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eekhoorn12
15th October 2007, 23:45
Hey

I have a problem with a program i am trying to create. For the program i need to read a file and convert what i read to ascii codes so i can manipulate it. I have suceded into reading the file and converting a part of the data to ascii values but at some characters i get 0 values. The file i test it with is a file i created with a hex editer in which i typed al the hex values from 0 to FF. The problem lies in the extended ascii characters. I have attached my test file i is a simple file with no extension.

Here is the code i use:

#include <QApplication>
#include <QtGui>
#include "yenc.h"

Yenc::Yenc(QWidget *parent)
: QDialog(parent)
{

QPushButton *connect = new QPushButton("Hello Qt!");
QPushButton *list = new QPushButton("Hello Qt!");
lineEdit = new QLineEdit;
textbox = new QTextEdit("test");

QObject::connect(connect, SIGNAL(clicked()), this, SLOT(buttonClicked()));
QObject::connect(list, SIGNAL(clicked()), this, SLOT(textboxClear()));

QHBoxLayout *layout = new QHBoxLayout;

layout->addWidget(connect);
layout->addWidget(list);
layout->addWidget(lineEdit);
layout->addWidget(textbox);
setLayout(layout);
setWindowTitle(tr("Test"));
}

int Yenc::buttonClicked()
{
QString readstring;
qint64 asciival;

QFile file(lineEdit->text());
if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
{
return 0;
}

QTextStream out(&file);

while(!out.atEnd())
{
readstring = out.read(1);
asciival = readstring.at(0).toAscii();

if(asciival < 0)
{
asciival = asciival + 256;
}

textbox->append(QString::number(asciival));
}
}

int Yenc::textboxClear()
{
textbox->clear();
}


Hope someone can help me

Thanks
Marcel

high_flyer
16th October 2007, 00:14
The problem lies in the extended ascii characters.
Could you explain WHAT the problem is?

eekhoorn12
16th October 2007, 00:41
Well every character has a specific value. The ascii table including the extended ascii ranges from decimal value 0 to decimal value 255, as you can see here http://www.asciitable.com/

I have created a file with al of those values. That file i read with my application and convert every character to it's corresponding decimal value and display it in a textbox. For the first 127 characters everything works but when the extended characters appear they aren't al recognized and converted correctly. Instead of it's corresponding decimal value it returns a zero and that isn't the value i want.

ChristianEhrlicher
16th October 2007, 07:48
Don't use QString but QByteArray to read your data to avoid conversion to QString.
Use QByteArray::read() (http://doc.trolltech.com/4.3/qiodevice.html#read-2) or QByteArray::readAll() (http://doc.trolltech.com/4.3/qiodevice.html#readAll)

eekhoorn12
16th October 2007, 18:33
Don't use QString but QByteArray to read your data to avoid conversion to QString.
Use QByteArray::read() (http://doc.trolltech.com/4.3/qiodevice.html#read-2) or QByteArray::readAll() (http://doc.trolltech.com/4.3/qiodevice.html#readAll)

Thanks got it working now.

eekhoorn12
17th October 2007, 14:59
Oke i have got another question.
What i am trying to create is a yenc encoding. Know that i have solved my previous problem i've got the encoding working but i also need a crc32 check.

I have a working code to generate crc but the result is wrong but i don't know why.
I use the same example file as in my first post and the crc code i get is 9a749b3b but the code i should be getting is 29058C73.

Here is my source:

#include <QApplication>
#include <QtGui>
#include "yenc.h"

int crc_val;
long crc_anz;
int crc_val2;

Yenc::Yenc(QWidget *parent)
: QDialog(parent)
{

QPushButton *connect = new QPushButton("Hello Qt!");
QPushButton *list = new QPushButton("Hello Qt!");
lineEdit = new QLineEdit;
textbox = new QTextEdit("test");

QObject::connect(connect, SIGNAL(clicked()), this, SLOT(buttonClicked()));
QObject::connect(list, SIGNAL(clicked()), this, SLOT(textboxClear()));

QHBoxLayout *layout = new QHBoxLayout;

layout->addWidget(connect);
layout->addWidget(list);
layout->addWidget(lineEdit);
layout->addWidget(textbox);
setLayout(layout);
setWindowTitle(tr("Test"));
}

int Yenc::buttonClicked()
{
QByteArray ReadData, ReadHex;
qint64 AsciiVal;
QString bla2;
QString output;
bool ok;
unsigned char c;


QFile file(lineEdit->text());
if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
{
return 0;
}

CrcInit();

while(!file.atEnd())
{
for(int i = 0; i < 16; i++)
{
ReadData = file.read(1);
char *data = ReadData.data();
ReadHex = ReadData.toHex();
AsciiVal = ReadHex.toInt(&ok, 16);
if(ok != true)
{
textbox->append("Conversion failed");
}
else
{
c = *data;
CrcAdd(c);
AsciiVal = ( AsciiVal + 42 ) % 256;
switch (AsciiVal)
{
case 0:
case 9:
case 10:
case 13:
case 61:
case 46:
AsciiVal = AsciiVal + 64 ;
}
output.append(QString::number(AsciiVal));
output.append(" ");
}
//textbox->append(QString::number(asciival));
}
textbox->append(output);
output = "";
}
bla2.sprintf("0x%lx",crc_val ^ 0xFFFFFFFF);
textbox->append(bla2);
return 0;
}

int Yenc::textboxClear()
{
textbox->clear();
return 0;
}

qint64 crc_tab[256] =
{
0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
}
;

void Yenc::CrcInit()
{
crc_val = -1L ;
crc_anz = 0L;
}

void Yenc::CrcAdd(int c)
{
qint64 ch1,ch2,cc;

cc= (c) & 0x000000ffL;

ch1=(crc_val ^ cc) & 0xffL;

ch1=crc_tab[ch1];

ch2=(crc_val>>8L) & 0xffffffL; // Correct version

crc_val=ch1 ^ ch2;

crc_anz++;
}


Hope someone can help me again