ipe if <tt>zpipe -d</tt> is used.  If any other
arguments are provided, no compression or decompression is performed.  Instead a usage
message is displayed.  Examples are <tt>zpipe < foo.txt > foo.txt.z</tt> to compress, and
<tt>zpipe -d < foo.txt.z > foo.txt</tt> to decompress.
<pre><b>
/* compress or decompress from stdin to stdout */
int main(int argc, char **argv)
{
    int ret;

    /* avoid end-of-line conversions */
    SET_BINARY_MODE(stdin);
    SET_BINARY_MODE(stdout);

    /* do compression if no