剪切并替换 bash
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Cut and replace bash
提问by ulkar
I have to process a file with data organized like this
我必须处理一个包含这样组织的数据的文件
AAAAA:BB:CCC:EEEE:DDDD
FF:III:JJJ:KK:LLL
MMMM:NN:OOO:PP
etc
Columns can have different length but lines always have the same number of columns.
列的长度可以不同，但行的列数始终相同。
I want to be able to cut a specific column of a given line and change it to the value I want.
我希望能够剪切给定行的特定列并将其更改为我想要的值。
For example I'd apply my command and change the file to
例如，我会应用我的命令并将文件更改为
AAAAA:BB:XXXX:EEEE:DDDD
FF:III:JJJ:KK:LLL
MMMM:NN:OOO:PP
I know how to select a specific line with sed and then cut the field but I have no idea on how to replace the field with the value I have.
我知道如何使用 sed 选择特定行，然后剪切该字段，但我不知道如何用我拥有的值替换该字段。
Thanks
谢谢
回答by sampson-chen
Here's a way to do it with awk:
这是一种方法awk：
Going with your example, if you wanted to replace the 3rd field of the 1st line:
以您的示例为例，如果您想替换第一行的第三个字段：
awk 'BEGIN{FS=OFS=":"} {if (NR==1) { = "XXXX"}; print}' input_file
Input:
输入：
AAAAA:BB:CCC:EEEE:DDDD
FF:III:JJJ:KK:LLL
MMMM:NN:OOO:PP
Output:
输出：
AAAAA:BB:XXXX:EEEE:DDDD
FF:III:JJJ:KK:LLL
MMMM:NN:OOO:PP
Explanation:
解释：
awk: invoke the awk command'...': everything enclosed by single-quotes are instructions to awkBEGIN{FS=OFS=":"}: Use:as delimiters for both input and output.FSstands for Field Separator.OFSstands for Output Field Separator.if (NR==1) {$3 = "XXXX"};: If Number of Records (NR) read so far is 1, then set the 3rd field ($3) to "XXXX".print: print the current lineinput_file: name of your input file.
awk: 调用 awk 命令'...': 用单引号括起来的所有内容都是 awk 的指令BEGIN{FS=OFS=":"}::用作输入和输出的分隔符。FS代表字段分隔符。OFS代表输出字段分隔符。if (NR==1) {$3 = "XXXX"};：如果NR到目前为止读取的记录数 ( ) 为 1，则将第 3 个字段 ($3) 设置为“XXXX”。print: 打印当前行input_file: 输入文件的名称。
If instead what you are trying to accomplish is simply replace all occurrences of CCCwith XXXXin your file, simply do:
相反，如果您想要完成的只是替换文件中所有出现的CCCwith XXXX，只需执行以下操作：
sed -i 's/CCC/XXXX/g` input_file
Note that this will also replace partial matches, such as ABCCCDD-> ABXXXXDD
请注意，这也会替换部分匹配，例如ABCCCDD->ABXXXXDD
回答by potong
This might work for you (GNU sed):
这可能对你有用（GNU sed）：
sed -r 's/^(([^:]*:?){2})CCC/XXXX/' file
or
或者
awk -F: -vOFS=: '=="CCC"{="XXXX"};1' file
