awk怎么啦？高人请进

qinghan1125

$ echo "0.56" | awk '{printf "%d\n",$1*100}'    # 打印正确56
$ echo "0.57" | awk '{printf "%d\n",$1*100}'    # 这里居然出来56！56
$  echo "0.58" | awk '{printf "%d\n",$1*100}'   # 这里居然出来是57！57
$ echo "0.59" | awk '{printf "%d\n",$1*100}'    # 打印正确

经过多次测试，仅发现对0.57,0.58这两个数会有这种现象

爱在Cookies

估计是二进制转换精确度问题吧。

jason680

$ echo "0.56" | awk '{printf "%d\n",$1*100}'    # 打印正确56
$ echo "0.57" | awk '{printf "%d\n",$1 ...
qinghan1125 发表于 2010-11-23 16:59

#  echo "0.55" | awk '{printf "%2.20f\n",$1*100}'
55.00000000000000710543

#  echo "0.56" | awk '{printf "%2.20f\n",$1*100}'
56.00000000000000710543

#  echo "0.57" | awk '{printf "%2.20f\n",$1*100}'
56.99999999999999289457

#  echo "0.58" | awk '{printf "%2.20f\n",$1*100}'
57.99999999999999289457

#  echo "0.59" | awk '{printf "%2.20f\n",$1*100}'
59.00000000000000000000



#  echo "0.56" | awk '{printf "%2.0f\n",$1*100}'
56
#  echo "0.57" | awk '{printf "%2.0f\n",$1*100}'
57
#  echo "0.58" | awk '{printf "%2.0f\n",$1*100}'
58

dibug

awk '{printf "%.0f\n",$1*100}'

blackold

see http://bbs.chinaunix.net/thread-1675612-1-1.html

L_kernel

1. $ echo "0.57" | awk '{printf "%d\n",$1*100+0.5}'  
   
2. 57
   
3. $ echo "0.58" | awk '{printf "%d\n",$1*100+0.5}'
   
4. 58

复制代码

cjaizss

太正常了，因为浮点数无法准确表示0.57

lilyadcms03

回复 3# jason680

透彻，一目了然！。呵呵