sleep is a very popular command and we can start sleep from 1 second:
# wait one second please
sleep 1
but what the alternative if I need to wait only 0.1 second or between 0.1 to 1 second ?
- remark: on linux or OS X
sleep 0.XXX
works fine , but on solarissleep 0.1
orsleep 0.01
– illegal syntax
Best Answer
Bash has a "loadable" sleep which supports fractional seconds, and eliminates overheads of an external command:
Then:
The downside is that the loadables may not be provided with your
bash
binary, so you would need to compile them yourself as shown (though on Solaris it would not necessarily be as simple as above).As of
bash-4.4
(September 2016) all the loadables are now built and installed by default on platforms that support it, though they are built as separate shared-object files, and without a.so
suffix. Unless your distro/OS has done something creative (sadly RHEL/CentOS 8 buildbash-4.4
with loadable extensions deliberately removed), you should be able to do instead:(The man page implies
BASH_LOADABLES_PATH
is set automatically, I find this is not the case in the official distribution as of 4.4.12. If and when it is set correctly you need onlyenable -f filename commandname
as required.)If that's not suitable, the next easiest thing to do is build or obtain
sleep
from GNU coreutils, this supports the required feature. The POSIXsleep
command is minimal, older Solaris versions implemented only that. Solaris 11sleep
does support fractional seconds.As a last resort you could use
perl
(or any other scripting that you have to hand) with the caveat that initialising the interpreter may be comparable to the intended sleep time: