Which is more efficient - sleep or infinite while?

ashish_uiit · #1 (**permalink**) 08-20-2008

Hi
i need to make a script to check disk space every hour.

****Note that cron is not allowed.

So i need to use either sleep or while 1 ...pls suggest which is more efficient in this scenario?

And is there any other way to do the task?

Thanks,
Ashish

redoubtable · #2 (**permalink**) 08-20-2008

The most efficient and simple way is while and sleep.

Code:

while [ 1 ]
do
    your_stuff...
    sleep 3600
done

ashish_uiit · #3 (**permalink**) 08-20-2008

Quote:

Originally Posted by redoubtable

The most efficient and simple way is while and sleep.

Code:

while [ 1 ]
do
    your_stuff...
    sleep 3600
done

Hi thanks for reply ..
if i use sleep with goto ..will that be moe effiecient as comapred to while 1?

Also what are drawbacks of sleep and while 1.

redoubtable · #4 (**permalink**) 08-20-2008

I would say that's pretty much the same thing (while and goto) but for the sake of simplicity I would advise you go use while.

There are no drawbacks in sleep and while 1. It does it's job and then simply does nothing for 3600 seconds.

broli · #5 (**permalink**) 08-21-2008

actaully, as i have recently learned, [ 1 ] is not the best way

Code:

while :
do
     some stuff
     sleep 11101
done

Perderabo · #6 (**permalink**) 08-21-2008

Quote:

Originally Posted by broli

actaully, as i have recently learned, [ 1 ] is not the best way

Code:

while :
do
     some stuff
     sleep 11101
done

I always use
while : ; do
myself and I would never use
while [ 1 ] ; do
but I wonder why you object to it. I object to it because it is a terribly misleading construct:

Code:

$ [ 1 ] && echo yes
yes
$ [ 0 ] && echo yes
yes
$ [ xyzzy ] && echo yes
yes
$

Few people expect all 3 of those to behave the same. But assuming that : and [ are both shell built-in commands, they should be about as fast.

broli · #7 (**permalink**) 08-21-2008

Quote:

Originally Posted by Perderabo

but I wonder why you object to it. I object to it because it is a terribly misleading construct

well, [ 1 ] implies the shell executes all the code for the builtin test
as i undestand it, the ":" is more closer to null code...
yes, both are built in, but im sure [ has tons of lines to work as the external test (and all the testing capabilitie it has)
: "looks & feels slimer"

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