using libtar library in c

Question

I am trying to make a tar file using c. For a reason I can not use

system("tar -cvf xxxx.tar xxxx");

my code is:

#include <stdio.h>
#include <libtar.h>
#include <fcntl.h>

int main(void) {

        TAR *pTar;

        char *tarFilename = "file.tar";
        char *srcDir = "directory";

        char *extractTo = ".";
        tar_open(&pTar, tarFilename, NULL, O_WRONLY | O_CREAT, 0644, TAR_GNU);
        tar_append_tree(pTar, srcDir, extractTo);
        tar_close(pTar);
        return (0);

}

After running this code, when I want to untar with

tar -xvf file.tar

I am getting an error

tar: This does not look like a tar archive
tar: Exiting with failure status due to previous errors

What is the problem with my c code ?

Answer 1

I think you need to call tar_append_eof http://linux.die.net/man/3/tar_append_eof before closing the tar file.

The tar_append_eof() function writes an EOF marker (two blocks of all zeros) to the tar file associated with t.