在一臺處理網絡支付的服務器遷移的時候，發現不能支付。

1.PHP版本為5.3.3

2.系統為Red Hat 4.1.2-54

查看apache的錯誤日志，發現是加密文件中一個函數bcmul()報錯：PHP Fatal error:  Call to undefined function bcmul() in /php_rsa.php on line xxx ,這個函數是PHP數學擴展中的一個,使用 bcscale() 來設置全局默認的小數位數，具體用法如下：

2. echo bcmul('1.34747474747', '35', 3); // 47.161  
3. echo bcmul('2', '4'); // 8  
4. ?> 

解決方法使用如下命令:yum install php-bcmath 就安裝好了,如果出現下面這種情況：

Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile  * base: mirrors.yun-idc.com  * extras: mirrors.yun-idc.com  * rpmforge: ftp.riken.jp  * updates: mirrors.yun-idc.com Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package php-bcmath.x86_64 0:5.1.6-40.el5_9 set to be updated --> Processing Dependency: php-common = 5.1.6-40.el5_9 for package: php-bcmath --> Running transaction check ---> Package php-common.x86_64 0:5.1.6-40.el5_9 set to be updated --> Processing Conflict: php53-common conflicts php-common --> Finished Dependency Resolution php53-common-5.3.3-13.el5_9.1.x86_64 from installed has depsolving problems   --> php53-common conflicts with php-common Error: php53-common conflicts with php-common  You could try using --skip-broken to work around the problem  You could try running: package-cleanup --problems                         package-cleanup --dupes   rpm -Va --nofiles --nodigest 

就需要使用yum update 之后再yum install php53-bcmath就好了,此函數在php.ini中的選項：

1. [bcmath] ; Number of decimal digits for all bcmath functions. ; http://www.php.net/manual/en/bc.configuration.php#ini.bcmath.scale bcmath.scale = 0  
2. BC //數學庫配置選項