  40         {
  41                 QThread::usleep(ms * 1000);
  42         }
  43 };
  44
  45
  46
  47
  48 using namespace std;
  49
  50 namespace lyx {
  51 namespace support {
  52
  53
  54 class ProgressDummy : public ProgressInterface
  55 {
  56 public:
  57         ProgressDummy() {}
  58
  59         void processStarted(QString const &) {}
  60         void processFinished(QString const &) {}
  61         void appendMessage(QString const &) {}
  62         void appendError(QString const &) {}
  63         void clearMessages() {}
  64         void lyxerrFlush() {}
  65
  66         void lyxerrConnect() {}
  67         void lyxerrDisconnect() {}
  68
  69         void warning(QString const &, QString const &) {}
  70         void toggleWarning(QString const &, QString const &, QString const &) {}
  71         void error(QString const &, QString const &) {}
  72         void information(QString const &, QString const &) {}
  73 };
  74
  75
  76 static ProgressInterface* progress_instance = 0;
  77
  78 void ProgressInterface::setInstance(ProgressInterface* p)
  79 {
  80         progress_instance = p;
  81 }
  82
  83
  84 ProgressInterface* ProgressInterface::instance()
  85 {
  86         if (!progress_instance) {
  87                 static ProgressDummy dummy;
  88                 return &dummy;
  89         }
  90         return progress_instance;
  91 }
  92
  93
  94
  95
  96 // Reuse of instance
  97 #ifndef USE_QPROCESS
  98 int Systemcall::startscript(Starttype how, string const & what,
  99                                                         bool /*process_events*/)
 100 {
 101         string command = what;
 102
 103         if (how == DontWait) {
 104                 switch (os::shell()) {
 105                 case os::UNIX:
 106                         command += " &";
 107                         break;
 108                 case os::CMD_EXE:
 109                         command = "start /min " + command;
 110                         break;
 111                 }
 112         }
 113
 114         return ::system(command.c_str());
 115 }
 116
 117 #else
 118
 119 namespace {
 120
 121 /*
 122  * This is a parser that (mostly) mimics the behavior of a posix shell but
 123  * its output is tailored for being processed by QProcess.
 124  *
 125  * The escape character is the backslash.
 126  * A backslash that is not quoted preserves the literal value of the following
 127  * character, with the exception of a double-quote '"'. If a double-quote
 128  * follows a backslash, it will be replaced by three consecutive double-quotes
 129  * (this is how the QProcess parser recognizes a '"' as a simple character
 130  * instead of a quoting character). Thus, for example:
 131  *     \\  ->  \
 132  *     \a  ->  a
 133  *     \"  ->  """
 134  *
 135  * Single-quotes.
 136  * Characters enclosed in single-quotes ('') have their literal value preserved.
 137  * A single-quote cannot occur within single-quotes. Indeed, a backslash cannot
 138  * be used to escape a single-quote in a single-quoted string. In other words,
 139  * anything enclosed in single-quotes is passed as is, but the single-quotes
 140  * themselves are eliminated. Thus, for example:
 141  *    '\'    ->  \
 142  *    '\\'   ->  \\
 143  *    '\a'   ->  \a
 144  *    'a\"b' ->  a\"b
 145  *
 146  * Double-quotes.
 147  * Characters enclosed in double-quotes ("") have their literal value preserved,
 148  * with the exception of the backslash. The backslash retains its special
 149  * meaning as an escape character only when followed by a double-quote.
 150  * Contrarily to the behavior of a posix shell, the double-quotes themselves
 151  * are *not* eliminated. Thus, for example:
 152  *    "\\"   ->  "\\"
 153  *    "\a"   ->  "\a"
 154  *    "a\"b" ->  "a"""b"
 155  */
 156 string const parsecmd(string const & inputcmd, string & outfile)
 157 {
 158         bool in_single_quote = false;
 159         bool in_double_quote = false;
 160         bool escaped = false;
 161         string cmd;
 162
 163         for (size_t i = 0; i < inputcmd.length(); ++i) {
 164                 char c = inputcmd[i];
 165                 if (c == '\'') {
 166                         if (in_double_quote || escaped) {
 167                                 if (in_double_quote && escaped)
 168                                         cmd += '\\';
 169                                 cmd += c;
 170                         } else
 171                                 in_single_quote = !in_single_quote;
 172                         escaped = false;
 173                         continue;
 174                 }
 175                 if (in_single_quote) {
 176                         cmd += c;
 177                         continue;
 178                 }
 179                 if (c == '"') {
 180                         if (escaped) {
 181                                 cmd += "\"\"\"";
 182                                 escaped = false;
 183                         } else {
 184                                 cmd += c;
 185                                 in_double_quote = !in_double_quote;
 186                         }
 187                 } else if (c == '\\' && !escaped) {
 188                         escaped = !escaped;
 189                 } else if (c == '>' && !(in_double_quote || escaped)) {
 190                         outfile = trim(inputcmd.substr(i + 1), " \"");
 191                         return trim(cmd);
 192                 } else {
 193                         if (escaped && in_double_quote)
 194                                 cmd += '\\';
 195                         cmd += c;
 196                         escaped = false;
 197                 }
 198         }
 199         outfile.erase();
 200         return cmd;
 201 }
 202
 203 } // namespace anon
 204
 205
 206
 207 int Systemcall::startscript(Starttype how, string const & what, bool process_events)
 208 {
 209         string outfile;
 210         QString cmd = toqstr(parsecmd(what, outfile));
 211
 212         SystemcallPrivate d(outfile);
 213
 214
 215         d.startProcess(cmd);
 216         if (!d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 217                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 218                 LYXERR0("error " << d.errorMessage());
 219                 return 10;
 220         }
 221
 222         if (how == DontWait) {
 223                 QProcess* released = d.releaseProcess();
 224                 (void) released; // TODO who deletes it?
