Question

我想用一位小数减去数字......

我用：

awk -F "," '{$4=$3-$2 ;print $1"," $2"," $3"," $4"}' file.csv

现在我只获得单位，我需要一个小数，我该怎么办？

输入数据

London,18.2,19,1
Liverpool,6.3,9,3
Manchester,15.1,17,2

Answer 1

您可以在printf

中使用awk

awk -F "," '{printf ("%s,%2.1f,%2.1f,%2.1f\n", $1,$2, $3,$3-$2)}' file.cvs

它允许使用类似于C或FORTRAN的字符串格式。您可以在 printf语句中看到man awk。男人的摘录

%f, %F  A floating point number of the form [-]ddd.dddddd.  
   If the system library supports it, %F is available as well. This is  like  %f,
   but  uses capital letters for special “not a number” and “infinity” values.  

%g, %G  Use %e or %f conversion, whichever is shorter, with nonsignificant  
  zeros suppressed.  The %G format uses %E instead of %e.

%s  A character string.  
...

输出

London,18.2,19.0,0.8
Liverpool,6.3,9.0,2.7
Manchester,15.1,17.0,1.9

如果您使用逗号,而不是点.来将小数部分与整数1分开，则这取决于local settings。您可以在选项中为所有系统搜索更改它们，也可以仅为当前shell或子shell更改它们。您可以尝试使用

( LC_ALL=C ; awk -F "," '{printf ("%s,%2.1f,%2.1f,%2.1f\n", $1,$2, $3,$3-$2)}' file.cvs )

( ... )使其在子shell中运行，因此您不会更改当前LC_ALL中shell的值。

Answer 2

以打印方式计算答案：

echo "10.5 1.1" | awk '{print "Solution:" $1-$2}'

在你的情况下：

awk -F "," '{print $1"," $2"," $3"," $3-$2}' file.csv

刚检查了你的代码，并提到了ooga：

awk -F "," '{$4=$3-$2; print $1"," $2"," $3"," $4}' file.csv

没有“最后也应该工作。

减去带小数的数字

2 个答案: