Shell Programming and Scripting

ok, as told before , after trying to ask or find alternative for sleep which use less memory without any succeed , i decided to delete sleep (or ping ,... ) and run script with while [1] (permanently) , now it doesn't use that 4.7 MEM% of sleep process so this is what i intended to do . (solved somehow with clear questions , but anyway sleep process not used my box memory anymore)
strange part is , probably use while [ 1 ] as permanently loop (which i couldn't see any new row's mem process for that) , use less memory than use while with sleep as top command confirmed!
Best Regards.

Unfortunately that's very inefficient. You will waste a great deal of CPU time and perhaps power. If that's the only thing running on the system though, might be livable.

I continue to think most of that 5% is shared memory, hence not actually wasted. busybox is a big program, but loading it 5 times does not take 5 times the memory.