[Help-bash] Is `while :` preferred over `while true`?

[Peng Yu]

Hi,

When I run the following command, it seems that `while :` is not
always faster than `while true`. But my understanding is that `while
true` calls the bash internal command `true` but `while :` does not
call anything. So I think `while :` should be always better in terms
of runtime. Is it so? Thanks.

$  ./main.sh
time ./script_true.sh

real    0m1.679s
user    0m1.628s
sys    0m0.038s
time ./script_colon.sh

real    0m1.719s
user    0m1.632s
sys    0m0.055s


==> main.sh <==
#!/usr/bin/env bash
# vim: set noexpandtab tabstop=2:

set -v
time ./script_true.sh
time ./script_colon.sh


==> script_colon.sh <==
#!/usr/bin/env bash
# vim: set noexpandtab tabstop=2:

i=0
while :
do
    if ((i>100000))
    then
        break
    fi
    ((++i))
done


==> script_true.sh <==
#!/usr/bin/env bash
# vim: set noexpandtab tabstop=2:

i=0
while true
do
    if ((i>100000))
    then
        break
    fi
    ((++i))
done



-- 
Regards,
Peng