Code to Generate a Version Number Header (2)

I have recently switched to using Mercurial (Hg) as my version control system of choice so have updated my little tool used to generate a version number header file that other projects can include. I have included both the local and global Hg revision numbers plus I've added an inline function to return the version number as a string. As before, the version number includes the major, minor and daily build numbers. I display the global Hg revision number in my About dialogs in the same way as Qt Creator does (the global Hg revision number is a string).

A typical version header now looks like this:

#ifndef VERSION_H

#define VERSION_H

namespace Version

{

const int MAJOR = 1;

const int MINOR = 6;

const int LOCAL_REVISION = 46;

const int BUILD = 16130;

inline const char* versionString()

{

return "1.6.46.16130";

}

inline const char* globalRevision()

{

return "81a3662fbc71";

}

}

#endif // VERSION_H

The code that produces the header looks like this (apologies for the formatting - the online source code formatter isn't working today):

#include <iostream>

#include <QProcess>

#include <QStringList>

#include <QFile>

#include <QTextStream>

#include <QDate>

#include <QTime>

#include <QFileInfo>

#include <QTemporaryFile>

#include <QtGlobal>

#include <cstdlib>

namespace

{

int getBuildNumber()

{

const QDate today(QDate::currentDate());

return ((today.year() - 1994) * 1000) + today.dayOfYear();

}

int getLocalHgRevision()

{

int revision = 0;

QProcess process;

process.start("hg", QStringList() << "id" << "-n");

if (process.waitForStarted() && process.waitForReadyRead())

{

revision = atoi(process.readAll().constData());

process.waitForFinished();

}

return revision;

}

QString getGlobalHgRevision()

{

QString revision = "";

QProcess process;

process.start("hg", QStringList() << "id" << "-i");

if (process.waitForStarted() && process.waitForReadyRead())

{

revision = QString(process.readAll().constData()).trimmed();

revision.remove('+');

process.waitForFinished();

}

return revision;

}

QByteArray readFile(const QString& fileName)

{

QFile file(fileName);

if (!file.open(QIODevice::ReadOnly))

{

return QByteArray();

}

return file.readAll();

}

int writeFile(const QString& fileName, const int major, const int minor, const int localRevision,

const int buildNumber, const QString& globalRevision)

{

// Create a temp file containing the version info and

// only replace the existing one if they are different

QTemporaryFile tempFile;

if (tempFile.open())

{

QTextStream out(&tempFile);

out << "#ifndef VERSION_H\r\n";

out << "#define VERSION_H\r\n\r\n";

out << "namespace Version\r\n";

out << "{\r\n";

out << "\tconst int MAJOR = " << major << ";\r\n";

out << "\tconst int MINOR = " << minor << ";\r\n";

out << "\tconst int LOCAL_REVISION = " << localRevision << ";\r\n";

out << "\tconst int BUILD = " << buildNumber << ";\r\n\r\n";

out << "\tinline const char* versionString()\r\n";

out << "\t{\r\n";

out << "\t\treturn \"" << major << '.' << minor << '.' << localRevision << '.' << buildNumber << "\";\r\n";

out << "\t}\r\n\r\n";

out << "\tinline const char* globalRevision()\r\n";

out << "\t{\r\n";

out << "\t\treturn \"" << globalRevision << "\";\r\n";

out << "\t}\r\n";

out << "}\r\n\r\n";

out << "#endif // VERSION_H\r\n";

const QString tempFileName = tempFile.fileName();

tempFile.close();

if (!QFile::exists(fileName) || readFile(fileName) != readFile(tempFileName))

{

QFile::remove(fileName);

QFile::copy(tempFileName, fileName);

}

return 0;

}

else

{

std::cout << "Error creating temporary file!" << std::endl;

return 1;

}

}

}

int main(int argc, char *argv[])

{

if (argc != 4)

{

std::cout << "Usage: version major minor filename" << std::endl;

return 1;

}

const int major = atoi(argv[1]);

const int minor = atoi(argv[2]);

const int localRevision = getLocalHgRevision();

const QString globalRevision = getGlobalHgRevision();

const int buildNumber = getBuildNumber();

std::cout << major << '.' << minor << '.' << localRevision << '.' << buildNumber;

std::cout << ' ' << qPrintable(globalRevision) << std::endl;

return writeFile(argv[3], major, minor, localRevision, buildNumber, globalRevision);

}