Description:
------------
When trying to compile the php-4.3.5 code with Openserver 5.0.6A using gcc, I receive a symbol undefined error in the link phase for S_ISSOCK referenced in mail/streams.lo

In looking at the code, 

#if defined (S_ISFIFO) || defined(S_ISSOCK)

on line 2019 is where the problem is. SCO Openserver has S_ISFIFO defined but not S_ISSOCK and so the if statement is true (from the S_ISFIFO) but the code the gets ececuted below it assumes that S_ISSOCK is defined which it is not on this system.

A grep -rl S_ISSOCK *
and grep -rl S_IFSOCK * in the /usr/include directory produces nothing.

*grep -rl (recurse and list files that match).

Expected result:
----------------
The compile to complete.

Actual result:
--------------
/bin/sh /software/apache/php-4.3.5/libtool --silent --preserve-dup-deps --mode=link gcc -export-dynamic -g -O2     ext/ctype/ctype.lo ext/mysql/php_mysql.lo ext/mysql/libmysql/libmysql.lo ext/mysql/libmysql/errmsg.lo ext/mysql/libmysql/net.lo ext/mysql/libmysql/violite.lo ext/mysql/libmysql/password.lo ext/mysql/libmysql/my_init.lo ext/mysql/libmysql/my_lib.lo ext/mysql/libmysql/my_static.lo ext/mysql/libmysql/my_malloc.lo ext/mysql/libmysql/my_realloc.lo ext/mysql/libmysql/my_create.lo ext/mysql/libmysql/my_delete.lo ext/mysql/libmysql/my_tempnam.lo ext/mysql/libmysql/my_open.lo ext/mysql/libmysql/mf_casecnv.lo ext/mysql/libmysql/my_read.lo ext/mysql/libmysql/my_write.lo ext/mysql/libmysql/errors.lo ext/mysql/libmysql/my_error.lo ext/mysql/libmysql/my_getwd.lo ext/mysql/libmysql/my_div.lo ext/mysql/libmysql/mf_pack.lo ext/mysql/libmysql/my_messnc.lo ext/mysql/libmysql/mf_dirname.lo ext/mysql/libmysql/mf_fn_ext.lo ext/mysql/libmysql/mf_wcomp.lo ext/mysql/libmysql/typelib.lo ext/mysql/libmysql/safemalloc.lo ext/mysql/libmysql/my_alloc.lo ext/mysql/libmysql/mf_format.lo ext/mysql/libmysql/mf_path.lo ext/mysql/libmysql/mf_unixpath.lo ext/mysql/libmysql/my_fopen.lo ext/mysql/libmysql/mf_loadpath.lo ext/mysql/libmysql/my_pthread.lo ext/mysql/libmysql/my_thr_init.lo ext/mysql/libmysql/thr_mutex.lo ext/mysql/libmysql/mulalloc.lo ext/mysql/libmysql/string.lo ext/mysql/libmysql/default.lo ext/mysql/libmysql/my_compress.lo ext/mysql/libmysql/array.lo ext/mysql/libmysql/my_once.lo ext/mysql/libmysql/list.lo ext/mysql/libmysql/my_net.lo ext/mysql/libmysql/dbug.lo ext/mysql/libmysql/strmov.lo ext/mysql/libmysql/strxmov.lo ext/mysql/libmysql/strnmov.lo ext/mysql/libmysql/strmake.lo ext/mysql/libmysql/strend.lo ext/mysql/libmysql/strfill.lo ext/mysql/libmysql/is_prefix.lo ext/mysql/libmysql/int2str.lo ext/mysql/libmysql/str2int.lo ext/mysql/libmysql/strinstr.lo ext/mysql/libmysql/strcont.lo ext/mysql/libmysql/strcend.lo ext/mysql/libmysql/bchange.lo ext/mysql/libmysql/bmove.lo ext/mysql/libmysql/bmove_upp.lo ext/mysql/libmysql/longlong2str.lo ext/mysql/libmysql/strtoull.lo ext/mysql/libmysql/strtoll.lo ext/mysql/libmysql/charset.lo ext/mysql/libmysql/ctype.lo ext/overload/overload.lo ext/pcre/pcrelib/maketables.lo ext/pcre/pcrelib/get.lo ext/pcre/pcrelib/study.lo ext/pcre/pcrelib/pcre.lo ext/pcre/php_pcre.lo ext/posix/posix.lo ext/session/session.lo ext/session/mod_files.lo