一些不常见但很有用的php函数
exec(string $command[,array &$output[,int &$return_var]])
–Execute an external program
string escapeshellarg(string $arg);
string escapeshellcmd(string $command);
void passthru(string $command[,int &$return_va])
–Execute an external program and display raw output
函数exec可以直接执行cmd命令,若有执行结果则返回结果值,同时若写上参数
$output的话则可以把执行结果放入到该数组中. 如果想用户输入的数据被传入
本函数,则需要使用escapeshellarg()或escapeshellcmd()函数来确保用户不能
欺骗系统从而执行任意命令(在安全模式时,命令字符串会被escapeshellcmd()转
义).escapeshellcmd()和escapeshellarg()把用户输入命令进行转义过滤.
mixed call_user_func_array(callback $function,array $param_arr);
–Call a user function given with an array of parameters
<?php
function debug($var, $val)
{
echo "***DEBUGGING\nVARIABLE: $var\nVALUE:";
if (is_array($val) || is_object($val) || is_resource($val)) {
print_r($val);
} else {
echo "\n$val\n";
}
echo "***\n";
}
$c = mysql_connect();
$host = $_SERVER["SERVER_NAME"];
call_user_func_array(‘debug’, array("host", $host));
call_user_func_array(‘debug’, array("c", $c));
call_user_func_array(‘debug’, array("_POST", $_POST));
?>
mixed call_user_func(callback $function[,mixed $parameter[,mixed $...]])
–Call a user function given by the first parameter
<?php
function increment(&$var)
{
$var++;
}
$a = 0;
call_user_func(‘increment’, $a);
echo $a; // 0
call_user_func_array(‘increment’, array(&$a)); // You can use this instead>
echo $a; // 1
?>
>
int func_num_args(void) — Returns the number of arguments passed to the function>
bool function_exists(string $function_name)
– Return TRUE if the given function has been defined.
array func_get_args(void)–Returns an array comprising a function’s argument list
mixed func_get_arg(int $arg_num) — Return an item from the argument list
string create_function(string $args,string $code)
–Creates an anonymous(无记录的) function from the parameters passwd,and return a
unique(独一无二的) name for it.
