linux重命名根拥有文件的功能

Question

For some component testing , in my C++ testapp on Ubuntu 14.04, I'd like to rename /sbin/reboot temporarily to prevent my system under test (another big c++ app started inside testapp) from calling system("/sbin/reboot") and after the test I want to restore /sbin/reboot to its full glory.

So on the cmd shell I call

sudo setcap cap_chown,cap_dac_override,cap_setfcap=+ep testapp

in order to enable my testapp to call system("chown user /sbin/reboot") furthermore system("chgrp developer /sbin/reboot") and system("mv /sbin/reboot /sbin/reboot.tmp")

But testapp stops with chown: changing ownership of '/sbin/reboot': Operation not permitted

So, what has to be done to enable renaming this particular file from within an app not running sudo?

Answer 1

For all linux capability experts in the www: the question was - " Which of the linux capabilities does my app need to rename /sbin/reboot withou sudo - to get the same effect as calling sudo mv /sbin/reboot /sbin/reboot.tmp in a shell .

@datenwolf: Without beeing impolite, but if I ask into the crowd "What's the time"? an answer like "you asked the wrong question, because I don't have a watch, but I have a humidity meter, so if you ask about humidity, I am glad to help you" does not help me at all.

The solution to rename a root owned file is, to only set

sudo setcap cap_dac_override=+ep MyTestApp

on commandline, and instead of using

system("mv file1 file2");

in MyTestApp source-code, switch back to

rename("file1" "file2");

Then everything works like a charm.