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 //#define DEBUG_SYSTEMCALL // this macro shows the Qt 4.5 & 4.6 bug on Linux: multiple started() signals
  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
  65         void warning(QString const &, QString const &) {}
  66         void toggleWarning(QString const &, QString const &, QString const &) {}
  67         void error(QString const &, QString const &) {}
  68         void information(QString const &, QString const &) {}
  69 };
  70
  71
  72 static ProgressInterface* progress_instance = 0;
  73
  74 void ProgressInterface::setInstance(ProgressInterface* p)
  75 {
  76         progress_instance = p;
  77 }
  78
  79
  80 ProgressInterface* ProgressInterface::instance()
  81 {
  82         if (!progress_instance) {
  83                 static ProgressDummy dummy;
  84                 return &dummy;
  85         }
  86         return progress_instance;
  87 }
  88
  89
  90
  91
  92 // Reuse of instance
  93 #ifndef USE_QPROCESS
  94 int Systemcall::startscript(Starttype how, string const & what,
  95                                                         bool /*process_events*/)
  96 {
  97         string command = what;
  98
  99         if (how == DontWait) {
 100                 switch (os::shell()) {
 101                 case os::UNIX:
 102                         command += " &";
 103                         break;
 104                 case os::CMD_EXE:
 105                         command = "start /min " + command;
 106                         break;
 107                 }
 108         }
 109
 110         return ::system(command.c_str());
 111 }
 112
 113 #else
 114
 115 namespace {
 116
 117 /*
 118  * This is a parser that (mostly) mimics the behavior of a posix shell but
 119  * its output is tailored for being processed by QProcess.
 120  *
 121  * The escape character is the backslash.
 122  * A backslash that is not quoted preserves the literal value of the following
 123  * character, with the exception of a double-quote '"'. If a double-quote
 124  * follows a backslash, it will be replaced by three consecutive double-quotes
 125  * (this is how the QProcess parser recognizes a '"' as a simple character
 126  * instead of a quoting character). Thus, for example:
 127  *     \\  ->  \
 128  *     \a  ->  a
 129  *     \"  ->  """
 130  *
 131  * Single-quotes.
 132  * Characters enclosed in single-quotes ('') have their literal value preserved.
 133  * A single-quote cannot occur within single-quotes. Indeed, a backslash cannot
 134  * be used to escape a single-quote in a single-quoted string. In other words,
 135  * anything enclosed in single-quotes is passed as is, but the single-quotes
 136  * themselves are eliminated. Thus, for example:
 137  *    '\'    ->  \
 138  *    '\\'   ->  \\
 139  *    '\a'   ->  \a
 140  *    'a\"b' ->  a\"b
 141  *
 142  * Double-quotes.
 143  * Characters enclosed in double-quotes ("") have their literal value preserved,
 144  * with the exception of the backslash. The backslash retains its special
 145  * meaning as an escape character only when followed by a double-quote.
