how to make tarrball from qt ?

I use linux , and most of the application comes in tarball like package.tar.gz,how to make these compressed package from qt ??

You could use zlib and libtar (or something similar) to handle the data in-program or, because you are on Linux, use QProcess to execute the standard tar/gzip utilities. The TAR file format is quite simple, so you could write your own TAR handler in conjunction with zlib (or the qUncompress() function with some fiddling). Other compression options will require other libraries.