bash PHP/Ubuntu - QxcbConnection：无法连接以显示中止
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PHP/Ubuntu - QxcbConnection: Could not connect to display aborted
提问by Rohan Sood
I am using a php script on my apache/ubuntu server to call a bash script that triggers an application taking a python script as an argument (IDAPro).
我在我的 apache/ubuntu 服务器上使用一个 php 脚本来调用一个 bash 脚本，该脚本触发一个将 python 脚本作为参数（IDAPro）的应用程序。
PHP Code
PHP代码
chdir('/var/www/dashboard/team/static/sql');
$output = exec('sudo -u rohan ./start.sh');
Now, the above code works fine if I run the PHP file from the terminal - but only if I run it as the root user. Needless to say, if I execute the bash file directly it runs too.
现在，如果我从终端运行 PHP 文件，上面的代码可以正常工作 - 但前提是我以 root 用户身份运行它。不用说，如果我直接执行 bash 文件，它也会运行。
But when I run the PHP file on the browser, it doesn't work and I get the following error in the apache error log:
但是当我在浏览器上运行 PHP 文件时，它不起作用，我在 apache 错误日志中收到以下错误：
QXcbConnection: Could not connect to display
Aborted
I understand that Apache/php runs as 'www-data' user (used the 'whoami' to verify), and that is why I have the sudo in my exec. I have tweaked and tinkered the permissions for both users to no avail. When I run the php file from the terminal as the 'www-data' user, it throws no error but does not do anything except display the random echo tags I at the start and end of the script to debug it.
我知道 Apache/php 以“www-data”用户身份运行（使用“whoami”进行验证），这就是为什么我的 exec 中有 sudo 的原因。我已经调整并修改了两个用户的权限，但无济于事。当我以“www-data”用户的身份从终端运行 php 文件时，它不会引发任何错误，但除了在脚本的开头和结尾显示随机回显标签 I 以进行调试外，不会执行任何操作。
I am a linux novice, so any help is greatly appreciated.
我是 linux 新手，因此非常感谢任何帮助。
采纳答案by Rohan Sood
Okay, I finally managed to solve it.
好的，我终于设法解决了它。
The issue is not with the permissions, but it is with the environment variables.
问题不在于权限，而在于环境变量。
I had to include the following line in my bash script
我必须在我的 bash 脚本中包含以下行
export DISPLAY=':0.0'
Note that setting the variable in the terminal and running the script does not work. The line needs to be inside the script.
请注意，在终端中设置变量并运行脚本不起作用。该行需要在脚本内。
I assume this is because the DISPLAY variable is not set if you run the script as any user other than root, which is what happens in case of Apache/PHP where the script is executed as the 'www-data' user.
我认为这是因为如果您以 root 以外的任何用户身份运行脚本，则不会设置 DISPLAY 变量，这在 Apache/PHP 的情况下会发生，其中脚本以“www-data”用户身份执行。
回答by Jo?o Dantas
perhaps you could use something like the following at the top of your script:
也许您可以在脚本顶部使用以下内容：
if [ "$(id -un)" != "rohan" ]; then
exec sudo -u rohan ##代码## "$@"
fi
export XAUTHORITY=/home/rohan/.Xauthority
export DISPLAY=:0
