今天在linux上面智障一般搞了好久，本來想安裝個swoole的，然後用 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； 這是為什麽尼？不是有的擴展庫也可以出來嗎？

然後我是百度上找各種答案，並不能解決我的問題，最後自己發現問題所在：

因為我並沒有為所有的擴展庫加了快捷鏈接，以為在哪裏只要用 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]

PHP啟動：動態庫加載失敗（PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php7/lib/php/extensions/no-debug-non-zts-20151012/*.so'）