Unix：用另一个文件中的字符串替换行

Question

文件 1.txt

1.1.1.1

文件2.txt

tcp=ipv4
netmask=255.255.255.0
ip=

所需的输出：

tcp=ipv4
netmask=255.255.255.0
ip=1.1.1.1

我想用 "ip=" 字符串替换 File1.txt 值搜索中的 File2.txt 中的完整行。

我试试：

sed '/ip=/r File1.txt' File2.txt | sed '/ip=/d'

输出：

tcp=ipv4
netmask=255.255.255.0
1.1.1.1

如何添加 "ip=" 字符串值以获得所需的输出？

Answer 1

IP=`cat File1.txt`
sed "/^ip=$/s/$/$IP/" File2.txt

Answer 2

您能否尝试在 GNU awk 中使用所示示例进行跟踪、编写和测试。这也将处理 file1.txt 和 fil2.txt 中的多个出现/值。

awk -F'=' '
BEGIN{ FS=OFS="=" }
FNR==NR{
  arr[++count]=$0
  next
}
/^ip/{
  print $1 OFS arr[++count1]
  next
}
1' file1.txt file2.txt

说明：为上述添加详细说明。

awk  '                      ##Starting awk program from here.
BEGIN{ FS=OFS="=" }
FNR==NR{                   ##Checking condition FNR==NR which will be TRUE when file1.txt is being read.
  arr[++count]=$0          ##Creating arr with index of increasing value of count and its value is current line.
  next                     ##next will skip all further statements from here.
}
/^ip/{                     ##Checking condition if line starts from ip then do following.
  print $1 OFS arr[++count1]   ##Printing current line and arr with index of increasing value of count1.
  next                     ##next will skip all further statements from here.
}
1                          ##1 will print all lines here.
' file1.txt file2.txt      ##Mentioning Input_file names here.