Passes the name of an image to be activated in a child process.
    This function is nonreentrant.
    Format
      #include  <unistd.h>
      int execv  (char *file_spec, char *argv[]);
1 – Arguments
 file_spec
    The full file specification of a new image to be activated in the
    child process.
 argv
    An array of pointers to null-terminated character strings.
    These strings constitute the argument list available to the new
    process. By convention, argv[0] must point to a string that is
    the same as the new process filename (or its last component).
    argv is terminated by a NULL pointer.
2 – Description
See execl for a description of how the exec functions operate.
3 – Return Value
-1 Indicates failure.