循环运行Shell脚本时出错

Question

I wrote this shellscript file. But I get error near unexpected token done'`

#!/bin/bash
i=1
while [ $i -lt 12 ]; do
    echo Hi
    i=$[$i+1]
done

Previously, there was no ; before do . I read stackexchange answers and wrote ; after while [] , still I get error. I could not found the resolution online. Any ideas?

Answer 1

i=$[$i+1] this is wrong. You probably meant i=$((i+1))

Answer 2

bash的路径不正确，您错过了将路径更改第一行的根

#!/bin/bash

Answer 3

Correct placement of ; in a bash script can be tricky indeed. Here's a one-liner version of your script with semicolons in the right place:

i=1; while (( i < 12 )); do echo "Hi"; (( i++ )); done

Note that the $ in variables becomes redundant for integer comparisons if placed between double parentheses (( )) .

Answer 4

Works perfectly

$ ./ttt
Hi
Hi
Hi
Hi 
Hi
Hi
Hi
Hi
Hi
Hi 
Hi
$ cat ttt
#!/bin/bash
i=1
while [ $i -lt 12 ]; do
    echo Hi
    i=$[$i+1]
done  
$