[Help-bash] What is the best way to push back an element to address@hidden

[Peng Yu]

Hi, I currently use following two ways (1. cmd1& set -- "address@hidden", 2.
cmd2) to push back to address@hidden

Obviously, way 1 is faster, because it will append each element to the
end of the array a, which presumably is independent of the size of the
array a. The drawback is that it involves the temp array a.

Way 2 is much slower, because I understand that the time to add an
element to $@ will increase as the size of $@ increases.

What is best way to push back an element to address@hidden Does anybody have a 
suggestion?

input=($(seq 1000))

function cmd1 {
for x in "address@hidden"
do
    a+=("$x")
done
}

function cmd2 {
for x in "address@hidden"
do
    set -- "$@" "$x"
done
}

bash> cmd

real    0m0.036s
user    0m0.018s
sys    0m0.012s
bash> set -- "address@hidden"

real    0m0.029s
user    0m0.012s
sys    0m0.012s
bash> cmd2

real    0m1.195s
user    0m1.178s
sys    0m0.012s


-- 
Regards,
Peng