在 AWK 中删除列选择

Question

我想从 CSV 文件列表中删除选择的列。 awk 调用是内联的，因为它在 shell 脚本中使用。我事先不知道这些文件有多少列，只知道我想要删除的列包含在列表的每个文件中。

假设我想删除前 4 列。删除列值会留下分隔符，我也想去掉。

尽管以下方法可行：创建要删除的列号数组，然后重新创建没有这些列的相应行。

下面的length(row)值符合预期，但最终循环仍然迭代原始列数，而不是实际的length(row)值。

头 $f | awk 'BEGIN{FS=",";split("1,2,3,4",dropers,",")}{split($0,row,FS);for(i in dropers) 删除行[i] ;打印 NF ","length(row) ">>";for(i=1;i $g

或格式化：

head $f | awk 'BEGIN{FS=",";split("1,2,3,4",dropers,",")}{split($0,row,FS);for(i in dropers) delete row[i]; print NF "," length(row) "<<<";out=""; print NF "," length(row) ">>>";for(i=1;i<=length(row);i++){print row[i] "lulu"; out = out "," row[i]}; sub(/[ \t]*$/,"",out);print out}'  > $g

这是 2 个文件的输出：进入 6 列，当我删除第 1 到第 4 列时剩下 2 列，但循环遍历完整的 6 列而不是预期的 2。感谢您的任何建议。

澳大利亚。

6,2<<<
6,2>>>
lulu
lulu
lulu
lulu
0000009lulu
461474lulu
,,,,,0000009,461474
6,2<<<
6,2>>>
lulu
lulu
lulu
lulu
0000010lulu
94942lulu
,,,,,0000010,94942

编辑（贝利撒留）
格式化代码如下：

BEGIN {FS=",";
       split("1,2,3,4",dropers,",")
      }

{ split($0,row,FS);
  for(i in dropers) delete row[i]; 
  print NF "," length(row) "<<<";
  out=""; 
  print NF "," length(row) ">>>";
  for(i=1;i<=length(row);i++){print row[i] "lulu"; 
                              out = out "," row[i]}; 
  sub(/[ \t]*$/,"",out);
  print out
}

Answer 1

BEGIN {FS=",";
       split("1,2,3,4",dropers,",")
      }

{ split($0,row,FS);
  for(i in dropers) delete row[i]; 
  print NF "," length(row) "<<<";
  out=""; 
  print NF "," length(row) ">>>";
  for(i in row){print row[i] "lulu"; 
                out = out "," row[i]}; 
  out = substr(out,2)
  sub(/[ \t]*$/,"",out);
  print out
}

带输入：

a,b,c,d,e,f,g

打印：

7,3<<<
7,3>>>
elulu
flulu
glulu
e,f,g