Shell 如果未手动赋值，则浮点值不起作用

我需要检查百分比变化是否大于0、==0、<0和NULL。 所以我得到了get_count（），它返回SELECT语句的结果…：

get_count () {
    sqlplus -s un/pass <<!
    set heading off
    set feedback off
    set pages 0
    select trunc(PRNCT_CHANGE, 3) 
    FROM SEMANTIC.COUNT_STATISTICS;
   exit;
!
}

count=$(get_count $1) #possible values: -0.789, -10.999, 11.897, 20, 1, 0...

if [ -z "$count" ]; then
    echo "The count percentage change returns null value"
elif [[ "$count" -gt 0 ]]; then
    echo "The count percentage change ($count) is greater than zero"
elif [[ "$count" == 0 ]]; then
    echo "The count percentage change stays unchanged (is zero)"
elif [[ "$count" =~ ^[\-0-9] ]]; then
    echo "The count percentage change is $count" 
else
   echo "$count  ... Something else is wrong here"
fi

这很有效

否则，如果让get_count（）方法返回值，它总是跳转到

else

语句

---

我是否应该以某种方式转换传递给

$count

变量的值？

bash

不理解浮点值。您需要使用像

bc

这样的外部程序来进行比较：

if [ -z "$count" ]; then
    echo "The count percentage change returns null value"
elif [[ $(echo "$count > 0" | bc ) -eq 1 ]]; then
    echo "The count percentage change ($count) is greater than zero"
elif [[ $(echo "$count < 0" | bc ) -eq 1 ]]; then
    echo "The count percentage change ($count) is less than zero"
elif [[ "$count" == 0 ]]; then
    echo "The count percentage change stays unchanged (is zero)"
else
   echo "$count  ... Something else is wrong here"
fi

if[-z“$count”]；然后
echo“计数百分比更改返回空值”
elif[$（echo“$count>0”| bc）-eq 1]；然后
echo“计数百分比变化（$count）大于零”
elif[$（echo“$count<0”| bc）-eq 1]；然后
echo“计数百分比变化（$count）小于零”
elif[“$count”==0]]；然后
echo“计数百分比变化保持不变（为零）”
其他的
echo“$count…这里还有其他问题”
fi

您的

get\u count

实际上没有使用传递给它的参数。是的……我得到了值。因为它得到了回应：“-71.888…这里出了点问题”这就是你的意思吗@chepnerI我只是指出，无论

$1

的值是多少，您的函数都将返回相同的值。在你眼前的问题得到解决之后，这可能是相关的。是的，我对问题的复杂性进行了评论query@chepner

if [ -z "$count" ]; then
    echo "The count percentage change returns null value"
elif [[ $(echo "$count > 0" | bc ) -eq 1 ]]; then
    echo "The count percentage change ($count) is greater than zero"
elif [[ $(echo "$count < 0" | bc ) -eq 1 ]]; then
    echo "The count percentage change ($count) is less than zero"
elif [[ "$count" == 0 ]]; then
    echo "The count percentage change stays unchanged (is zero)"
else
   echo "$count  ... Something else is wrong here"
fi