When executing PHP under Linux, the external shell script system returns 126

<code><?php
$command = '/var/www/html/fzip.out  /var/www/html/test  /var/www/html/test.fzip';
//$command = 'ls /var/www/html';
system($command,$return);
exec($command,$out);
//echo $command;
print_r($return);
echo '<br>=================<br>';
print_r($out);?></code>

The first $command is your own shell script, the purpose is to compress the folder of the second parameter to the path of the third file. Tell us about the current situation.
1 php.ini is not in safe mode, so you can call ls and other commands normally.
2 When the system executes this command, it returns 126, and the second parameter of exec is empty.
3 The html directory of the generated file has been given 777 permissions, and the compressed test directory also has 777 permissions
4 You can execute this command directly using the command line

What configuration is required to execute such a custom script? ?

Reply content:

<code><?php
$command = '/var/www/html/fzip.out  /var/www/html/test  /var/www/html/test.fzip';
//$command = 'ls /var/www/html';
system($command,$return);
exec($command,$out);
//echo $command;
print_r($return);
echo '<br>=================<br>';
print_r($out);?></code>

The first $command is your own shell script, the purpose is to compress the folder of the second parameter to the path of the third file. Tell us about the current situation.
1 php.ini is not in safe mode, so you can call ls and other commands normally.
2 When the system executes this command, it returns 126, and the second parameter of exec is empty.
3 The html directory of the generated file has been given 777 permissions, and the compressed test directory also has 777 permissions
4 You can execute this command directly using the command line

What configuration is required to execute such a custom script? ?

Finally, I found that execution was blocked by selinux. I will leave a result for your reference. The performance is that in php-cli mode, the script can be executed normally, and execution on the web page returns 126. Adding sudo returns 1