exec

(PHP 3, PHP 4 , PHP 5)

exec -- Execute an external program

Popis

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

exec() executes the given command, however it does not output anything. It simply returns 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.

If the output argument is present, then the specified array will be filled with every line of output from the command. Line endings, such as \n, are 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().

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.

Príklad 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');
?>

Varovanie

Ak povol�te, aby d�ta prich�dzaj�ce z u��vate�sk�ho vstupu boli posielan� tejto funkcii, potom by ste mali pou��va� escapeshellarg() alebo escapeshellcmd() pre uistenie sa, �e u��vatelia nem�u prelsti� syst�m na spracovanie �ubovo�n�ch pr�kazov.

Poznámka: Ak spust�te program vyu��vaj�ci t�to funkciu a chcete ho necha� be�a� na pozad�, mus�te sa uisti�, �i je v�stup tohto programu presmerovan� do s�boru alebo nejak�ho in�ho v�stupn�ho pr�du lebo inak PHP zostane vysie� pokia� sa spracovanie programu neskon��.

Poznámka: Ke� je safe mode povolen�, mo�ete iba sp�a� spustiteln� s�bory v r�mci safe_mode_exec_dir. Z praktick�ch d�vodov nie je moment�lne povolen� ma� .. komponenty v ceste k spustite�n�mu s�boru.

Varovanie

S povolen�m safe mode, sa so v�etk�mi slovami n�sleduj�cimi za po�iato�n�m re�azcom pr�kazu zaobch�dza ako s jedn�m argumentom. Teda, echo y | echo x sa st�va echo "y | echo x".

See also system(), passthru(), popen(), escapeshellcmd() pcntl_exec(), and the backtick operator.