Issues installing xcode from command line -

so i'm running following

sudo hdiutil attach ~/xcode_7.3.dmg  cp -r /volumes/xcode/xcode.app /applications/ 

however if try run xcode, gives following error after attempting verify xcode. "xcode can't opened because identity of developer cannot confirmed". note if try install traditional way (double click on dmg -> drag applications), don't have problem.

for context: have whole bunch of teamcity servers need install various versions of xcode , love automate it.

i figured out. ran "man cp" , noticed following comment.

historic versions of cp utility had -r option.  implementation supports option; however, use discouraged, not correctly copy special files, symbolic links, or fifo's. 

so changing cp command -r -r fixed it.

rookie mistake me.