更改数据文件中的特定列值

Question

更改数据文件中的特定列值

Ex：文件：input_file.out_RD具有以下数据

6710|GB|LONDON|10
6700|GB|LONDON|20
6703|GB|LONDON|15
6876|GB|LONDON|60

现在想将列号4的值加倍，因此输出文件应为：final_file.out_RD

6710|GB|LONDON|10
6700|GB|LONDON|20
6703|GB|LONDON|15
6876|GB|LONDON|60 

Answer 1

以下脚本有助于解决问题：

#!/bin/sh

#input file from which a specific  column to be multiplied
my_file="/tmp/test/input_file.out_RD"

#multiplication factor value
multiplication_factor=2.00

while IFS= read -r line
do
        #read a line from input file and redirect to temporary file tmp_file.txt
        echo "$line" >tmp_file.txt

        #extract the forth column value from  temp_file.txt
        original_forth_col_value=`awk -F "|" '{print $4}' tmp_file.txt`

        #calculate the final forth column value
        final_forth_col_value=$(echo "$original_forth_col_value * $multiplication_factor" | bc )
        echo $final_forth_col_value

        #place the final forth column value in the output file --> final_file.out_RD
        awk -v fv=$final_forth_col_value  -F "|" 'BEGIN {OFS=FS}{$4=fv;print}' tmp_file.txt >> final_file.out_RD
done < "$my_file"