脚本执行，出现如下错误：“h.sh: line 9: [: ==: unary operator expected”，具体脚本如下：

[root@Dasoncheng sbin]# cat -n h.sh      1	#!/bin/bash     2	sh -n $1 &>/tmp/err     3	if [ $? -eq 0 ];     4	then     5	    echo "The script is ok"     6	else     7	    cat /tmp/err     8	    read -p "Please input q/Q to exit , or others to edit it by vim: " n     9	    if [ $n == "q" ] || [ $n == "Q" ];    10	    then    11	        exit    12	    else    13	        vim $1    14	        exit    15	    fi    16	fi[root@Dasoncheng sbin]# sh h.sh i.sh i.sh: line 3: syntax error: unexpected end of filePlease input q/Q to exit , or others to edit it by vim: h.sh: line 9: [: ==: unary operator expectedh.sh: line 9: [: ==: unary operator expected  ##这个就是执行的报错信息；

解决办法：

if [ $n == "q" ] || [ $n == "Q" ];修改为：if [ "$n" == "q" ] || [ "$n" == "Q" ];##即可；

因为当$n为空值时（即回车 未输入任何参数），那么就成了 [ = "q"]了，显然缺少了对比参数。当$n值不为空时，脚本还是正常的；

if [[ $n == "q" ]] || [[ $n == "Q" ]]##或者if [ "$n"x == "q"x ] ##其中x也可以为其他字符；