I have sybase-common-11.9.2 and sybase-openclient installed.

These lib is used to access mssql server. Why not use FreeTDS? Because FreeTDS has some problem on multibyte char I/O.

PHP configure options:

./configure \
--with-mysql=/usr \
--with-apache=../apache_1.3.27 \
--with-config-file-path=/etc/httpd \
--with-gd \
--enable-gd-native-ttf \
--with-ttf \
--with-gettext=/usr \
--enable-track-vars \
--enable-trans-sid \
--enable-inline-optimization \
--disable-debug \
--enable-ftp \
--with-zlib-dir=/usr \
--with-jpeg-dir=/usr \
--with-png-dir=/usr \
--with-freetype-dir=/usr \
--enable-mbstring \
--with-mbstring=cn \
--with-mbstring=tw \
--enable-mbregex \
--with-sybase=/opt/sybase-11.9.2 \
--with-iconv=/usr

Configure is passed. Failure when I use these options to make:

/bin/sh /usr/local/src/web/php-4.3.2/libtool --silent --preserve-dup-deps --mode=link gcc -export-dynamic -g -O2  -rdynamic -L/opt/sybase-11.9.2/lib  -R /opt/sybase-11.9.2/lib ext/zlib/zlib.lo ext/zlib/zlib_fopen_wrapper.lo ext/ctype/ctype.lo ext/ftp/php_ftp.lo ext/ftp/ftp.lo ext/gd/gd.lo ext/gd/gdttf.lo ext/gd/libgd/gd.lo ext/gd/libgd/gd_gd.lo ext/gd/libgd/gd_gd2.lo ext/gd/libgd/gd_io.lo ext/gd/libgd/gd_io_dp.lo ext/gd/libgd/gd_io_file.lo ext/gd/libgd/gd_ss.lo ext/gd/libgd/gd_io_ss.lo ext/gd/libgd/gd_png.lo ext/gd/libgd/gd_jpeg.lo ext/gd/libgd/gdxpm.lo ext/gd/libgd/gdfontt.lo ext/gd/libgd/gdfonts.lo ext/gd/libgd/gdfontmb.lo ext/gd/libgd/gdfontl.lo ext/gd/libgd/gdfontg.lo ext/gd/libgd/gdtables.lo ext/gd/libgd/gdft.lo ext/gd/libgd/gdcache.lo ext/gd/libgd/gdkanji.lo ext/gd/libgd/wbmp.lo ext/gd/libgd/gd_wbmp.lo ext/gd/libgd/gdhelpers.lo ext/gd/libgd/gd_topal.lo ext/gd/libgd/gd_gif_in.lo ext/gd/libgd/xbm.lo ext/gettext/gettext.lo ext/iconv/iconv.lo ext/mbstring/mbfilter_ja.lo ext/mbstring/mbfilter_cn.lo ext/mbstring/mbfilter_tw.lo ext/mbstring/mbfilter_kr.lo ext/mbstring/mbfilter_ru.lo ext/mbstring/mbfilter.lo ext/mbstring/mbstring.lo ext/mbstring/mbregex.lo ext/mbstring/php_mbregex.lo ext/mbstring/html_entities.lo ext/mbstring/php_unicode.lo ext/mysql/php_mysql.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 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/sybase/php_sybase_db.lo ext/tokenizer/tokenizer.lo ext/xml/xml.lo ext/xml/expat/xmlparse.lo ext/xml/expat/xmlrole.lo ext/xml/expat/xmltok.lo regex/regcomp.lo regex/regexec.lo regex/regerror.lo regex/regfree.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 -lcrypt -lsybdb -lcrypt -lmysqlclient -liconv -lfreetype -lpng -lz -ljpeg -lz -lresolv -lm -ldl -lnsl -lcrypt -lcrypt  -o sapi/cli/php
ext/sybase/php_sybase_db.o(.text+0x634): In function `php_sybase_do_connect':
/usr/local/src/web/php-4.3.2/ext/sybase/php_sybase_db.c:491: undefined reference to `dbopen'
ext/sybase/php_sybase_db.o(.text+0x70f):/usr/local/src/web/php-4.3.2/ext/sybase/php_sybase_db.c:453: undefined reference to `dbopen'
ext/sybase/php_sybase_db.o(.text+0x895):/usr/local/src/web/php-4.3.2/ext/sybase/php_sybase_db.c:544: undefined reference to `dbopen'
collect2: ld returned 1 exit status
make: *** [sapi/cli/php] Error 1

When use option 'sybase-ct', it is fails too.

When I disable cli by using --disable-cli, configure and compile is passed.

Then I change dir to Apache's source to compile it. Configure option list below:

./configure \
--prefix=/etc/httpd \
--activate-module=src/modules/php4/libphp4.a \
--enable-module=so \
--enable-module=rewrite \
--enable-module=include \
--sysconfdir=/etc/httpd

Failure at:

Configuring for Apache, Version 1.3.27
 + using installation path layout: Apache (config.layout)
 + activated php4 module (modules/php4/libphp4.a)
Creating Makefile
Creating Configuration.apaci in src
Creating Makefile in src
 + configured for Linux platform
 + setting C compiler to gcc
 + setting C pre-processor to gcc -E
 + checking for system header files
 + adding selected modules
    o rewrite_module uses ConfigStart/End
 + using -lgdbm for DBM support
      enabling DBM support for mod_rewrite
    o php4_module uses ConfigStart/End
 + using builtin Expat
 + using -ldl for vendor DSO support
 + checking sizeof various data types
 + doing sanity check on compiler and options
** A test compilation with your Makefile configuration
** failed.  The below error output from the compilation
** test will give you an idea what is failing. Note that
** Apache requires an ANSI C Compiler, such as gcc. 

======== Error Output for sanity check ========
cd ..; gcc  -DLINUX=22 -I/usr/include/gdbm -DUSE_EXPAT -I./lib/expat-lite `./apaci`     -o helpers/dummy helpers/dummy.c   -Wl,-rpath,/opt/sybase-11.9.2/lib  -rdynamic -L/opt/sybase-11.9.2/lib -Lmodules/php4 -L../modules/php4 -L../../modules/php4 -lmodphp4    -rdynamic -L/opt/sybase-11.9.2/lib -lcrypt   -lsybdb -lcrypt -lmysqlclient -liconv -lfreetype -lpng -lz -ljpeg -lz -lresolv -lm -ldl -lnsl  -lcrypt -lcrypt   -lm -lcrypt -lgdbm -ldl
/opt/sybase-11.9.2/lib/libsybdb.so: undefined reference to `__ctype_b'
/opt/sybase-11.9.2/lib/libsybdb.so: undefined reference to `__ctype_tolower'
collect2: ld returned 1 exit status
make: *** [dummy] Error 1
============= End of Error Report =============

 Aborting!

btw: ld.so.conf has the correct sybase lib path.