Linux bash calculator 感觉用起来蛮方便，至少是偷懒比较方便，嘻嘻
How to:
1.通过命令行
#scale 表示浮点数的精确位数
[root@www ~]# bc
bc 1.06
Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.
3+4
7
scale=2;3/4
.75
ctrl +d
2.通过计算文档统一进行计算
[root@www ~]# vi calc.bc
[root@www ~]# cat calc.bc
3+4
scale=2;3/4
[root@www ~]# bc calc.bc
bc 1.06
Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.
7
.75
ctrl +d
3.数制的转换
#ibase 是指输入的数制，obase是指输出的数制
[root@www ~]# echo 'ibase=10;obase=2;11'|bc
1011