sh -c not get the right output when execute shell script

Question

I loop to get data from array in shell ,
It works when I execute it in a shell file, with this content:

arr=(1 2 3 4 5)  
for var in ${arr[@]};  
do  
    echo $var  
done

But there isn't any output when I use sh -c like below:

sh -c "arr=(1 2 3 4 5);for var in ${arr[@]};do echo $var;done"

Answer 1

Your problem is using sh -c "...", see @Gilles's answer for more details.

Further more, sh (refer to POSIX sh) does not support array (strictly speaking, it has only one array, $@), you need to call other shells on your system, which support array like bash, zsh or ksh.

bash -c 'arr=(1 2 3 4 5);for var in "${arr[@]}";do echo "$var"; done'

另请注意，在${arr[@]}取消引用时您有一个错误，实际上您需要for var in "${arr[@]}"改为。调用不带引号的变量调用 split+glob 并且是许多安全隐患的来源。

要使用 POSIX sh，您可以使用$@：

set -- 1 2 3 4 5
for var do
  printf '%s\n' "$var"
done