zip_fread —
read from file
#include <zip.h>
zip_int64_t
  
  zip_fread(zip_file_t
    *file, void *buf,
    zip_uint64_t nbytes);
The zip_fread() function reads up to
  nbytes bytes from file into
  buf from the current position in the file (see
  zip_fseek(3)). After reading, the
  current position is updated by the number of bytes read.
If successful, the number of bytes actually read is returned. When
  zip_fread() is called after reaching the end of the
  file, 0 is returned. In case of error, -1 is returned.
zip_fread() was added in libzip 0.6. In libzip 0.10 the
  return type was changed from ssize_t to
  zip_int64_t. In libzip 0.10 the type of
  nbytes was changed from size_t to
  zip_uint64_t.