Shell编程时出现"[: =: unary operator expected"解决

心已赠人 2022-03-31 08:21 1551阅读 0赞

### 环境 ###

RedHat Linux 9 + VWWare 8.0 + SSH 3.2.9

### 问题 ###

Shell编程时出现如下错误：\[: =: unary operator expected

### 解决 ###

#出现错误代码：
    #第六行出现代码
    values=(39 5 36 12 9 3 2 30 4 18 22 1 28 25)
        numvalues=${#values[@]}
        for (( i=0; i < numvalues; i++ )); do
            lowest=$i
            for (( j=i+1; j < numvalues; j++ )); do
                if [ ${values[j]} -le ${values[$lowest]} ]; then
                    lowest=$j
                fi
            done
              [i]}
            values[i]=${values[lowest]}
            values[lowest]=$temp
        done
        for (( i=0; i < numvalues; i++ )); do
            echo -ne "${values[$i]}\t"
        done
    echo -e "\n\n-------end---------\n"
    
    #解决后代码：
    #在出错的地方增加了一对方括号
    values=(39 5 36 12 9 3 2 30 4 18 22 1 28 25)
        numvalues=${#values[@]}
        for (( i=0; i < numvalues; i++ )); do
            lowest=$i
            for (( j=i+1; j < numvalues; j++ )); do
                if [[ ${values[j]} -le ${values[$lowest]} ]];
             then
                    lowest=$j
                fi
            done
            #[i]}
            values[i]=${values[lowest]}
            values[lowest]=$temp
        done
        for (( i=0; i < numvalues; i++ )); do
            echo -ne "${values[$i]}\t"
        done
    echo -e "\n\n-------end---------\n"

### 参考资料 ###

[http://www.mossfly.com/unary-operator-expected-linux.html][http_www.mossfly.com_unary-operator-expected-linux.html]

[http://blog.csdn.net/goodlixueyong/article/details/6564591][http_blog.csdn.net_goodlixueyong_article_details_6564591]

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[http_www.mossfly.com_unary-operator-expected-linux.html]: http://www.mossfly.com/unary-operator-expected-linux.html
[http_blog.csdn.net_goodlixueyong_article_details_6564591]: http://blog.csdn.net/goodlixueyong/article/details/6564591