 146  * Contrarily to the behavior of a posix shell, the double-quotes themselves
 147  * are *not* eliminated. Thus, for example:
 148  *    "\\"   ->  "\\"
 149  *    "\a"   ->  "\a"
 150  *    "a\"b" ->  "a"""b"
 151  */
 152 string const parsecmd(string const & inputcmd, string & outfile)
 153 {
 154         bool in_single_quote = false;
 155         bool in_double_quote = false;
 156         bool escaped = false;
 157         string cmd;
 158
 159         for (size_t i = 0; i < inputcmd.length(); ++i) {
 160                 char c = inputcmd[i];
 161                 if (c == '\'') {
 162                         if (in_double_quote || escaped) {
 163                                 if (in_double_quote && escaped)
 164                                         cmd += '\\';
 165                                 cmd += c;
 166                         } else
 167                                 in_single_quote = !in_single_quote;
 168                         escaped = false;
 169                         continue;
 170                 }
 171                 if (in_single_quote) {
 172                         cmd += c;
 173                         continue;
 174                 }
 175                 if (c == '"') {
 176                         if (escaped) {
 177                                 cmd += "\"\"\"";
 178                                 escaped = false;
 179                         } else {
 180                                 cmd += c;
 181                                 in_double_quote = !in_double_quote;
 182                         }
 183                 } else if (c == '\\' && !escaped) {
 184                         escaped = !escaped;
 185                 } else if (c == '>' && !(in_double_quote || escaped)) {
 186                         outfile = trim(inputcmd.substr(i + 1), " \"");
 187                         return trim(cmd);
 188                 } else {
 189                         if (escaped && in_double_quote)
 190                                 cmd += '\\';
 191                         cmd += c;
 192                         escaped = false;
 193                 }
 194         }
 195         outfile.erase();
 196         return cmd;
 197 }
 198
 199 } // namespace anon
 200
 201
 202
 203 int Systemcall::startscript(Starttype how, string const & what, bool process_events)
 204 {
 205         string outfile;
 206         QString cmd = toqstr(parsecmd(what, outfile));
 207
 208         SystemcallPrivate d(outfile);
 209
 210
 211         d.startProcess(cmd);
 212         if (!d.waitWhile(SystemcallPrivate::Starting, process_events, -1)) {
 213                 LYXERR0("Systemcall: '" << cmd << "' did not start!");
 214                 LYXERR0("error " << d.errorMessage());
 215                 return 10;
 216         }
 217
 218         if (how == DontWait) {
 219                 QProcess* released = d.releaseProcess();
 220                 (void) released; // TODO who deletes it?
 221                 return 0;
 222         }
 223
 224         if (!d.waitWhile(SystemcallPrivate::Running, process_events, 180000)) {
 225                 LYXERR0("Systemcall: '" << cmd << "' did not finished!");
 226                 LYXERR0("error " << d.errorMessage());
 227                 LYXERR0("status " << d.exitStatusMessage());
 228                 return 20;
 229         }
 230
 231         int const exit_code = d.exitCode();
 232         if (exit_code) {
 233                 LYXERR0("Systemcall: '" << cmd << "' finished with exit code " << exit_code);
 234         }
 235
 236         return exit_code;
 237 }
 238
 239
 240 SystemcallPrivate::SystemcallPrivate(const std::string& of) :
 241                                 proc_(new QProcess), outindex_(0), errindex_(0),
 242                                 outfile(of), showout_(false), showerr_(false), process_events(false)
 243 {
 244         if (!outfile.empty()) {
 245                 // Check whether we have to simply throw away the output.
 246                 if (outfile != os::nulldev())
 247                         proc_->setStandardOutputFile(toqstr(outfile));
 248         } else if (os::is_terminal(os::STDOUT))
 249                 setShowOut(true);
 250         if (os::is_terminal(os::STDERR))
 251                 setShowErr(true);
 252
 253         connect(proc_, SIGNAL(readyReadStandardOutput()), SLOT(stdOut()));
 254         connect(proc_, SIGNAL(readyReadStandardError()), SLOT(stdErr()));
 255         connect(proc_, SIGNAL(error(QProcess::ProcessError)), SLOT(processError(QProcess::ProcessError)));
 256         connect(proc_, SIGNAL(started()), this, SLOT(processStarted()));
 257         connect(proc_, SIGNAL(finished(int, QProcess::ExitStatus)), SLOT(processFinished(int, QProcess::ExitStatus)));
