system
(PHP 4, PHP 5, PHP 7, PHP 8)
system — Execute an external program and display the output
Description
The system() call also tries to automatically
flush the web server's output buffer after each line of output if
PHP is running as a server module.
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.
Parameters
command-
The command that will be executed.
result_code-
If the result_code argument is present, then the
return status of the executed command will be written to this
variable.
Return Values
Returns the last line of the command output on success, and false
on failure.
Examples
Example #1 system() example
<?php
echo '<pre>';
// Outputs all the result of shellcommand "ls", and returns
// the last output line into $last_line. Stores the return value
// of the shell command in $retval.
$last_line = system('ls', $retval);
// Printing additional info
echo '
</pre>
<hr />Last line of the output: ' . $last_line . '
<hr />Return value: ' . $retval;
?>
Notes
WarningWhen allowing user-supplied data to be
passed to this function, use
escapeshellarg() or escapeshellcmd()
to ensure that users cannot trick the system into executing arbitrary
commands.
Note:
If a program is started with this function,
in order for it to continue running in the background, the output of the
program must be redirected to a file or another output stream. Failing to do so
will cause PHP to hang until the execution of the program ends.
shell_exec
Program execution Functions