ext/session/mod_mm.lo ext/session/mod_user.lo regex/regcomp.lo regex/regexec.lo regex/regerror.lo regex/regfree.lo ext/standard/array.lo ext/standard/base64.lo ext/standard/basic_functions.lo ext/standard/browscap.lo ext/standard/crc32.lo ext/standard/crypt.lo ext/standard/cyr_convert.lo ext/standard/datetime.lo ext/standard/dir.lo ext/standard/dl.lo ext/standard/dns.lo ext/standard/exec.lo ext/standard/file.lo ext/standard/filestat.lo ext/standard/flock_compat.lo ext/standard/formatted_print.lo ext/standard/fsock.lo ext/standard/head.lo ext/standard/html.lo ext/standard/image.lo ext/standard/info.lo ext/standard/iptc.lo ext/standard/lcg.lo ext/standard/link.lo ext/standard/mail.lo ext/standard/math.lo ext/standard/md5.lo ext/standard/metaphone.lo ext/standard/microtime.lo ext/standard/pack.lo ext/standard/pageinfo.lo ext/standard/parsedate.lo ext/standard/quot_print.lo ext/standard/rand.lo ext/standard/reg.lo ext/standard/soundex.lo ext/standard/string.lo ext/standard/scanf.lo ext/standard/syslog.lo ext/standard/type.lo ext/standard/uniqid.lo ext/standard/url.lo ext/standard/url_scanner.lo ext/standard/var.lo ext/standard/versioning.lo ext/standard/assert.lo ext/standard/strnatcmp.lo ext/standard/levenshtein.lo ext/standard/incomplete_class.lo ext/standard/url_scanner_ex.lo ext/standard/ftp_fopen_wrapper.lo ext/standard/http_fopen_wrapper.lo ext/standard/php_fopen_wrapper.lo ext/standard/credits.lo ext/standard/css.lo ext/standard/var_unserializer.lo ext/standard/ftok.lo ext/standard/aggregation.lo ext/standard/sha1.lo ext/tokenizer/tokenizer.lo ext/xml/xml.lo ext/xml/expat/xmlparse.lo ext/xml/expat/xmlrole.lo ext/xml/expat/xmltok.lo TSRM/TSRM.lo TSRM/tsrm_strtok_r.lo TSRM/tsrm_virtual_cwd.lo main/main.lo main/snprintf.lo main/spprintf.lo main/php_sprintf.lo main/safe_mode.lo main/fopen_wrappers.lo main/alloca.lo main/php_scandir.lo main/php_ini.lo main/SAPI.lo main/rfc1867.lo main/php_content_types.lo main/strlcpy.lo main/strlcat.lo main/mergesort.lo main/reentrancy.lo main/php_variables.lo main/php_ticks.lo main/streams.lo main/network.lo main/php_open_temporary_file.lo main/php_logos.lo main/output.lo main/memory_streams.lo main/user_streams.lo Zend/zend_language_parser.lo Zend/zend_language_scanner.lo Zend/zend_ini_parser.lo Zend/zend_ini_scanner.lo Zend/zend_alloc.lo Zend/zend_compile.lo Zend/zend_constants.lo Zend/zend_dynamic_array.lo Zend/zend_execute_API.lo Zend/zend_highlight.lo Zend/zend_llist.lo Zend/zend_opcode.lo Zend/zend_operators.lo Zend/zend_ptr_stack.lo Zend/zend_stack.lo Zend/zend_variables.lo Zend/zend.lo Zend/zend_API.lo Zend/zend_extensions.lo Zend/zend_hash.lo Zend/zend_list.lo Zend/zend_indent.lo Zend/zend_builtin_functions.lo Zend/zend_sprintf.lo Zend/zend_ini.lo Zend/zend_qsort.lo Zend/zend_multibyte.lo Zend/zend_execute.lo sapi/cli/php_cli.lo sapi/cli/getopt.lo main/internal_functions_cli.lo -lm -lsocket  -o sapi/cli/php
Undefined			first referenced
symbol  			    in file
S_ISSOCK                            main/streams.lo
ERROR: Symbol referencing errors. No output written to sapi/cli/php
collect2: ld returned 1 exit status
make: *** [sapi/cli/php] Error 1