 258 }
 259
 260
 261
 262 void SystemcallPrivate::startProcess(const QString& cmd)
 263 {
 264         cmd_ = cmd;
 265         if (proc_) {
 266                 state = SystemcallPrivate::Starting;
 267                 proc_->start(cmd_);
 268         }
 269 }
 270
 271
 272 void SystemcallPrivate::processEvents()
 273 {
 274         if(process_events) {
 275                 QCoreApplication::processEvents(/*QEventLoop::ExcludeUserInputEvents*/);
 276         }
 277 }
 278
 279
 280 void SystemcallPrivate::waitAndProcessEvents()
 281 {
 282         Sleep::millisec(100);
 283         processEvents();
 284 }
 285
 286
 287 bool SystemcallPrivate::waitWhile(State waitwhile, bool proc_events, int timeout)
 288 {
 289         if (!proc_)
 290                 return false;
 291
 292         process_events = proc_events;
 293
 294         // Block GUI while waiting,
 295         // relay on QProcess' wait functions
 296         if (!process_events) {
 297                 if (waitwhile == Starting)
 298                         return proc_->waitForStarted(timeout);
 299                 if (waitwhile == Running)
 300                         return proc_->waitForFinished(timeout);
 301                 return false;
 302         }
 303
 304         // process events while waiting, no timeout
 305         if (timeout == -1) {
 306                 while (state == waitwhile && state != Error) {
 307                         waitAndProcessEvents();
 308                 }
 309                 return state != Error;
 310         }
 311
 312         // process events while waiting whith timeout
 313         QTime timer;
 314         timer.start();
 315         while (state == waitwhile && state != Error && timer.elapsed() < timeout) {
 316                 waitAndProcessEvents();
 317         }
 318         return (state != Error) && (timer.elapsed() < timeout);
 319 }
 320
 321
 322 SystemcallPrivate::~SystemcallPrivate()
 323 {
 324         flush();
 325
 326         if (outindex_) {
 327                 outdata_[outindex_] = '\0';
 328                 outindex_ = 0;
 329                 if (showout_)
 330                         cout << outdata_;
 331         }
 332         cout.flush();
 333         if (errindex_) {
 334                 errdata_[errindex_] = '\0';
 335                 errindex_ = 0;
 336                 if (showerr_)
 337                         cerr << errdata_;
 338         }
 339         cerr.flush();
 340
 341         killProcess();
 342 }
 343
 344
 345 void SystemcallPrivate::flush()
 346 {
 347         if (proc_) {
 348                 // If the output has been redirected, we write it all at once.
 349                 // Even if we are not running in a terminal, the output could go
 350                 // to some log file, for example ~/.xsession-errors on *nix.
 351
 352                 QString data = QString::fromLocal8Bit(proc_->readAllStandardOutput().data());
 353                 if (showout_)
 354                         ProgressInterface::instance()->appendMessage(data);
 355                 if (!os::is_terminal(os::STDOUT) && outfile.empty())
 356                         cout << fromqstr(data);
 357
 358                 data = QString::fromLocal8Bit(proc_->readAllStandardError().data());
 359                 if (showerr_)
 360                         ProgressInterface::instance()->appendError(data);
 361                 if (!os::is_terminal(os::STDERR))
 362                         cerr << fromqstr(data);
 363
 364         }
 365 }
 366
 367
 368 void SystemcallPrivate::stdOut()
 369 {
 370         if (proc_) {
 371                 char c;
 372                 proc_->setReadChannel(QProcess::StandardOutput);
 373                 while (proc_->getChar(&c)) {
 374                         outdata_[outindex_++] = c;
 375                         if (c == '\n' || outindex_ + 1 == bufsize_) {
 376                                 outdata_[outindex_] = '\0';
 377                                 outindex_ = 0;
 378                                 if (showout_) {
 379                                         cout << outdata_;
 380                                         ProgressInterface::instance()->appendMessage(QString::fromLocal8Bit(outdata_));
 381                                 }
 382                         }
 383                 }
 384         }
 385 }
 386
 387
 388 void SystemcallPrivate::stdErr()
 389 {
 390         if (proc_) {
 391                 char c;
 392                 proc_->setReadChannel(QProcess::StandardError);
 393                 while (proc_->getChar(&c)) {
 394                         errdata_[errindex_++] = c;
 395                         if (c == '\n' || errindex_ + 1 == bufsize_) {
 396                                 errdata_[errindex_] = '\0';
