sed 與 awk：逐行讀取文件並附加到另一個文件中的特定行

考慮以下兩個文件users.txt：

Arnold.Bosch
David.Ledru
Mehri.Sunny

和docker-compose.txt：

version: '3.9'
services:
 strongswan-server:
   image: vpn-strongswan
   container_name: strongswan-server

   networks:
     strongswan-server:
   environment:
     - STRONGSWAN_CLIENTS=
   sysctls:
   volumes:
   ports:
     - 500:500/udp
     - 4500:4500/udp
volumes:
 strongswan-server-conf:
networks:
 strongswan-server:

以下腳本使用sed過濾器將新使用者添加到包含STRONGSWAN_CLIENTS.

#!/bin/bash
while IFS= read -r line; do
   echo "Text read from file: $line"
 
   sed -i "10s/$/ $line/" $2

done < "$1" 

environment:
 - STRONGSWAN_CLIENTS=Arnold.Bosch David.Ledru Mehri.Sunny

我想知道是否有另一種方法可以基於awk？

這就是你說你想做的事情和你的程式碼做的事情，即附加到 STRONGSWAN_CLIENTS 行的末尾：

$ awk 'NR==FNR{users=users OFS $0; next} /STRONGSWAN_CLIENTS=/{$0=$0 users} 1' users.txt docker-compose.txt
version: '3.9'
services:
 strongswan-server:
   image: vpn-strongswan
   container_name: strongswan-server

   networks:
     strongswan-server:
   environment:
     - STRONGSWAN_CLIENTS=users Arnold.Bosch David.Ledru Mehri.Sunny
   sysctls:
   volumes:
   ports:
     - 500:500/udp
     - 4500:4500/udp
volumes:
 strongswan-server-conf:
networks:
 strongswan-server:

引用自：https://unix.stackexchange.com/questions/711836