What should I do if exec php cannot be executed?

Solution to the problem that exec php cannot be executed: 1. Modify the first line of the yii file to directly specify the php interpreter; 2. Modify the exec calling method to directly specify the php interpreter.

#The operating environment of this article: Windows 7 system, PHP version 7.1, Dell G3 computer.

Why can't php exec be executed?

Origin

There is a scheduled task. I want to click to start it on the OSS background management page, but I have tried several methods but it doesn’t work; no matter system or exec (manually executing it on the shell command line, there is no problem) ); Initially I suspected a permission issue with the Web Server nginx user, but later found that the environment variable could not find the php executable file (because the nginx user is a restricted user);

Problem location

exec("/home/app/example/api/app/yii demand/virtual {$id}", $output);
print_r($output);

and above After the script is executed, only Array() is output. Obviously, the business code is not executed (the first line of the business code is output);

// http://oss.example.com/index.php?r=demand/demand-ip/msg&id=1929 点击后执行
exec("/home/app/example/api/app/yii demand/virtual {$id} 2>&1", $output);
print_r($output);

There is an error output after the above script is executed: Array ([0] => /usr/bin/env: php: No such file or directory )；

/usr/bin/env: php This The sentence comes from the first line of the yii file #!/usr/bin/env php, which is intended to indicate where the php script interpreter that executes the yii file is; but the error output is /usr/bin /env: php: No such file or directory It means that php cannot be found;

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Solution Solution

• Solution 1: Modify the first line of the yii file to directly specify the php interpreter;
  is changed from #!/usr/bin/env php to # !/usr/local/bin/php, that is, directly specify the location of the php interpreter (you can also modify it when the code is released);
• Option 2: Modify the exec calling method and directly specify the php interpreter.

exec("/usr/local/bin/php /home/app/example/api/app/yii demand/virtual {$id} 2>&1", $output);
print_r($output);

• Note: In actual execution, there are still some problems with the exec command, see "504 Error" below;

504 Error

• When the exec time is too long (such as more than 60 seconds), a 504 error (Gateway Timeout) will appear on the page;
• Need to redirect the standard output and standard error, and then the background process will Execute the command, and the processing process number will be output on the page;

$cmd = '/usr/local/bin/php /home/app/example/yapp/yii demand/finish 2057';
$pid_file = 'msgrepeat.pid';
$exec_cmd = sprintf("%s > /dev/null 2>&1 & echo $! > %s & cat %s", $cmd, $pid_file, $pid_file);
exec($exec_cmd);

About /usr/bin/env (high portability?)

• Why is it better to use “#!/usr/bin/env NAME” instead of “#!/path/to/NAME” as my shebang?
• How does /usr/bin/env know which program to use?

nginx user

For security reasons, the nginx user's shell is usually set to /sbin/nologin

What is the relationship between scheduled tasks and Web operations?

The relationship between scheduled tasks and click operations on the OSS background management page has not been handled well;

1. Two processing methods of the yii framework console and web;
   The issue of how to improve the testability of crontab;
   The issue of how to improve the crontab user experience;
   The issue of how to reasonably reuse crontab tasks and API (Controller/Action) code;
2. Foreground and backend The way to share Controller/Action;
   Or the problem of conveniently sharing code libraries between multiple projects;

Enlightenment

• php-fpm does not work exec, system, shell_exec, only CLI；
• PHP exec() does not run all commands；

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