今天在linux上面智障一般搞了好久，本來想安裝個swoole的，然后用 php -m 的命令想看下安裝的PHP擴展庫，發現有的擴展庫有的可以出來，有的加載失敗，
加載失敗的錯誤類型：
PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/memcached.so' - /usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/memcached.so: undefined symbol: zend_new_interned_string in Unknown on line 0
如下：
[root@pys /]# php -m PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/memcached.so' - /usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/memcached.so: undefined symbol: zend_new_interned_string in Unknown on line 0 PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/swoole.so' - /usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/swoole.so: undefined symbol: zend_new_interned_string in Unknown on line 0 PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/redis.so' - /usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/redis.so: undefined symbol: zend_new_interned_string in Unknown on line 0 PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/curl.so' - /usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/curl.so: cannot open shared object file: No such file or directory in Unknown on line 0 PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/fileinfo.so' - /usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/fileinfo.so: cannot open shared object file: No such file or directory in Unknown on line 0 PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/gd.so' - /usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/gd.so: cannot open shared object file: No such file or directory in Unknown on line 0 PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/json.so' - /usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/json.so: cannot open shared object file: No such file or directory in Unknown on line 0 PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/phar.so' - /usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/phar.so: cannot open shared object file: No such file or directory in Unknown on line 0 PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/zip.so' - /usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/zip.so: cannot open shared object file: No such file or directory in Unknown on line 0 [PHP Modules] bz2 calendar Core ctype date ereg exif filter ftp gettext gmp
上面的意思是 ：找不到擴展庫的路徑； 這是為什么尼？不是有的擴展庫也可以出來嗎？
然后我是百度上找各種答案，並不能解決我的問題，最后自己發現問題所在：
因為我並沒有為所有的擴展庫加了快捷鏈接，以為在哪里只要用 php -m 的命令就可以查看所有的擴展庫。
其實是要：/usr/local/php7/bin/php -m 這個命令才可以，我的是PHP7.0版本的，其他版本自己換下這個路徑就好。
如此，就可以看到所有的擴展庫了：
[root@pys bin]# /usr/local/php7/bin/php -m [PHP Modules] bcmath Core ctype curl date dom fileinfo filter ftp gd gettext hash iconv json libxml mbstring mcrypt memcached mysqli mysqlnd openssl pcntl pcre PDO pdo_mysql pdo_sqlite Phar posix redis Reflection session shmop SimpleXML soap sockets SPL sqlite3 standard swoole sysvsem tokenizer xml xmlreader xmlrpc xmlwriter zip zlib [Zend Modules]