过滤命令的输出时，正则表达式错误 [英] regexp error when filtering command output

问题描述

我想将行从以下命令进行过滤：

I want to filter the lines from the following command:

$ cat /proc/net/route
Iface   Destination     Gateway         Flags   RefCnt  Use     Metric  Mask            MTU     Window  IRTT                               
br-lan  01020300        C0A80101        0003    0       0       3       FFFFFF00        0       0       0                                  
br-lan  03043836        C0A80101        0007    0       0       5       FFFFFFFF        0       0       0                                  
br-lan  C0A80100        00000000        0001    0       0       0       FFFFFF00        0       0       0 

我想只提取包含目标行01020300 和面具 FFFFFF00

我试着用下面的正则表达式，但它不工作

I tried with the following regexp but it does not works

cat /proc/net/route | grep "[^ \t\v]\+[ \t\v]\+$dest[ \t\v]\+[^ \t\v]\+[ \t\v]\+[^ \t\v]\+[ \t\v]\+[^ \t\v]\+[ \t\v]\+[^ \t\v]\+[ \t\v]\+[^ \t\v]\+[ \t\v]\+$mask"

我newbe wuth正则表达式的格式。你能不能帮我一个良好的正则表达式这种情况？

I newbe wuth the regexp format. could you help me with a good regexp for this case?

推荐答案

也许更容易与 AWK 来工作了这一点：

Maybe it is easier to work with awk for this:

$ awk '$2=="01020300" && $8=="FFFFFF00"' file
br-lan  01020300        C0A80101        0003    0       0       3       FFFFFF00        0       0       0     

这种方式可以参考第2和第8列，并检查它的价值，而不必担心格式。

This way you can refer to the 2nd and 8th columns and check its value, without having to worry about the format.

如果您的文件，制表符代替空格隔开fiels，使用方法：

In case your file separates fiels with tabs instead of spaces, use:

awk -F"\t" '$2=="01020300" && $8=="FFFFFF00"' file

而如果你想给从bash的变量值这个，你可以做（​​见注释，格伦·杰克曼，伊坦赖斯纳和埃德·莫顿给了很好的解释）：

And in case you want to give this values from bash variables, you can do (see comments, as Glenn Jackman, Etan Reisner and Ed Morton gave nice explanations):

awk -v d="$dest" -v m="$mask" '$2==d && $8==m' file

这篇关于过滤命令的输出时，正则表达式错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！