Unzipping a file to disk using libzip

I'm trying to unzip an executable file using c++ and the libzip library. Starting with the answer by rodrigo on a similar question, I come to this sample code:

#include <zip.h>
int main()
{
    //Open the ZIP archive
    int err = 0;
    zip *z = zip_open("foo.zip", 0, &err);

    //Search for the file of given name
    const char *name = "file.txt";
    struct zip_stat st;
    zip_stat_init(&st);
    zip_stat(z, name, 0, &st);

    //Alloc memory for its uncompressed contents
    char *contents = new char[st.size];

    //Read the compressed file
    zip_file *f = zip_fopen(z, "file.txt", 0);
    zip_fread(f, contents, st.size);
    zip_fclose(f);

    //And close the archive
    zip_close(z);
}

from what I understand, this code does work to unzip a file, but I do not know how to write that file to the disk, much like extracting a zip file would so using a tool like winzip does. Having the unzipped data in memory doesn't help me, but I've been unable to figure out how to actually get the files onto the disk.

Something like this should do it:

if(!std::ofstream("file1.txt").write(contents, st.size))
{
    std::cerr << "Error writing file" << '\n';
    return EXIT_FAILURE;
}

Look up std::ofstream.

Of course you should check all your zip file functions to see if they returned errors before proceeding.