Installing PHP 4.2.1 troubles on Solaris

hi am getting this error # make Making all in Zend make[1]: Entering directory `/usr/local/php-4.2.1/Zend' /bin/sh ../libtool --silent --mode=compile gcc -DHAVE_CONFIG_H -I. -I. -I../main -D_POSIX_PTHREAD_SEMANTICS -I../TSRM -g -O2 -prefer-non-pic -static -c -o zend_language_parser.lo `test -f zend_language_parser.c || echo './'`zend_language_parser.c In file included from zend_compile.h:24, from zend_language_parser.c:147: zend.h:55:19: unix.h: No such file or directory make[1]: *** [zend_language_parser.lo] Error 1 make[1]: Leaving directory `/usr/local/php-4.2.1/Zend' make: *** [all-recursive] Error 1 does any one know where i can get unix.h from?????????? I've tried to find it but have had no luck.. and got no reply to an earlier post Cheers Peter "the only dumb question is the one that wasn't asked"