linux - 如何将一个文件中的行替换/添加到另一个文件

Question

我有一个如下例所示的文件，我需要 grep 以 system_props(cat file1 | grep ^system_props) 开头的行..

JAVA_HOME=`find "$AGENT_HOME/jre" -name release -type f 2>/dev/null | sed "s|/release||g"`

system_props="$system_props -sensu.controller.hostName=abc.nam.net"
system_props="$system_props -sensu.controller.port=8181"
system_props="$system_props -sensu.controller.node=Mcagent"

if [ -z "$JAVA_HOME" ]; then
   if [ -d "/opt/middleware" ]; then
      JAVA_HOME=`find /opt/middleware -type d -name jre 2>/dev/null | grep WebSphere | grep java | grep -v grep | sort | uniq`
   fi
fi

我有另一个名为 file2 的文件，其中包含如下所示的虚拟内容。

JAVA_HOME=`find "$AGENT_HOME/jre" -name release -type f 2>/dev/null | sed "s|/release||g"`

system_props="$system_props -sensu.controller.hostName=testhost.net"
system_props="$system_props -sensu.controller.port=8080"

if [ -z "$JAVA_HOME" ]; then
   if [ -d "/opt/middleware" ]; then
      JAVA_HOME=`find /opt/middleware -type d -name jre 2>/dev/null | grep WebSphere | grep java | grep -v grep | sort | uniq`
   fi
fi

现在我的要求是替换cat file1 | 的内容grep ^system_props 到 cat file2 | grep ^system_props)

system_props 行的预期输出应添加到 file2 中，该 file2 与 file1 中的顺序相同。

system_props="$system_props -sensu.controller.hostName=abc.nam.net"
system_props="$system_props -sensu.controller.port=8181"
system_props="$system_props -sensu.controller.node=Mcagent"

Answer 1

您可以尝试关注吗？编写并使用示例进行测试。

awk '
FNR==NR{
  if(match($0,/system_props="/)){
    val=(val?val ORS:"")$0
  }
  next
}
/^system_props="/{
  if(++count==1){
    print val
  }
next
}
1
'  Input_file1   Input_file2

说明:为上述代码添加详细说明。

awk '                                ##Starting awk program from here.
FNR==NR{                             ##Checking condition FNR==NR which will be TRUE when Input_file1 is being read.
  if(match($0,/system_props="/)){    ##Checking condition if match for string system_props=" is found in current line then do following.
    val=(val?val ORS:"")$0           ##Creating variable val and keep appending current line value to its value here.
  }
  next                               ##next will skip all further statements from here.
}
/^system_props="/{                   ##Checking condition if line is starting from sting system_props=" then do following.
  if(++count==1){                    ##Checking condition if variable count is 1 then do following.
    print val                        ##Printing val variable here.
  }
  next                               ##next will skip all further statements from here.
}
1                                    ##1 will print edited/non-edited line here.
'  file1  file2                      ##Mentioning Input_file names here.