https://yq.aliyun.com/articles/279384
expr % expr
The result of the expression is the "remainder" and it is com‐
puted in the following way. To compute a%b, first a/b is com‐
puted to scale digits. That result is used to compute a-(a/b)*b
to the scale of the maximum of scale+scale(b) and scale(a). If
scale is set to zero and both expressions are integers this
expression is the integer remainder function.
# bc -l
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'.
1/3
.33333333333333333333
--//可以看出使用math 库,缺省scale=20.
--//而如果不使用-l参数scale=0.
--//这样如果在scale=20的情况,取模使用是这样.
12312324/1232
9993.76948051948051948051
12312324-9993.76948051948051948051*1232
.00000000000000001168
scale=2
12312324%1232
11.68
12312324/1232
9993.76
--//bc竟然没做四舍五入.
12312324-9993.76*1232
11.68
===========================
C:Windowssystem32>bc
bc 1.05
Copyright 1991, 1992, 1993, 1994, 1997, 1998 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.
1/3
0
C:Windowssystem32>bc -l
bc 1.05
Copyright 1991, 1992, 1993, 1994, 1997, 1998 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.
1/3
.33333333333333333333
(interrupt) use quit to exit.
C:Windowssystem32>
vim的修改
