$cmd ='ls -l | grep fileid.php | awk -F "=" \'{if ($2 >= 50) print $2}\'';
print $cmd;
/// outputs: ls -l | grep fileid.php | awk -F "=" '{if ($2 >= 50) print $2}'
// and this command works at bash with output.

// now if I do this:
@result=`cmd`;
//I get: sh: -c: line 0: syntax error near unexpected token `|'