 225                 return 0;
 226         }
 227
 228         if (!d.waitWhile(SystemcallPrivate::Running, process_events, 180000)) {
 229                 LYXERR0("Systemcall: '" << cmd << "' did not finished!");
 230                 LYXERR0("error " << d.errorMessage());
 231                 LYXERR0("status " << d.exitStatusMessage());
 232                 return 20;
 233         }
 234
 235         int const exit_code = d.exitCode();
 236         if (exit_code) {
 237                 LYXERR0("Systemcall: '" << cmd << "' finished with exit code " << exit_code);
 238         }
 239
 240         return exit_code;
 241 }
 242
 243
 244 SystemcallPrivate::SystemcallPrivate(const std::string& of) :
 245                                 process_(new QProcess),
 246                                 out_index_(0),
 247                                 err_index_(0),
 248                                 out_file_(of),
 249                                 terminal_out_exists_(os::is_terminal(os::STDOUT)),
 250                                 terminal_err_exists_(os::is_terminal(os::STDERR)),
 251                                 process_events_(false)
 252 {
 253         if (!out_file_.empty()) {
 254                 // Check whether we have to simply throw away the output.
 255                 if (out_file_ != os::nulldev())
 256                         process_->setStandardOutputFile(toqstr(out_file_));
 257         }
 258
 259         connect(process_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 260         connect(process_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 261         connect(process_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 262         connect(process_, SIGNAL(started()), this, SLOT(processStarted()));
 263         connect(process_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 264 }
 265
 266
 267
 268 void SystemcallPrivate::startProcess(const QString& cmd)
 269 {
 270         cmd_ = cmd;
 271         if (process_) {
 272                 state = SystemcallPrivate::Starting;
 273                 process_->start(cmd_);
 274         }
 275 }
 276
 277
 278 void SystemcallPrivate::processEvents()
 279 {
 280         if(process_events_) {
 281                 QCoreApplication::processEvents(/*QEventLoop::ExcludeUserInputEvents*/);
 282         }
 283 }
 284
 285
 286 void SystemcallPrivate::waitAndProcessEvents()
 287 {
 288         Sleep::millisec(100);
 289         processEvents();
 290 }
 291
 292
 293 bool SystemcallPrivate::waitWhile(State waitwhile, bool process_events, int timeout)
 294 {
 295         if (!process_)
 296                 return false;
 297
 298         process_events = process_events;
 299
 300         // Block GUI while waiting,
 301         // relay on QProcess' wait functions
 302         if (!process_events) {
 303                 if (waitwhile == Starting)
 304                         return process_->waitForStarted(timeout);
 305                 if (waitwhile == Running)
 306                         return process_->waitForFinished(timeout);
 307                 return false;
 308         }
 309
 310         // process events while waiting, no timeout
 311         if (timeout == -1) {
 312                 while (state == waitwhile && state != Error) {
 313                         waitAndProcessEvents();
 314                 }
 315                 return state != Error;
 316         }
 317
 318         // process events while waiting whith timeout
 319         QTime timer;
 320         timer.start();
 321         while (state == waitwhile && state != Error && timer.elapsed() < timeout) {
 322                 waitAndProcessEvents();
 323         }
 324         return (state != Error) && (timer.elapsed() < timeout);
 325 }
 326
 327
 328 SystemcallPrivate::~SystemcallPrivate()
 329 {
 330         flush();
 331
 332         if (out_index_) {
 333                 out_data_[out_index_] = '\0';
 334                 out_index_ = 0;
 335                 if (terminal_out_exists_)
 336                         cout << out_data_;
 337         }
 338         cout.flush();
 339         if (err_index_) {
 340                 err_data_[err_index_] = '\0';
 341                 err_index_ = 0;
 342                 if (terminal_err_exists_)
 343                         cerr << err_data_;
 344         }
 345         cerr.flush();
 346
 347         killProcess();
 348 }
 349
 350
 351 void SystemcallPrivate::flush()
 352 {
 353         if (process_) {
 354                 // If the output has been redirected, we write it all at once.
 355                 // Even if we are not running in a terminal, the output could go
 356                 // to some log file, for example ~/.xsession-errors on *nix.
