question pas très élégante

alors voici une réponse pas très élégante : bonne lecture

# Du code avec coloration syntaxique
#include <QFile>
#include <syslog.h>
#ifndef QT_NO_DEBUG
 #define BASE_SYSFS "/tmp"
#else
 #define BASE_SYSFS ""
#endif
int write(const QString &filename, const QString &message);
int readyGPIO(int number, QFile &file, bool readOnly)
{
 //http://falsinsoft.blogspot.fr/2012/11/access-gpio-from-linux-user-space.html
 //echo XX > /sys/class/gpio/export
 //echo "out" > /sys/class/gpio/gpioXX/direction
 //echo 1 > /sys/class/gpio/gpioXX/value
 //cat /sys/class/gpio/gpioXX/value
 int result = write(BASE_SYSFS "/sys/class/gpio/export", QString::number(number));
 if (result == EXIT_FAILURE)
 return result;
 result = write(BASE_SYSFS "/sys/class/gpio/gpio"+QString::number(number)+"/direction"
 , readOnly ? "in" : "out");
 if (result == EXIT_FAILURE)
 return result;
#ifndef QT_NO_DEBUG
 if (file.isOpen())//should not be necessary but ...
 {
 syslog(LOG_WARNING, QObject::tr("[WARNING][%1:%2] %3: Internal error ! Please report it !")
 .arg(__LINE__)
 .arg(__FILE__)
 .arg(__FUNCTION__)
 .toUtf8().data());
 file.close();
 }
#endif
 file.setFileName(BASE_SYSFS "/sys/class/gpio/gpio"+QString::number(number)+"/value");
 if (readOnly)
 result = file.open(QIODevice::ReadOnly);
 else
 result = file.open(QIODevice::WriteOnly);
 if (!result)
 {
 syslog(LOG_ERR, QObject::tr("[ERROR][%1:%2] %3: Couldn't achieve to open %4 in %5 ! Here the error message: %6")
 .arg(__LINE__)
 .arg(__FILE__)
 .arg(__FUNCTION__)
 .arg(file.fileName())
 .arg(readOnly ? "read_only" : "write_only")
 .toUtf8().data());
 return EXIT_FAILURE;
 }
 return EXIT_SUCCESS;
}
int closeGPIO(int number, QFile &file)
{
 int result;
 file.close();
 result = write(BASE_SYSFS "/sys/class/gpio/unexport", QString::number(number));
 if (result == EXIT_FAILURE)
 return result;
 return EXIT_SUCCESS;
}
int write(const QString &filename, const QString &message)
{
 int result;
 QFile tmp;
 QByteArray msg = message.toUtf8().data();
 tmp.setFileName(filename);
 if (!tmp.open(QIODevice::WriteOnly))
 {
 syslog(LOG_ERR, QObject::tr("[CRITICAL][%1:%2] %3: Impossible to open %4 ! Here is the error message: %5")
 .arg(__LINE__)
 .arg(__FILE__)
 .arg(__FUNCTION__)
 .arg(filename)
 .arg(tmp.errorString())
 .toUtf8().data());
 return EXIT_FAILURE;
 }
 result = tmp.write(msg);
 if (result != msg.size() || !tmp.flush())
 {
 syslog(LOG_ERR, QObject::tr("[CRITICAL][%1:%2] %3: Impossible to write >%4< into %5 ! Here is the error message: %6")
 .arg(__LINE__)
 .arg(__FILE__)
 .arg(__FUNCTION__)
 .arg(QString(msg))
 .arg(filename)
 .arg(tmp.errorString())
 .toUtf8().data());
 return EXIT_FAILURE;
 }
 tmp.close();
 return EXIT_SUCCESS;
}