Bash脚本：变量未正确递增

Question

I am writing a bash script to loop through all the directories and rename the directory to the value of the array, but it seems my (i th) value is not incrementing correctly and it also says "(i th) command not found" when I run my bash script.

Here is my code: I replaced the values inside Unix with place holder values.

#!/bin/bash 

declare -a Unix=(value1 value2 value3 .... );

i = 0
for d in */; do 
    echo ${Unix[$i]}
    #mv $d ${Unix[$i]}
    (($i+1))
done

Answer 1

You are doing two things wrong. Firstly , to answer your problem,

(($i+1))

should be

(($i+=1)) 

also, you should remove the spaces in the line

i = 0 

so it looks like

i=0

Answer 2

Firstly, you might want to quote your directory names in the mv command, or you get into trouble with names containing spaces:

mv "$d" "${Unix[i]}"

As you see, it's not necessary to prepend the i in the index with $ , as [] is an "arithmetic context" here and expands variable names.

Secondly, your increment does nothing: you just add 1 to i and throw the result away. You can use the increment operator instead:

(( ++i ))

Again, the $ is not needed.