这里是我的脚本,其相当不言自明:“无效的算术运算符”在bash做浮点运算
d1=0.003
d2=0.0008
d1d2=$((d1 + d2))
mean1=7
mean2=5
meandiff=$((mean1 - mean2))
echo $meandiff
echo $d1d2
但是,而不是领我预期的输出: 0.0038 我得到错误Invalid Arithmetic Operator, (error token is ".003")?
这里是我的脚本,其相当不言自明:“无效的算术运算符”在bash做浮点运算
d1=0.003
d2=0.0008
d1d2=$((d1 + d2))
mean1=7
mean2=5
meandiff=$((mean1 - mean2))
echo $meandiff
echo $d1d2
但是,而不是领我预期的输出: 0.0038 我得到错误Invalid Arithmetic Operator, (error token is ".003")?
bash
不支持浮点运算。您需要使用外部工具,如bc
。
# Like everything else in shell, these are strings, not
# floating-point values
d1=0.003
d2=0.0008
# bc parses its input to perform math
d1d2=$(echo "$d1 + $d2" | bc)
# These, too, are strings (not integers)
mean1=7
mean2=5
# $((...)) is a built-in construct that can parse
# its contents as integers; valid identifiers
# are recursively resolved as variables.
meandiff=$((mean1 - mean2))
当我将算法更改为format = $((echo“”| bc))时,它仍然抱怨? –
这是一个错字,很抱歉。应该是'$(...)',而不是'$((...))'。命令替换和算术扩展有点过于相似。 – chepner
不用谢谢你的帮助 –
顺便说一句,如果您从bash切换到ksh93,浮点将本机可用。 –