引言
今天在教别人使用protobuf的时候，无意中发现了一个php cli模式下的诡异问题，费了老半天的找到解决方法了，这里拿出来分享下。
问题描述
我们这边最先引入了protobuf协议，使用的是allegro/php-protobuf这个扩展安装的。这几天其他同事也要用到这个，于是我将protobuf生成php类库文件的部分放到了一个公共的位置/data/php_proto/文件夹下，里面有这些内容，
drwsrwxr-x 2 yanruitao users 4096 10月 14 17:05 Dmp
-rwxrwxr-x 1 yanruitao users 472 10月 10 17:59 dmp.proto
drwsrwxr-x 2 yanruitao users 4096 10月 10 17:54 ProtobufCompiler
-rwxrwxr-x 1 yanruitao users 2969 3月 9 2015 protoc-php.php
后面两个是必须的，生成pb协议实现类库文件时会用到，前面两个是一个简单的例子，使用也很简单，就像下面这样。
php protoc-php.php -n --psr dmp.proto //-n是使用命名空间，--psr是使用psr-4标准
等同事用的时候发现会报错，
PHP Warning: file_put_contents(pb_proto_dmp.php): failed to open stream: Permission denied in /data/php_proto/ProtobufCompiler/ProtobufParser.php on line 309
同事问我的时候我直接说，加上sudo就可以了，结果加上sudo问题更严重了，本来装好的扩展程序加载不成功，经过一番排查发下有下面这么一个问题：
$yanruitao: php -i | grep 'php.ini'
$yanruitao: sudo php -i | grep 'php.ini'
两种用户加载的不是同一个配置文件，普通用户加载的是/usr/local/php/lib/php.ini，而root用户加载的是/etc/php.ini这个文件，我看了下这两个文件内容不一致，哈哈，好开心，赶紧把先把/etc/php.ini备份，/usr/local/php/lib/php.ini复制到/etc/php.ini，复制完了之后，我再使用的时候吓我一跳，报了一大堆错误:
PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/web_stub_cntl.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/web_stub_cntl.so: undefined symbol: zend_new_interned_string in Unknown on line 0
Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/web_stub_cntl.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/web_stub_cntl.so: undefined symbol: zend_new_interned_string in Unknown on line 0
PHP Warning: PHP Startup: test: Unable to initialize module
Module compiled with module API=20100525
PHP compiled with module API=20090626
These options need to match
in Unknown on line 0
Warning: PHP Startup: test: Unable to initialize module
Module compiled with module API=20100525
PHP compiled with module API=20090626
These options need to match
in Unknown on line 0
PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/protobuf.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/protobuf.so: undefined symbol: zend_new_interned_string in Unknown on line 0
Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/protobuf.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/protobuf.so: undefined symbol: zend_new_interned_string in Unknown on line 0
PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/imagick.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/imagick.so: undefined symbol: zend_new_interned_string in Unknown on line 0
Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/imagick.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/imagick.so: undefined symbol: zend_new_interned_string in Unknown on line 0
PHP Warning: PHP Startup: Unable to load dynamic library '/data/boss/phpredis-develop/modules/redis.so' - /data/boss/phpredis-develop/modules/redis.so: undefined symbol: zend_new_interned_string in Unknown on line 0
Warning: PHP Startup: Unable to load dynamic library '/data/boss/phpredis-develop/modules/redis.so' - /data/boss/phpredis-develop/modules/redis.so: undefined symbol: zend_new_interned_string in Unknown on line 0
PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/curl.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/curl.so: cannot open shared object file: No such file or directory in Unknown on line 0
Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/curl.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/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/php/lib/php/extensions/no-debug-non-zts-20100525/fileinfo.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/fileinfo.so: cannot open shared object file: No such file or directory in Unknown on line 0
Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/fileinfo.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/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/php/lib/php/extensions/no-debug-non-zts-20100525/gd.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/gd.so: cannot open shared object file: No such file or directory in Unknown on line 0
Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/gd.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/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/php/lib/php/extensions/no-debug-non-zts-20100525/json.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/json.so: cannot open shared object file: No such file or directory in Unknown on line 0
Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/json.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/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/php/lib/php/extensions/no-debug-non-zts-20100525/phar.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/phar.so: cannot open shared object file: No such file or directory in Unknown on line 0
Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/phar.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/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 '/data/boss/phpredis-develop/modules/redis.so' - /data/boss/phpredis-develop/modules/redis.so: undefined symbol: zend_new_interned_string in Unknown on line 0
Warning: PHP Startup: Unable to load dynamic library '/data/boss/phpredis-develop/modules/redis.so' - /data/boss/phpredis-develop/modules/redis.so: undefined symbol: zend_new_interned_string in Unknown on line 0
PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/zip.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/zip.so: cannot open shared object file: No such file or directory in Unknown on line 0
Warning: PHP Startup: Unable to load dynamic library '/usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/zip.so' - /usr/local/php/lib/php/extensions/no-debug-non-zts-20100525/zip.so: cannot open shared object file: No such file or directory in Unknown on line 0
protoc-php.php requires protobuf extension installed to run
这让我摸不着头脑了。
时间过去了好久，没有发现任何突破，却发现了一个备用的解决这个问题的方案，修改/data/php_proto/文件夹权限为0775，其他普通用户就可以直接使用了，不用加sudo(这个是我的错，忘记修改文件夹权限了，这也让我发现了这个诡异的问题)
chmod -R 0775 /data/php_proto
看了报的这些错误，大部分都是扩展的问题，有的是扩展加载不成功，有的是扩展不存在，我就纳闷了，为什么普通用户可以，root用户就不可以。
看到root用户php -i的时候，配置文件的地方跟非root用户有不一致的地方：
//非root
Scan this dir for additional .ini files => (none)
Additional .ini files parsed => (none)
//root
Scan this dir for additional .ini files => /etc/php.d
Additional .ini files parsed => /etc/php.d/curl.ini,
......
命名加载的是一样的配置文件怎么加载之后的内容就不一样呢？
搜了半天，知道了报的错里面有部分是跟这个有关系的，但是这个在哪里修改搜了老久也没有搜到。
忽然想到root用户和非root用户使用的php可执行文件是不一致的
root => /usr/bin/php
非root => /usr/local/bin/php
尝试着对这两个文件使用了php -v，结果下了我一跳，root用户的版本是5.3.3，非root用户是5.4.6，呵呵，我就呵呵了，谁部署的环境~，坑人啊。
尝试着将原有/usr/bin/php备份后，复制/usr/local/bin/php过来覆盖掉，在使用php -v发现版本一致了，也不报错了，再次去执行php protoc-php.php -n --psr dmp.proto，发现all is well，至此问题解决。
纠结了半天，结果就是版本的问题。
总结
多思考，多换个角度思考。
做事要完善啊，别给后辈留下一些诡异问题←_←。