PHP 手冊
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exec

(PHP 3, PHP 4, PHP 5)

exec -- Execute an external program

說明

string exec ( string command [, array &output [, int &return_var]] )

exec() executes the given command.

參數

command: The command that will be executed.
output: If the output argument is present, then the specified array will be filled with every line of output from the command. Trailing whitespace, such as \n, is not included in this array. Note that if the array already contains some elements, exec() will append to the end of the array. If you do not want the function to append elements, call unset() on the array before passing it to exec().
return_var: If the return_var argument is present along with the output argument, then the return status of the executed command will be written to this variable.

返回值

The last line from the result of the command. If you need to execute a command and have all the data from the command passed directly back without any interference, use the passthru() function.

To get the output of the executed command, be sure to set and use the output parameter.

範例

例子 1. An exec() example
<?php // outputs the username that owns the running php/httpd process // (on a system with the "whoami" executable in the path) echo exec('whoami'); ?>

注解

警示

若果想容許會員輸入的資料被傳入本函數，則應使用 escapeshellarg() 或 escapeshellcmd() 函數來確保會員不能欺騙系統從而執行任意指令。

注: 若果用本函數啟動一個程式並希望保持在後台運行，必須確保該程式的輸出被重導至一個檔案或是其它輸出流去，否則 PHP 會在程式執行結束前掛起。

注: 在開啟了安全模式時，只能執行在 safe_mode_exec_dir 之內的程式。為實用起見目前不能在指向程式的路徑中包括 .. 成分。

警示

在開啟了安全模式時，指令字串會被 escapeshellcmd() 轉義。從而 echo y | echo x 就成了 echo "y | echo x"。

參見

system()

passthru()

escapeshellcmd()

pcntl_exec()

system()

backtick operator

後退	起點	前進
escapeshellcmd	上一級	passthru