2018-09-21 20:06 阅读 124


I have a php file which is called by a website:

example: serial_tx.php?v=W100

Within the php I write a log file where I can see which string v I received (W100 in this case).

The webserver is hosted on a Raspberry Pi and should send this data to the uart.

The files locations:

/SCRIPTS/c/jmsend/serial_tx  // the executable, compiled from a C script

If I am in the root of the webserver and, from the console of my Pi, I run

sudo /var/www/html/SCRIPTS/c/jmsend/serial_tx W100

I get the command sent correctly.

With the php file I tried with system, shell_exec and exec without success.

shell_exec("sudo /var/www/html/SCRIPTS/c/jmsend/serial_tx ".$ric);

$ric is the received command. I tried with different path settings too (starting from Pi root or webserver root). All the files have a 777 as permissions.

  • 点赞
  • 写回答
  • 关注问题
  • 收藏
  • 复制链接分享

1条回答 默认 最新

  • 已采纳
    dongmoyu0336 dongmoyu0336 2018-09-21 20:53

    Something like this in /etc/sudoers should work to allow your web server user to run that particular command without issue:

    Cmnd_Alias SERIAL = /var/www/html/SCRIPTS/c/jmsend/serial_tx *

    Note that you must escape user input before using it:

    $ric = escapeshellarg($_GET["v"]);
    shell_exec("sudo /var/www/html/SCRIPTS/c/jmsend/serial_tx $ric");

    You should also be aware of the differences between exec() and shell_exec(), specifically that you can't check for a failure using shell_exec().

    $ric = escapeshellarg($_GET["v"]);
    exec("sudo /var/www/html/SCRIPTS/c/jmsend/serial_tx $ric", $output, $return);
    if ($return !== 0) {
        // let the user know something didn't work

    This assumes, of course, that your executable is written to return appropriate error codes.

    点赞 评论 复制链接分享