How to display the content of an ELF file in QTextEdit? - qt

Question

I need to display all the bytes from and ELF file to a QTextEdit and i did not find any reasonable way to do this. I could print maximum "?ELF??" then nothing. The content of the ELF is read in a char* array (this is a requirement, can't change that) and yes, for sure the content is read.

Answer 1

I am guessing that your code looks something like this:
char *elf = ReadElfFile();
QString str(elf); // Constructs a string initialized with the 8-bit string str.
QTextEdit edit(str);
The problem is that QString constructor will stop on first NUL character, and the ELF file is full of them.
If you want to make a QString that contains NULs, do something like this:
QString str(QByteArray(elf, length_of_elf));

Answer 2

This just nearly broke me too, so I'll post my solution to anyone interested.
Let's say I have a QByteArray data that is filled like so
data += file.readAll();
I'll then invoke an update of the QTextEdit where I'll do
QByteArray copy = data;
QString text = copy.replace((char)0x00, "\\0");
textEdit.setPlainText(text);
This way, all null bytes in the data will be displayed as the printable string \0.
Since I want changes of the textEdit to be reflected in my data, I have to parse this back using
QByteArray hex = textEdit.toPlainText().toUtf8().toHex().toUpper();
hex.replace("5C30", "00");
hex.replace("5C00", "5C30"); // oops, was escaped
data = QByteArray::fromHex(hex);
I'm using the hex format because I just could not get the replace to work with null byte characters. The code above first replaces all occurrences of the string \0 with null bytes in the data. Then it replaces any \ followed by a null byte back with \0 - which essentially means \\0 becomes \0.
It's not very elegant, but maybe it helps anyone ending up here to move on in the right direction. If you have improvements, please comment.