awk + 更改列值并保留双引号

Question

我有这个数据：

$ head test
"Rec Open Date","MSISDN","IMEI"
"2015-01-04",100,200
"2015-01-04",100,200
"2015-01-04",100,200
"2015-01-04",100,200
"2015-01-04",100,200
"2015-01-04",100,200
"2015-01-04",100,200
"2015-01-04",100,200
"2015-01-04",100,200

我可以使用此命令更改第一列的值：

$ awk -F, 'NR>1{="2015-01-05"}1' OFS=, test > tmpfile && mv tmpfile test

用这个命令我松了双引号，我想保留双引号。可以修改此命令以实现此目的吗？

$ head test
"Rec Open Date","MSISDN","IMEI"
2015-01-05,100,200
2015-01-05,100,200
2015-01-05,100,200
2015-01-05,100,200
2015-01-05,100,200
2015-01-05,100,200
2015-01-05,100,200
2015-01-05,100,200
2015-01-05,100,200

Answer 1

来自 GNU Awk 用户指南；

\" A literal double quote (necessary for string constants only). This sequence is used when you want to write a string constant that contains a double quote. Because the string is delimited by double quotes, you need to escape the quote that is part of the string, in order to tell awk to keep processing the rest of the string.

$ awk -F, 'NR>1{="\"2015-01-05\""}1' OFS=, test > tmpfile && mv tmpfile test

$ head test
"Rec Open Date","MSISDN","IMEI"
"2015-01-05",100,200
"2015-01-05",100,200
"2015-01-05",100,200
"2015-01-05",100,200
"2015-01-05",100,200
"2015-01-05",100,200
"2015-01-05",100,200
"2015-01-05",100,200
"2015-01-05",100,200

Answer 2

并不是你是"losing"他们，而是</code>最初是<code>"something"，你用another thing代替了。由于此 another thing 是一个字符串，因此您使用双引号来注释它。因此，要恢复双引号，您需要在替换时注明。

这可以更干净：

awk -v new='"2015-01-05"' 'BEGIN {FS=OFS=","} NR>1{=new}1' file
    ^^^^^^^^^^^^^^^^^^^^^                              ^
         |---------------------------------------------|
    we provide the var ............... and we replace with it
      surrounded by "

awk + ​​更改列值并保留双引号

awk + change column value and keep double quotes

awk

awk + 更改列值并保留双引号