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                                 use_stdout_(false),
 250                                 use_stderr_(false),
 251                                 process_events_(false)
 252 {
 253         if (!out_file_.empty()) {
 254                 // Don't output to terminal if stdout is redirected
 255                 use_stdout_ = false;
 256                 // Check whether we have to simply throw away the output.
 257                 if (out_file_ != os::nulldev())
 258                         process_->setStandardOutputFile(toqstr(out_file_));
 259         } else {
 260                 // Output to terminal if stdout exists and is not redirected
 261                 use_stdout_ = os::is_terminal(os::STDOUT);
 262         }
 263
 264         // When there is a stderr use it
 265         use_stderr_ = os::is_terminal(os::STDERR);
 266
 267         connect(process_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 268         connect(process_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 269         connect(process_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 270         connect(process_, SIGNAL(started()), this, SLOT(processStarted()));
 271         connect(process_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 272 }
 273
 274
 275
 276 void SystemcallPrivate::startProcess(const QString& cmd)
 277 {
 278         cmd_ = cmd;
 279         if (process_) {
 280                 state = SystemcallPrivate::Starting;
 281                 process_->start(cmd_);
 282         }
 283 }
 284
 285
 286 void SystemcallPrivate::processEvents()
 287 {
 288         if(process_events_) {
 289                 QCoreApplication::processEvents(/*QEventLoop::ExcludeUserInputEvents*/);
 290         }
 291 }
 292
 293
 294 void SystemcallPrivate::waitAndProcessEvents()
 295 {
 296         Sleep::millisec(100);
 297         processEvents();
 298 }
 299
 300
 301 bool SystemcallPrivate::waitWhile(State waitwhile, bool process_events, int timeout)
 302 {
 303         if (!process_)
 304                 return false;
 305
 306         process_events_ = process_events;
 307
 308         // Block GUI while waiting,
 309         // relay on QProcess' wait functions
 310         if (!process_events_) {
 311                 if (waitwhile == Starting)
 312                         return process_->waitForStarted(timeout);
 313                 if (waitwhile == Running)
 314                         return process_->waitForFinished(timeout);
 315                 return false;
 316         }
 317
 318         // process events while waiting, no timeout
 319         if (timeout == -1) {
 320                 while (state == waitwhile && state != Error) {
 321                         waitAndProcessEvents();
 322                 }
 323                 return state != Error;
 324         }
 325
 326         // process events while waiting whith timeout
 327         QTime timer;
 328         timer.start();
 329         while (state == waitwhile && state != Error && timer.elapsed() < timeout) {
 330                 waitAndProcessEvents();
 331         }
 332         return (state != Error) && (timer.elapsed() < timeout);
 333 }
 334
 335
 336 SystemcallPrivate::~SystemcallPrivate()
 337 {
 338         flush();
 339
 340         if (out_index_) {
 341                 out_data_[out_index_] = '\0';
 342                 out_index_ = 0;
 343                 if (use_stdout_)
 344                         cout << out_data_;
 345         }
 346         cout.flush();
 347         if (err_index_) {
 348                 err_data_[err_index_] = '\0';
 349                 err_index_ = 0;
 350                 if (use_stderr_)
 351                         cerr << err_data_;
 352         }
 353         cerr.flush();
 354
 355         killProcess();
 356 }
 357
 358
 359 void SystemcallPrivate::flush()
 360 {
 361         if (process_) {
 362                 // If the output has been redirected, we write it all at once.
 363                 // Even if we are not running in a terminal, the output could go
 364                 // to some log file, for example ~/.xsession-errors on *nix.
