exec错误代码2

Question

I'm using Unison to sync files between two servers. I'm trying to get PHP to call it after a file is uploaded.

I'm using exec, but it's returning an error code of 2.

exec("/usr/bin/unison /var/www/html/files ssh://a2//var/www/html/files -batch -prefer newer -times -path uploads", $out, $r);

$out is a blank array, and $r is 2. What does an error code of 2 mean?

P.S. I ran php -a on the command line, and copied and pasted that line, and it worked. Also, exec('whoami') works (and is the same user I was logged in as on the command line).

Answer 1

I fixed it! Using popen (thanks @sberry2A) I saw an error.

Fatal error: Error in creating unison directory /.unison: Permission denied [mkdir(/.unison)]

I ran chdir('/home/user');, before running the command, and then saw an error about HOME not being set.

So, I added HOME=/home/user before the command. Now it works, and I don't need the chdir command either!

exec("HOME=/home/user /usr/bin/unison /var/www/html/files ssh://a2//var/www/html/files -batch -prefer newer -times -path uploads", $out, $r);