 357
 358                 QString data = QString::fromLocal8Bit(process_->readAllStandardOutput().data());
 359                 ProgressInterface::instance()->appendMessage(data);
 360                 if (!terminal_out_exists_ && out_file_.empty())
 361                         cout << fromqstr(data);
 362
 363                 data = QString::fromLocal8Bit(process_->readAllStandardError().data());
 364                 ProgressInterface::instance()->appendError(data);
 365                 if (!terminal_err_exists_)
 366                         cerr << fromqstr(data);
 367         }
 368 }
 369
 370
 371 void SystemcallPrivate::stdOut()
 372 {
 373         if (process_) {
 374                 char c;
 375                 process_->setReadChannel(QProcess::StandardOutput);
 376                 while (process_->getChar(&c)) {
 377                         out_data_[out_index_++] = c;
 378                         if (c == '\n' || out_index_ + 1 == max_buffer_size_) {
 379                                 out_data_[out_index_] = '\0';
 380                                 out_index_ = 0;
 381                                 ProgressInterface::instance()->appendMessage(QString::fromLocal8Bit(out_data_));
 382                                 if (terminal_out_exists_)
 383                                         cout << out_data_;
 384                         }
 385                 }
 386         }
 387 }
 388
 389
 390 void SystemcallPrivate::stdErr()
 391 {
 392         if (process_) {
 393                 char c;
 394                 process_->setReadChannel(QProcess::StandardError);
 395                 while (process_->getChar(&c)) {
 396                         err_data_[err_index_++] = c;
 397                         if (c == '\n' || err_index_ + 1 == max_buffer_size_) {
 398                                 err_data_[err_index_] = '\0';
 399                                 err_index_ = 0;
 400                                 ProgressInterface::instance()->appendError(QString::fromLocal8Bit(err_data_));
 401                                 if (terminal_err_exists_)
 402                                         cerr << err_data_;
 403                         }
 404                 }
 405         }
 406 }
 407
 408
 409 void SystemcallPrivate::processStarted()
 410 {
 411         if (state != Running) {
 412                 state = Running;
 413                 ProgressInterface::instance()->processStarted(cmd_);
 414         }
 415 }
 416
 417
 418 void SystemcallPrivate::processFinished(int, QProcess::ExitStatus)
 419 {
 420         if (state != Finished) {
 421                 state = Finished;
 422                 ProgressInterface::instance()->processFinished(cmd_);
 423         }
 424 }
 425
 426
 427 void SystemcallPrivate::processError(QProcess::ProcessError)
 428 {
 429         state = Error;
 430         ProgressInterface::instance()->appendError(errorMessage());
 431 }
 432
 433
 434 QString SystemcallPrivate::errorMessage() const
 435 {
 436         if (!process_)
 437                 return "No QProcess available";
 438
 439         QString message;
 440         switch (process_->error()) {
 441                 case QProcess::FailedToStart:
 442                         message = "The process failed to start. Either the invoked program is missing, "
 443                                       "or you may have insufficient permissions to invoke the program.";
 444                         break;
 445                 case QProcess::Crashed:
 446                         message = "The process crashed some time after starting successfully.";
 447                         break;
 448                 case QProcess::Timedout:
 449                         message = "The process timed out. It might be restarted automatically.";
 450                         break;
 451                 case QProcess::WriteError:
 452                         message = "An error occurred when attempting to write to the process-> For example, "
 453                                       "the process may not be running, or it may have closed its input channel.";
 454                         break;
 455                 case QProcess::ReadError:
 456                         message = "An error occurred when attempting to read from the process-> For example, "
 457                                       "the process may not be running.";
 458                         break;
 459                 case QProcess::UnknownError:
 460                 default:
 461                         message = "An unknown error occured.";
 462                         break;
 463         }
 464         return message;
 465 }
 466
 467
 468 QString SystemcallPrivate::exitStatusMessage() const
 469 {
 470         if (!process_)
 471                 return "No QProcess available";
 472
 473         QString message;
 474         switch (process_->exitStatus()) {
 475                 case QProcess::NormalExit:
 476                         message = "The process exited normally.";
 477                         break;
 478                 case QProcess::CrashExit:
 479                         message = "The process crashed.";
 480                         break;
 481                 default:
 482                         message = "Unknown exit state.";
 483                         break;
 484         }
 485         return message;
 486 }
 487
 488
 489 int SystemcallPrivate::exitCode()
 490 {
 491         if (!process_)
 492                 return -1;
 493
 494         return process_->exitCode();
 495 }
 496
 497
 498 QProcess* SystemcallPrivate::releaseProcess()
 499 {
 500         QProcess* released = process_;
 501         process_ = 0;
 502         return released;
 503 }
 504
 505
 506 void SystemcallPrivate::killProcess()
 507 {
 508         killProcess(process_);
 509 }
 510
 511
 512 void SystemcallPrivate::killProcess(QProcess * p)
 513 {
 514         if (p) {
 515                 p->disconnect();
 516                 p->closeReadChannel(QProcess::StandardOutput);
 517                 p->closeReadChannel(QProcess::StandardError);
 518                 p->close();
 519                 delete p;
 520         }
 521 }
 522
 523
 524
 525 #include "moc_SystemcallPrivate.cpp"
 526 #endif
 527
 528 } // namespace support
 529 } // namespace lyx