i have the following code:
$cmd="lsof | awk '{print $1 \" \" $2 \" \" $3 \" \" $9}'";
$info = shell_exec($cmd);
$processors = preg_split('/\s?\n\s?\n/', trim($info));
$processors = explode("\n",$processors[0]);
foreach($processors as $processor){
echo $processor."\n";
}
when i run it on the command line i get positive results. however, when i run it on a php script i get:
systemd 1 root denied) for each $processor
When I given a try to your code posted, I too got the same errors(was able to re-produce the errors).
Then I tried to put only lsof in place of your complete lsof command with awk to see whats the complete error and I got following error.
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
sh 1 root cwd unknown /proc/1/cwd (readlink: Permission denied)
sh 1 root rtd unknown /proc/1/root (readlink: Permission denied)
sh 1 root txt unknown /proc/1/exe (readlink: Permission denied)
sh 1 root NOFD /proc/1/fd (opendir: Permission denied)
time 9 root cwd unknown /proc/9/cwd (readlink: Permission denied)
time 9 root rtd unknown /proc/9/root (readlink: Permission denied)
After that I googled and found a great link https://unix.stackexchange.com/a/109228 (cross site reference) which tells us that lsof is providing error since we don't have access on those files/commands and obviously we are NOT running command with root.
So to overcome this problem IMHO you could:
lsof command as sudo to get rid of errors, in case your user has sudo access to run this command./dev/null.