linux - sed - 删除匹配模式前后的 n 行

Question

删除匹配模式后的“n”行很容易使用类似的东西:

IFM_MOUNT="/opt/insiteone/fuse-mount2/ifm"
sed -i "\|$IFM_MOUNT|,+6 d" smb.conf (deletes lines matching and next 6 lines)

但我的问题是，我也想删除匹配模式之前的 2 行。

如何实现？我将调用该命令的文件是一个 Samba 配置文件，如下所示:

[DCCAArchive1]
        comment = DCCA Archive File System
        path = /opt/insiteone/fuse-mount1/ifm
        read only = No
        public = yes
        case sensitive = yes
        writable = yes
        create mask=0777
        guest ok = Yes

[DCCAArchive2]
        comment = DCCA Archive File System
        path = /opt/insiteone/fuse-mount2/ifm
        read only = No
        public = yes
        case sensitive = yes
        writable = yes
        create mask=0777
        guest ok = Yes

[DCCAArchive3]
        comment = DCCA Archive File System
        path = /opt/insiteone/fuse-mount3/ifm
        read only = No
        public = yes
        case sensitive = yes
        writable = yes
        create mask=0777
        guest ok = Yes

Answer 1

正如我评论的那样，如果格式是固定的(数据 block 之间的空行)，这一行就可以完成工作:

awk -v RS="" '!/PATTERN/' input

如果不是这种情况，你可以试试这个 awk one-liner:

awk '{a[NR]=$0}/PATTERN/{for(i=NR-2;i<=NR+6;i++)d[i]=1}
     END{for(i=1;i<=NR;i++)if(!d[i])print a[i]}' input

一个测试

• 使用 ifm 作为简化的 PATTERN
• “数据 block ”之间没有空行

• 遵循您的规则:删除行 hit-2 -> hit+6

  kent$  cat f
  fooooooooo
  [DCCAArchive1]
          comment = DCCA Archive File System
          path = /opt/insiteone/fuse-mount1/ifm
          read only = No
          public = yes
          case sensitive = yes
          writable = yes
          create mask=0777
          guest ok = Yes
  barrrrrrrrrrrr
  [DCCAArchive2]
          comment = DCCA Archive File System
          path = /opt/insiteone/fuse-mount2/ifm
          read only = No
          public = yes
          case sensitive = yes
          writable = yes
          create mask=0777
          guest ok = Yes
  
  kent$  awk  '{a[NR]=$0}/ifm/{for(i=NR-2;i<=NR+6;i++)d[i]=1}END{for(i=1;i<=NR;i++)if(!d[i])print a[i]} ' f
  fooooooooo
  barrrrrrrrrrrr
  

编辑

使用来自 shell 变量的模式:

kent$  PAT="/fuse-mount2/ifm"

kent$  awk -v p="$PAT" '{a[NR]=$0}{if(match($0,p)>0){for(i=NR-2;i<=NR+6;i++)d[i]=1}}END{for(i=1;i<=NR;i++)if(!d[i])print a[i]} ' f                                          
fooooooooo
[DCCAArchive1]
        comment = DCCA Archive File System
        path = /opt/insiteone/fuse-mount1/ifm
        read only = No
        public = yes
        case sensitive = yes
        writable = yes
        create mask=0777
        guest ok = Yes
barrrrrrrrrrrr