Question

我是shell脚本的新手，也是stackoverflow的新手。 :)我需要你们的帮助

cat Header_list.txt
ID

cat test123123.csv
Name              ID           Portfolio CounterParty Cards ID  Process *Theoretical Model  Issue Date
MUREX_01576184  :MUREX_01576184 :HK-AUFWD   H-CCBC_PM   20229   metals  :BNS Forex  4/27/2016
MUREX_01576194  :MUREX_01576194 :HK-AUFWD   H-CCBC_PM   20229   metals  :BNS Forex  4/27/2016
MUREX_02351193  :MUREX_02351193 :HK-AUFWD   H-CCBC_PM   20229   metals  :BNS Forex  10/31/2016
MUREX_02351197  :MUREX_02351197 :HK-AUFWD   H-CCBC_PM   20229   metals  :BNS Forex  10/31/2016
MUREX_02351203  :MUREX_02351203 :HK-AUFWD   H-CCBC_PM   20229   metals  :BNS Forex  10/31/2016
MUREX_02351207  :MUREX_02351207 :HK-AUFWD   H-CCBC_PM   20229   metals  :BNS Forex  10/31/2016



# here is the main code
awk 'NR==FNR{
            Cols=Cols (Cols?"|":"")$1
            next
        }

 FNR==1{
            for (i=1;i<=NF;i++) 
            if (match($i,Cols)) 
            Ar[++n]=i
       }

       {
           for (i=1;i<=n;i++) 
           printf (i<n)? $(Ar[i])  FS : $(Ar[i])
           printf "\n"
        }' FS=","  Header_list.txt test123123.csv

Expected Output:
ID
:MUREX_01576184
:MUREX_01576194
:MUREX_02351193
:MUREX_02351197
:MUREX_02351203
:MUREX_02351207

Actual 
 ID             Cards ID
:MUREX_01576184 20229
:MUREX_01576194 20229
:MUREX_02351193 20229
:MUREX_02351197 20229
:MUREX_02351203 20229
:MUREX_02351207 20229

在该示例中，它返回标题包含“ID”的所有列。我在想这是导致问题的NR == FNR部分。但我无法理解

的含义

 Cols=Cols (Cols?"|":"")$1
 next

有人可以帮我理解代码吗？如果可能，还要修复代码吗？

Answer 1

问题是match方法，它将正则表达式作为第二个参数。

如果正常比较（==）应该有帮助，请更改此项。

现在我在shell脚本中有以下代码，有人可以帮我修复它并理解代码吗？

1 个答案: