在装ＰＨＰ的时候，有时候在设置完扩展路径，并且把ＰＨＰ下的ＥＸＴ或者ＤＬＬ目录下的.dll复制到
system32/system目录下，重新启动ＡＰＡＣＨＥ后，还是会提示某个ＤＬＬ找不到．实际上，除了路径
的设置问题以外，比如ＰＨＰ．ＩＮＩ的extension_dir等以外，ＰＨＰ的扩展组件还依赖于其他一些文件，
也要保证这些依赖文件的存在才能正确运行．以下为扩展依赖：
php_curl.dll CURL, Client URL library functions Requires: libeay32.dll, ssleay32.dll (bundled)php_domxml.dll DOM XML functions PHP <= 4.2.0 requires: libxml2.dll(bundled) PHP >= 4.3.0 requires: iconv.dll (bundled)php_fdf.dll FDF: Forms Data Format functions. Requires: fdftk.dllgnu_gettext.dll (bundled), PHP >= 4.2.3 requires libintl-1.dll,php_iconv.dll ICONV characterset conversion Requires: iconv-1.3.dllphp_ingres.dll Ingres II functions Requires: Ingres II librariesphp_interbase.dll InterBase functions Requires: gds32.dll (bundled)php_java.dll Java functions PHP <= 4.0.6 requires: jvm.dll (bundled)php_ldap.dll LDAP functions PHP <= 4.2.0 requires libsasl.dll(bundled),PHP >= 4.3.0 requires libeay32.dll,ssleay32.dll (bundled)php_mcrypt.dll Mcrypt Encryption functions Requires: libmcrypt.dllphp_mhash.dll Mhash functions PHP >= 4.3.0 requires: libmhash.dll (bundled)php_mcrypt.dll Mcrypt Encryption functions Requires: libmcrypt.dllphp_mhash.dll Mhash functions PHP >= 4.3.0 requires: libmhash.dll (bundled)php_msql.dll mSQL functions Requires: msql.dll (bundled)php_mssql.dll MSSQL functions Requires: ntwdblib.dll (bundled)php_mysql.dll MySQL functions PHP >= 5.0.0, requires libmysql.dll (bundled)php_mysqli.dll MySQLi functions PHP >= 5.0.0, requires libmysqli.dll (bundled)php_oci8.dll Oracle 8 functions Requires: Oracle 8.1+ client librariesphp_openssl.dll OpenSSL functions Requires: libeay32.dll (bundled)php_oracle.dll Oracle functions Requires: Oracle 7 client librariesphp_sybase_ct.dll Sybase functions Requires: Sybase client librariesphp_xmlrpc.dll XML-RPC functions PHP >= 4.2.1 requires: iconv.dll (bundled)php_xslt.dll XSLT functions PHP <= 4.2.0 requires sablot.dll, expat.dll (bundled).PHP >= 4.2.1 requires sablot.dll, expat.dll, iconv.dll (bundled).
