shell对比浮点数举例

[2016-10-30  20:21:06 sobey@ubuntu wesoft]$ echo 0.002 '>' 0.2 | bc -l
0
[2016-10-30  20:21:42 sobey@ubuntu wesoft]$ echo 0.002 '<' 0.2 | bc -l
1
[2016-10-30  20:21:51 sobey@ubuntu wesoft]$

[2016-10-30  20:21:51 sobey@ubuntu wesoft]$ if [ $(echo "0.2 <= 4"|bc) = 1 ]; then echo "ok";else echo "fail";fi
ok
[2016-10-30  20:23:24 sobey@ubuntu wesoft]$ if [ $(echo "0.2 <= 0.1"|bc) = 1 ]; then echo "ok";else echo "fail";fi
fail