I gone thro many websites,all provided the same info that we cannot access call_history.db My question is that can we change the access mode for that db using system('chmod 777 /db path/') command ??
You can't, at least on a non-jailbroken phone.
App store apps run in a sandbox. You don't have read/write permission to modify those directories from any app running in its sandbox.
why would you want to a have the information of the call list? also why would you want it to change to such liberal permissions?
you don't have root access on the (non-jailbroken)device, and if you find a way of escalating to root privelages, what are the chances of apple allowing it on the appstore?
1) Jailbreaking is legal. http://www.wired.com/threatlevel/2010/07/feds-ok-iphone-jailbreaking/
2) Listen to http://icin.ch/3Y9Tc to know why you want to access the call logs.
来源：https://stackoverflow.com/questions/3615240/accessing-call-log-history-in-iphone