Shell 如何在不将输出写入新文件的情况下将文件转换为日期格式（DD-MMM-yyy）

我在文件中有以下数据，其中是日期列

应转换为如下所示的预期输出 和输出应在同一文件中替换

注意：输出不应写入其他文件

文件中的数据

ABC|2021-05-10T18:25:00.000+0100|TYU|ILP
XYZ|2021-05-14T18:25:00.000+0100|IO|JH
VBNM|2021-05-19T18:25:00.000+0100|KL|KJ

当文件仅作为一列包含日期记录时，我尝试了这段代码，但效果良好。：

预期输出：

ABC|10 MAY 2021|TYU|ILP
XYZ|14 MAY 2021|IO|JH
VBNM|19 MAY 2021|KL|KJ

，然后循环通过传入未格式化日期的每一行，并打印格式化日期

---

这里有很多混乱的bash循环和变通方法。在AWK前后打印资料几乎是不可能的，但这是一个开始。

对于所显示的示例，请尝试以下

AWK

awk '
BEGIN{
  FS=OFS="|"
  num=split("Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sept,Oct,Nov,Dec",month,",")
}
{
  split($2,arr,"[-T]")
  $2=arr[3]" "month[arr[2]+0] " "arr[1]
}
1
'  Input_file

说明：添加上述内容的详细说明

awk '                                     ##Starting awk program from here.
BEGIN{                                    ##Starting BEGIN section of awk program from here.
  FS=OFS="|"                              ##Setting FS and OFS as | here.
                                          ##Creating month array with months names here.
  num=split("Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sept,Oct,Nov,Dec",month,",")
}
{
  split($2,arr,"[-T]")                    ##Splitting 2nd field into arr with delimiter of - or T here.
  $2=arr[3]" "month[arr[2]+0] " "arr[1]   ##Saving arr[3] space month value with index of arr[2] space and value of arr[1] here.
}
1                                         ##printing current line here.
' Input_file                              ##Mentioning Input_file name here.

---

我建议在

while

循环中逐行读取字段，然后用

|

拆分字段

cat filename.txt\
|而IFS=“|”读作abc；做
回显“$A |$（日期-d“$B”+“%d%B%Y”）|$C”
完成

第三列和后续列都存储在

$C

变量中

awk '                                     ##Starting awk program from here.
BEGIN{                                    ##Starting BEGIN section of awk program from here.
  FS=OFS="|"                              ##Setting FS and OFS as | here.
                                          ##Creating month array with months names here.
  num=split("Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sept,Oct,Nov,Dec",month,",")
}
{
  split($2,arr,"[-T]")                    ##Splitting 2nd field into arr with delimiter of - or T here.
  $2=arr[3]" "month[arr[2]+0] " "arr[1]   ##Saving arr[3] space month value with index of arr[2] space and value of arr[1] here.
}
1                                         ##printing current line here.
' Input_file                              ##Mentioning Input_file name here.