How to write 0x00 into file

Question

I'm writing some application which will communicate (write only) with my custom USB-serial device. It is Cocoa (OS X) application and part which is related to this writing is coded in POSIX style.

I have solved mostly all things but have issues with NULL (0x00) character.

For example lets says that I need to white 5 characters to a file.

My code is as follow:

char stringAsChar[5];

stringAsChar[0] = 0x77;
stringAsChar[1] = 0x44;
stringAsChar[2] = 0x00; //here is an problem
stringAsChar[3] = 0x05;
stringAsChar[4] = 0xFF;
...
fputs(stringAsChar, file); // write to file

Each character at specified index represents data for some registers into target device.

The problem arise when stream include 0x00 character which i need to have as data, writing is stopped there (0x00 interpreted as stop of stream).

How to overcome this issue?

Answer 1

Try using fwrite instead. It lets you specify the amount of bytes written to the stream. Or loop over your characters and use fputc.

Answer 2

fputs works with NUL-terminated strings. If you want to write NUL characters to a file you can use fwrite instead:

noOfBytesWritten = fwrite(stringAsChar, 1, noOfBytesToWrite, file);