 365
 366                 QString data = QString::fromLocal8Bit(process_->readAllStandardOutput().data());
 367                 ProgressInterface::instance()->appendMessage(data);
 368                 if (!use_stdout_ && out_file_.empty())
 369                         cout << fromqstr(data);
 370
 371                 data = QString::fromLocal8Bit(process_->readAllStandardError().data());
 372                 ProgressInterface::instance()->appendError(data);
 373                 if (!use_stderr_)
 374                         cerr << fromqstr(data);
 375         }
 376 }
 377
 378
 379 void SystemcallPrivate::stdOut()
 380 {
 381         if (process_) {
 382                 char c;
 383                 process_->setReadChannel(QProcess::StandardOutput);
 384                 while (process_->getChar(&c)) {
 385                         out_data_[out_index_++] = c;
 386                         if (c == '\n' || out_index_ + 1 == max_buffer_size_) {
 387                                 out_data_[out_index_] = '\0';
 388                                 out_index_ = 0;
 389                                 ProgressInterface::instance()->appendMessage(QString::fromLocal8Bit(out_data_));
 390                                 if (use_stdout_)
 391                                         cout << out_data_;
 392                         }
 393                 }
 394         }
 395 }
 396
 397
 398 void SystemcallPrivate::stdErr()
 399 {
 400         if (process_) {
 401                 char c;
 402                 process_->setReadChannel(QProcess::StandardError);
 403                 while (process_->getChar(&c)) {
 404                         err_data_[err_index_++] = c;
 405                         if (c == '\n' || err_index_ + 1 == max_buffer_size_) {
 406                                 err_data_[err_index_] = '\0';
 407                                 err_index_ = 0;
 408                                 ProgressInterface::instance()->appendError(QString::fromLocal8Bit(err_data_));
 409                                 if (use_stderr_)
 410                                         cerr << err_data_;
 411                         }
 412                 }
 413         }
 414 }
 415
 416
 417 void SystemcallPrivate::processStarted()
 418 {
 419         if (state != Running) {
 420                 state = Running;
 421                 ProgressInterface::instance()->processStarted(cmd_);
 422         }
 423 }
 424
 425
 426 void SystemcallPrivate::processFinished(int, QProcess::ExitStatus)
 427 {
 428         if (state != Finished) {
 429                 state = Finished;
 430                 ProgressInterface::instance()->processFinished(cmd_);
 431         }
 432 }
 433
 434
 435 void SystemcallPrivate::processError(QProcess::ProcessError)
 436 {
 437         state = Error;
 438         ProgressInterface::instance()->appendError(errorMessage());
 439 }
 440
 441
 442 QString SystemcallPrivate::errorMessage() const
 443 {
 444         if (!process_)
 445                 return "No QProcess available";
 446
 447         QString message;
 448         switch (process_->error()) {
 449                 case QProcess::FailedToStart:
 450                         message = "The process failed to start. Either the invoked program is missing, "
 451                                       "or you may have insufficient permissions to invoke the program.";
 452                         break;
 453                 case QProcess::Crashed:
 454                         message = "The process crashed some time after starting successfully.";
 455                         break;
 456                 case QProcess::Timedout:
 457                         message = "The process timed out. It might be restarted automatically.";
 458                         break;
 459                 case QProcess::WriteError:
 460                         message = "An error occurred when attempting to write to the process-> For example, "
 461                                       "the process may not be running, or it may have closed its input channel.";
 462                         break;
 463                 case QProcess::ReadError:
 464                         message = "An error occurred when attempting to read from the process-> For example, "
 465                                       "the process may not be running.";
 466                         break;
 467                 case QProcess::UnknownError:
 468                 default:
 469                         message = "An unknown error occured.";
 470                         break;
 471         }
 472         return message;
 473 }
 474
 475
 476 QString SystemcallPrivate::exitStatusMessage() const
 477 {
 478         if (!process_)
 479                 return "No QProcess available";
 480
 481         QString message;
 482         switch (process_->exitStatus()) {
 483                 case QProcess::NormalExit:
 484                         message = "The process exited normally.";
 485                         break;
 486                 case QProcess::CrashExit:
 487                         message = "The process crashed.";
 488                         break;
 489                 default:
 490                         message = "Unknown exit state.";
 491                         break;
 492         }
 493         return message;
 494 }
 495
 496
 497 int SystemcallPrivate::exitCode()
 498 {
 499         if (!process_)
 500                 return -1;
 501
 502         return process_->exitCode();
 503 }
 504
 505
 506 QProcess* SystemcallPrivate::releaseProcess()
 507 {
 508         QProcess* released = process_;
 509         process_ = 0;
 510         return released;
 511 }
 512
 513
 514 void SystemcallPrivate::killProcess()
 515 {
 516         killProcess(process_);
 517 }
 518
 519
 520 void SystemcallPrivate::killProcess(QProcess * p)
 521 {
 522         if (p) {
 523                 p->disconnect();
 524                 p->closeReadChannel(QProcess::StandardOutput);
 525                 p->closeReadChannel(QProcess::StandardError);
 526                 p->close();
 527                 delete p;
 528         }
 529 }
 530
 531
 532
 533 #include "moc_SystemcallPrivate.cpp"
 534 #endif
 535
 536 } // namespace support
 537 } // namespace lyx