 397                                 errindex_ = 0;
 398                                 if (showerr_) {
 399                                         cerr << errdata_;
 400                                         ProgressInterface::instance()->appendError(QString::fromLocal8Bit(errdata_));
 401                                 }
 402                         }
 403                 }
 404         }
 405 }
 406
 407
 408 void SystemcallPrivate::processStarted()
 409 {
 410 #ifdef DEBUG_SYSTEMCALL
 411         cmd_ = cmd_ + " -- process: " + QString::number((quint64) proc_);
 412         if (true) {
 413 #else
 414         if (state != Running) {
 415 #endif
 416                 state = Running;
 417                 ProgressInterface::instance()->processStarted(cmd_);
 418         }
 419 }
 420
 421
 422 void SystemcallPrivate::processFinished(int, QProcess::ExitStatus)
 423 {
 424 #ifdef DEBUG_SYSTEMCALL
 425         cmd_ = cmd_ + " -- process: " + QString::number((quint64) proc_);
 426         if (true) {
 427 #else
 428         if (state != Finished) {
 429 #endif
 430                 state = Finished;
 431                 ProgressInterface::instance()->processFinished(cmd_);
 432         }
 433 }
 434
 435
 436 void SystemcallPrivate::processError(QProcess::ProcessError)
 437 {
 438         state = Error;
 439         ProgressInterface::instance()->appendError(errorMessage());
 440 }
 441
 442
 443 QString SystemcallPrivate::errorMessage() const
 444 {
 445         if (!proc_)
 446                 return "No QProcess available";
 447
 448         QString message;
 449         switch (proc_->error()) {
 450                 case QProcess::FailedToStart:
 451                         message = "The process failed to start. Either the invoked program is missing, "
 452                                       "or you may have insufficient permissions to invoke the program.";
 453                         break;
 454                 case QProcess::Crashed:
 455                         message = "The process crashed some time after starting successfully.";
 456                         break;
 457                 case QProcess::Timedout:
 458                         message = "The process timed out. It might be restarted automatically.";
 459                         break;
 460                 case QProcess::WriteError:
 461                         message = "An error occurred when attempting to write to the process-> For example, "
 462                                       "the process may not be running, or it may have closed its input channel.";
 463                         break;
 464                 case QProcess::ReadError:
 465                         message = "An error occurred when attempting to read from the process-> For example, "
 466                                       "the process may not be running.";
 467                         break;
 468                 case QProcess::UnknownError:
 469                 default:
 470                         message = "An unknown error occured.";
 471                         break;
 472         }
 473         return message;
 474 }
 475
 476
 477 QString SystemcallPrivate::exitStatusMessage() const
 478 {
 479         if (!proc_)
 480                 return "No QProcess available";
 481
 482         QString message;
 483         switch (proc_->exitStatus()) {
 484                 case QProcess::NormalExit:
 485                         message = "The process exited normally.";
 486                         break;
 487                 case QProcess::CrashExit:
 488                         message = "The process crashed.";
 489                         break;
 490                 default:
 491                         message = "Unknown exit state.";
 492                         break;
 493         }
 494         return message;
 495 }
 496
 497
 498 int SystemcallPrivate::exitCode()
 499 {
 500         if (!proc_)
 501                 return -1;
 502
 503         return proc_->exitCode();
 504 }
 505
 506
 507 QProcess* SystemcallPrivate::releaseProcess()
 508 {
 509         QProcess* released = proc_;
 510         proc_ = 0;
 511         return released;
 512 }
 513
 514
 515 void SystemcallPrivate::killProcess()
 516 {
 517         killProcess(proc_);
 518 }
 519
 520
 521 void SystemcallPrivate::killProcess(QProcess * p)
 522 {
 523         if (p) {
 524                 p->disconnect();
 525                 p->closeReadChannel(QProcess::StandardOutput);
 526                 p->closeReadChannel(QProcess::StandardError);
 527                 p->close();
 528                 delete p;
 529         }
 530 }
 531
 532
 533
 534 #include "moc_SystemcallPrivate.cpp"
 535 #endif
 536
 537 } // namespace support
 538 } // namespace lyx